knitr::opts_chunk$set(echo = TRUE)
library(lavaan)
## This is lavaan 0.6-15
## lavaan is FREE software! Please report any bugs.
library(semTools)
## 
## ###############################################################################
## This is semTools 0.5-6
## All users of R (or SEM) are invited to submit functions or ideas for functions.
## ###############################################################################
library(semPlot)
library(haven) 
library(psych)
## 
## Attaching package: 'psych'
## The following objects are masked from 'package:semTools':
## 
##     reliability, skew
## The following object is masked from 'package:lavaan':
## 
##     cor2cov
library(GAIPE)
library(naniar) #downloading packages
HW2_TimeData <- read.csv("WLS_HW2_Time.csv", header=TRUE)
head(HW2_TimeData) #reading in data file
##    idpub sexrsp byear educ92 age04 age11 Simil_2004 Digits_2004 LFLU_2004
## 1 905087      1    37     13    66    NA          8          12        12
## 2 905118      2    39     12    65    71          2           9        13
## 3 901295      2    40     12    64    70         10          10         8
## 4 922383      2    38     12    66    NA          0          NA         6
## 5 904612      1    38     12    65    73          4           9         6
## 6 900877      1    37     12    66    73          7           7        14
##   CFLU_2004 Simil_2011 Digits_2011 LFLU_2011 CFLU_2011 TotRecall_2004
## 1        17         NA          NA        NA        NA             12
## 2        NA          3           9        13        NA              9
## 3        NA          7           7        11        NA              6
## 4        16         NA          NA        NA        NA             NA
## 5        18          6          10         7        23              9
## 6        NA          6           8         7        NA              9
##   TotRecall_2011 N_04 N_11
## 1             NA    4    0
## 2             11    3    3
## 3              9    3    3
## 4             NA    3    0
## 5             11    4    4
## 6             10    3    3
TimeData_TD<-HW2_TimeData[,(1:6)] #subsetting demographic variables of interest

TimeData_T <- HW2_TimeData[,(7:14)] #subsetting variables of interest (cog items)

TimeData_T1 <- TimeData_T[,(1:4)] #subsetting T1 variables of interest

TimeData_T2 <- TimeData_T[,(5:8)] #subsetting T2 variables of interest
vis_miss(TimeData_T1) #viewing missingness at T1. There does seem to be quite a bit of missingess; however, missing data will be estimated using FIML.
## Warning: `gather_()` was deprecated in tidyr 1.2.0.
## ℹ Please use `gather()` instead.
## ℹ The deprecated feature was likely used in the visdat package.
##   Please report the issue at <]8;;https://github.com/ropensci/visdat/issueshttps://github.com/ropensci/visdat/issues]8;;>.

vis_miss(TimeData_T2) #viewing missingness at T2. There does seem to be quite a bit of missingess; however, missing data will be estimated using FIML.

alpha(TimeData_T1) #calculating cronbach's alpha for T1 variables. Alpha values for WAIS 2004 (α = .47), Digit Ordering 2004 (α = .52), Letter Fluency 2004 (α = .42), Category Fluency 2004 (α = .43) were all less than what has been generally considered acceptable (i.e., α = .70 or higher). 
## Number of categories should be increased  in order to count frequencies.
## 
## Reliability analysis   
## Call: alpha(x = TimeData_T1)
## 
##   raw_alpha std.alpha G6(smc) average_r S/N    ase mean  sd median_r
##        0.5      0.53    0.47      0.22 1.1 0.0084  9.3 3.4     0.21
## 
##     95% confidence boundaries 
##          lower alpha upper
## Feldt     0.48   0.5  0.52
## Duhachek  0.49   0.5  0.52
## 
##  Reliability if an item is dropped:
##             raw_alpha std.alpha G6(smc) average_r  S/N alpha se   var.r med.r
## Simil_2004       0.46      0.47    0.38      0.23 0.90   0.0099 0.00823  0.19
## Digits_2004      0.48      0.52    0.42      0.27 1.08   0.0090 0.00351  0.23
## LFLU_2004        0.34      0.42    0.32      0.19 0.72   0.0110 0.00103  0.18
## CFLU_2004        0.40      0.43    0.34      0.20 0.76   0.0114 0.00079  0.19
## 
##  Item statistics 
##                n raw.r std.r r.cor r.drop mean  sd
## Simil_2004  6808  0.54  0.64  0.42   0.31  6.6 2.4
## Digits_2004 5310  0.48  0.60  0.34   0.24  7.2 3.1
## LFLU_2004   4952  0.63  0.68  0.51   0.38 11.4 4.4
## CFLU_2004   3246  0.81  0.67  0.49   0.37 20.9 6.1
alpha(TimeData_T2) #calculating cronbach's alpha for T2 variables. Alpha values for WAIS 2011 (α = .56), Digit Ordering 2011 (α = .54), Letter Fluency 2011 (α = .48), and Category Fluency 2011 (α = .49) were all less than what has been generally considered acceptable (i.e., α = .70 or higher). 
## Number of categories should be increased  in order to count frequencies.
## 
## Reliability analysis   
## Call: alpha(x = TimeData_T2)
## 
##   raw_alpha std.alpha G6(smc) average_r S/N    ase mean sd median_r
##       0.55      0.59    0.52      0.26 1.4 0.0075  9.5  3     0.26
## 
##     95% confidence boundaries 
##          lower alpha upper
## Feldt     0.53  0.55  0.56
## Duhachek  0.53  0.55  0.56
## 
##  Reliability if an item is dropped:
##             raw_alpha std.alpha G6(smc) average_r  S/N alpha se   var.r med.r
## Simil_2011       0.52      0.56    0.46      0.29 1.25   0.0086 0.00211  0.27
## Digits_2011      0.49      0.54    0.44      0.28 1.16   0.0087 0.00364  0.25
## LFLU_2011        0.40      0.48    0.39      0.24 0.94   0.0095 0.00083  0.24
## CFLU_2011        0.46      0.49    0.39      0.24 0.96   0.0100 0.00098  0.25
## 
##  Item statistics 
##                n raw.r std.r r.cor r.drop mean  sd
## Simil_2011  5400  0.51  0.63  0.41   0.31  6.4 2.3
## Digits_2011 4252  0.52  0.65  0.45   0.34  6.8 2.6
## LFLU_2011   5052  0.70  0.70  0.54   0.42 11.2 4.2
## CFLU_2011   2559  0.83  0.69  0.53   0.41 19.6 6.0
describe(TimeData_TD) #finding descriptives of demographic variables. Females make up a little over half of the sample. Participants' mean age is reaching emerging older adulthood at T1. Participants' mean age has reached older adulthood at T2. Mean number of years of education based on highest degree earned was 13.71. Skewness and kurtosis do not seem to be an issue, they are all acceptable. Data seem to meet normality assumptions. No outliers seem to be present. 
##        vars    n      mean      sd   median   trimmed      mad    min    max
## idpub     1 7078 916920.25 9813.33 916866.5 916905.45 12668.82 900021 933957
## sexrsp    2 7078      1.54    0.50      2.0      1.55     0.00      1      2
## byear     3 7078     38.86    0.50     39.0     38.91     0.00     37     40
## educ92    4 6858     13.71    2.30     12.0     13.32     0.00     12     21
## age04     5 7078     64.35    0.71     64.0     64.34     0.00     63     67
## age11     6 5534     71.22    0.92     71.0     71.14     1.48     70     74
##        range  skew kurtosis     se
## idpub  33936  0.01    -1.20 116.64
## sexrsp     1 -0.15    -1.98   0.01
## byear      3 -1.04     2.77   0.01
## educ92     9  1.05    -0.17   0.03
## age04      4  0.48     0.54   0.01
## age11      4  0.59    -0.02   0.01
describe(TimeData_T1) #finding descriptives of variables of interest at T1. Means of simil_2004 and digits_2004 are lower than means for LFLU_2004 and CFLU_2004. Skewness and kurtosis do not seem to be an issue, they are all acceptable. Data seem to meet normality assumptions.
##             vars    n  mean   sd median trimmed  mad min max range  skew
## Simil_2004     1 6808  6.58 2.38      7    6.60 2.97   0  12    12 -0.06
## Digits_2004    2 5310  7.23 3.07      7    7.44 2.97   0  12    12 -0.51
## LFLU_2004      3 4952 11.44 4.35     11   11.25 4.45   0  31    31  0.44
## CFLU_2004      4 3246 20.85 6.14     20   20.65 5.93   0  47    47  0.35
##             kurtosis   se
## Simil_2004     -0.46 0.03
## Digits_2004    -0.02 0.04
## LFLU_2004       0.26 0.06
## CFLU_2004       0.33 0.11
describe(TimeData_T2) #finding descriptives of variables of interest at T2. Means of simil_2011 and digits_2011 are lower than means for LFLU_2011 and CFLU_2011.Skewness and kurtosis do not seem to be an issue, they are all acceptable. Data seem to meet normality assumptions.
##             vars    n  mean   sd median trimmed  mad min max range  skew
## Simil_2011     1 5400  6.36 2.32      6    6.34 2.97   0  12    12  0.03
## Digits_2011    2 4252  6.81 2.63      6    6.94 2.97   0  12    12 -0.45
## LFLU_2011      3 5052 11.21 4.18     11   11.05 4.45   0  31    31  0.38
## CFLU_2011      4 2559 19.60 5.97     19   19.48 5.93   0  47    47  0.21
##             kurtosis   se
## Simil_2011     -0.44 0.03
## Digits_2011     0.42 0.04
## LFLU_2011       0.09 0.06
## CFLU_2011       0.54 0.12
SexT1 <- factor(TimeData_TD$sexrsp, levels = 1:2, labels = c("Male", "Female")) #turning sex into a factor
summary(SexT1) #getting summary/frequency of sex. Females made up approximately 54% (n = 3,801) and males made up approximately 46% (n = 3,277) of the sample. 
##   Male Female 
##   3277   3801

Variable means and standard deviations decreased slightly across time.

var(TimeData_TD$sexrsp)
## [1] 0.2486649
var(TimeData_TD$byear) 
## [1] 0.2460696
var(TimeData_T1$Simil_2004, na.rm=TRUE)
## [1] 5.657111
var(TimeData_T1$Digits_2004, na.rm=TRUE)
## [1] 9.417145
var(TimeData_T1$LFLU_2004, na.rm=TRUE)
## [1] 18.94036
var(TimeData_T1$CFLU_2004, na.rm=TRUE) #finding variances of participants' sex, birth year, and cognitive measures at T1. All variances do not warrant concern.
## [1] 37.75414
var(TimeData_TD$sexrsp)
## [1] 0.2486649
var(TimeData_TD$byear) 
## [1] 0.2460696
var(TimeData_T2$Simil_2011, na.rm=TRUE)
## [1] 5.384844
var(TimeData_T2$Digits_2011, na.rm=TRUE)
## [1] 6.90269
var(TimeData_T2$LFLU_2011, na.rm=TRUE)
## [1] 17.48802
var(TimeData_T2$CFLU_2011, na.rm=TRUE) #finding variances of participants' sex, birth year, and cognitive measures at T2. All variances do not warrant concern.
## [1] 35.66045
corMat <- cor(HW2_TimeData, use = "pairwise.complete.obs")
corMat #correlation matrix. No item shared a coefficient large enough to warrant concern for multicollinearity. Based on correlation coefficients, no items shared a coefficient large enough to warrant concern for multicollinearity (all r’s ≤ .59). In addition, relationships between age at time point 1 and 2 and cognitive functioning variables were weak and negative. Education and cognitive functioning variables had a weak to moderate, positive relationship. Also, within-time variables were weakly associated at time point 1 (r = .17-.34) and time point 2 (r = .21-.35), thus variables exhibited good test-retest reliability and measure different components of overall cognitive functioning. Time point 1 cognitive functioning variables had strong, positive associations with the same variables at time point 2 (r < .50), except for the Digit Ordering variable, which had a moderate, positive association from time point 1 to time point 2 (r < .35). 
##                        idpub       sexrsp        byear      educ92       age04
## idpub           1.0000000000 -0.005308263  0.006871993  0.00337777 -0.01151801
## sexrsp         -0.0053082626  1.000000000  0.110564254 -0.16200261 -0.09015242
## byear           0.0068719927  0.110564254  1.000000000  0.13381537 -0.56774438
## educ92          0.0033777703 -0.162002605  0.133815369  1.00000000 -0.10763001
## age04          -0.0115180085 -0.090152422 -0.567744375 -0.10763001  1.00000000
## age11          -0.0254198991 -0.027381266 -0.430587301 -0.13831503  0.42456697
## Simil_2004      0.0171345646  0.001839766  0.147486416  0.38315537 -0.14487527
## Digits_2004     0.0260883796  0.079716217  0.137958318  0.17248550 -0.13175250
## LFLU_2004       0.0115240402  0.120019945  0.096690054  0.21692665 -0.09089293
## CFLU_2004       0.0009888218  0.149956418  0.124615114  0.25304066 -0.11155449
## Simil_2011     -0.0045767474 -0.019505341  0.146671506  0.37633723 -0.13103808
## Digits_2011     0.0189885631  0.044389664  0.123559119  0.17840004 -0.13508921
## LFLU_2011       0.0101217591  0.136385641  0.131554061  0.24523448 -0.11727568
## CFLU_2011       0.0223604114  0.164166325  0.128996328  0.19733989 -0.08882468
## TotRecall_2004  0.0026152467  0.255187644  0.095912290  0.13664526 -0.07762805
## TotRecall_2011  0.0105892632  0.236808047  0.166278052  0.16438511 -0.13781502
## N_04           -0.0228501975  0.009320027  0.038472019  0.01902736 -0.06960679
## N_11           -0.0072923491 -0.002311953  0.044665930  0.09361322 -0.08213913
##                      age11   Simil_2004 Digits_2004    LFLU_2004     CFLU_2004
## idpub          -0.02541990  0.017134565  0.02608838  0.011524040  0.0009888218
## sexrsp         -0.02738127  0.001839766  0.07971622  0.120019945  0.1499564176
## byear          -0.43058730  0.147486416  0.13795832  0.096690054  0.1246151136
## educ92         -0.13831503  0.383155375  0.17248550  0.216926654  0.2530406626
## age04           0.42456697 -0.144875274 -0.13175250 -0.090892928 -0.1115544855
## age11           1.00000000 -0.145524530 -0.09946018 -0.100222416 -0.1226535281
## Simil_2004     -0.14552453  1.000000000  0.18568314  0.238716614  0.2349456386
## Digits_2004    -0.09946018  0.185683142  1.00000000  0.190241061  0.1690607562
## LFLU_2004      -0.10022242  0.238716614  0.19024106  1.000000000  0.3370050497
## CFLU_2004      -0.12265353  0.234945639  0.16906076  0.337005050  1.0000000000
## Simil_2011     -0.16896115  0.556810600  0.15011026  0.205458267  0.2384257351
## Digits_2011    -0.11321128  0.163421925  0.34789799  0.210788789  0.2326793004
## LFLU_2011      -0.11945583  0.239586951  0.19556915  0.591650184  0.3155062961
## CFLU_2011      -0.13170105  0.218056814  0.17845534  0.296953581  0.5905127640
## TotRecall_2004 -0.05681533  0.125805029  0.30052972  0.176975804  0.2010712961
## TotRecall_2011 -0.13482718  0.229851012  0.21725412  0.201517136  0.2653682210
## N_04           -0.01576978  0.116262831  0.01448163  0.002896705  0.0951432560
## N_11           -0.02770080  0.130674051  0.04261629  0.079454664  0.1162335475
##                  Simil_2011 Digits_2011   LFLU_2011   CFLU_2011 TotRecall_2004
## idpub          -0.004576747  0.01898856  0.01012176  0.02236041    0.002615247
## sexrsp         -0.019505341  0.04438966  0.13638564  0.16416633    0.255187644
## byear           0.146671506  0.12355912  0.13155406  0.12899633    0.095912290
## educ92          0.376337229  0.17840004  0.24523448  0.19733989    0.136645258
## age04          -0.131038085 -0.13508921 -0.11727568 -0.08882468   -0.077628046
## age11          -0.168961152 -0.11321128 -0.11945583 -0.13170105   -0.056815331
## Simil_2004      0.556810600  0.16342193  0.23958695  0.21805681    0.125805029
## Digits_2004     0.150110259  0.34789799  0.19556915  0.17845534    0.300529721
## LFLU_2004       0.205458267  0.21078879  0.59165018  0.29695358    0.176975804
## CFLU_2004       0.238425735  0.23267930  0.31550630  0.59051276    0.201071296
## Simil_2011      1.000000000  0.20951685  0.24995424  0.24298900    0.109913707
## Digits_2011     0.209516848  1.00000000  0.27392305  0.27039944    0.146164190
## LFLU_2011       0.249954240  0.27392305  1.00000000  0.34936256    0.192947526
## CFLU_2011       0.242989005  0.27039944  0.34936256  1.00000000    0.206898949
## TotRecall_2004  0.109913707  0.14616419  0.19294753  0.20689895    1.000000000
## TotRecall_2011  0.263933247  0.25748201  0.25687735  0.30583860    0.362090540
## N_04            0.045494272  0.01918534  0.02687200  0.02058211    0.038936317
## N_11            0.051935223  0.04426760  0.01561521  0.09634205    0.041379857
##                TotRecall_2011         N_04         N_11
## idpub              0.01058926 -0.022850197 -0.007292349
## sexrsp             0.23680805  0.009320027 -0.002311953
## byear              0.16627805  0.038472019  0.044665930
## educ92             0.16438511  0.019027363  0.093613219
## age04             -0.13781502 -0.069606795 -0.082139127
## age11             -0.13482718 -0.015769777 -0.027700803
## Simil_2004         0.22985101  0.116262831  0.130674051
## Digits_2004        0.21725412  0.014481631  0.042616285
## LFLU_2004          0.20151714  0.002896705  0.079454664
## CFLU_2004          0.26536822  0.095143256  0.116233548
## Simil_2011         0.26393325  0.045494272  0.051935223
## Digits_2011        0.25748201  0.019185340  0.044267602
## LFLU_2011          0.25687735  0.026871999  0.015615212
## CFLU_2011          0.30583860  0.020582107  0.096342054
## TotRecall_2004     0.36209054  0.038936317  0.041379857
## TotRecall_2011     1.00000000  0.021339543  0.035201834
## N_04               0.02133954  1.000000000  0.380387431
## N_11               0.03520183  0.380387431  1.000000000
covMat <- cov(HW2_TimeData, use = "pairwise.complete.obs")
covMat #covariance matrix. Matrix appears normal, no causes of concern for items. Diagonal elements of the variance/covariance matrix decreased slightly across time.
##                        idpub        sexrsp       byear      educ92        age04
## idpub           9.630140e+07 -25.976221819 33.45245270 76.27440740 -79.83193624
## sexrsp         -2.597622e+01   0.248664940  0.02734960 -0.18574520  -0.03175175
## byear           3.345245e+01   0.027349600  0.24606958  0.15187346  -0.19891373
## educ92          7.627441e+01  -0.185745203  0.15187346  5.28943410  -0.17302605
## age04          -7.983194e+01  -0.031751748 -0.19891373 -0.17302605   0.49884534
## age11          -2.299804e+02  -0.012586439 -0.19670455 -0.30006221   0.26989788
## Simil_2004      3.991450e+02   0.002182165  0.17333070  2.09102156  -0.24187824
## Digits_2004     7.826589e+02   0.121934965  0.20652436  1.22397854  -0.27440473
## LFLU_2004       4.899378e+02   0.260187846  0.20358504  2.19548522  -0.27152235
## CFLU_2004       5.881858e+01   0.459651941  0.37705917  3.62154933  -0.47671692
## Simil_2011     -1.045130e+02  -0.022579078  0.16913832  2.06106307  -0.20976724
## Digits_2011     4.882571e+02   0.058183477  0.15718613  1.10982916  -0.23940734
## LFLU_2011       4.175385e+02   0.284057797  0.27022839  2.42386590  -0.33441980
## CFLU_2011       1.299244e+03   0.489563579  0.37530786  2.80755167  -0.35986359
## TotRecall_2004  9.391789e+01   0.467079738  0.17235568  1.16511815  -0.19413600
## TotRecall_2011  3.013551e+02   0.343295182  0.23389400  1.13429372  -0.27067073
## N_04           -2.725737e+02   0.005649397  0.02319806  0.05320233  -0.05976023
## N_11           -1.097166e+02  -0.001767563  0.03396987  0.32811365  -0.08894501
##                        age11    Simil_2004 Digits_2004     LFLU_2004  CFLU_2004
## idpub          -229.98035838 399.144970197 782.6589198 489.937830113 58.8185802
## sexrsp           -0.01258644   0.002182165   0.1219350   0.260187846  0.4596519
## byear            -0.19670455   0.173330700   0.2065244   0.203585036  0.3770592
## educ92           -0.30006221   2.091021558   1.2239785   2.195485222  3.6215493
## age04             0.26989788  -0.241878241  -0.2744047  -0.271522349 -0.4767169
## age11             0.84917707  -0.317451191  -0.2751803  -0.397880823 -0.6991227
## Simil_2004       -0.31745119   5.657111437   1.3311314   2.417781727  3.3461103
## Digits_2004      -0.27518025   1.331131405   9.4171447   2.510843415  3.1579402
## LFLU_2004        -0.39788082   2.417781727   2.5108434  18.940356324  8.9280685
## CFLU_2004        -0.69912265   3.346110301   3.1579402   8.928068528 37.7541443
## Simil_2011       -0.35911053   3.044747455   1.0520110   2.057132210  3.3285151
## Digits_2011      -0.27213994   1.006587351   2.7628833   2.397620286  3.6799624
## LFLU_2011        -0.45159790   2.327008014   2.4643644  10.640388029  7.8602722
## CFLU_2011        -0.72534182   2.993916532   3.2001397   7.657133909 21.2654822
## TotRecall_2004   -0.18851395   1.079735337   3.3745014   2.786483399  4.5382462
## TotRecall_2011   -0.35737180   1.560607296   1.8921297   2.533224810  4.6626632
## N_04             -0.01758030   0.326925741   0.0342083   0.006641092  0.1769225
## N_11             -0.02399269   0.474910026   0.2028156   0.534026595  1.1804908
##                   Simil_2011  Digits_2011    LFLU_2011     CFLU_2011
## idpub          -104.51299459 488.25712449 417.53854430 1299.24434526
## sexrsp           -0.02257908   0.05818348   0.28405780    0.48956358
## byear             0.16913832   0.15718613   0.27022839    0.37530786
## educ92            2.06106307   1.10982916   2.42386590    2.80755167
## age04            -0.20976724  -0.23940734  -0.33441980   -0.35986359
## age11            -0.35911053  -0.27213994  -0.45159790   -0.72534182
## Simil_2004        3.04474746   1.00658735   2.32700801    2.99391653
## Digits_2004       1.05201099   2.76288333   2.46436444    3.20013968
## LFLU_2004         2.05713221   2.39762029  10.64038803    7.65713391
## CFLU_2004         3.32851511   3.67996243   7.86027219   21.26548220
## Simil_2011        5.38484411   1.27168624   2.39948407    3.32311370
## Digits_2011       1.27168624   6.90268988   2.97387346    4.17310228
## LFLU_2011         2.39948407   2.97387346  17.48801731    8.68513275
## CFLU_2011         3.32311370   4.17310228   8.68513275   35.66045150
## TotRecall_2004    0.91983711   1.38864206   2.91433472    4.48433010
## TotRecall_2011    1.77304168   1.95105453   3.09111418    5.19984001
## N_04              0.12770595   0.03941887   0.13575019    0.08632917
## N_11              0.10314379   0.07616021   0.05187397    0.11475618
##                TotRecall_2004 TotRecall_2011          N_04          N_11
## idpub              93.9178875   301.35513526 -2.725737e+02 -1.097166e+02
## sexrsp              0.4670797     0.34329518  5.649397e-03 -1.767563e-03
## byear               0.1723557     0.23389400  2.319806e-02  3.396987e-02
## educ92              1.1651182     1.13429372  5.320233e-02  3.281137e-01
## age04              -0.1941360    -0.27067073 -5.976023e-02 -8.894501e-02
## age11              -0.1885139    -0.35737180 -1.758030e-02 -2.399269e-02
## Simil_2004          1.0797353     1.56060730  3.269257e-01  4.749100e-01
## Digits_2004         3.3745014     1.89212967  3.420830e-02  2.028156e-01
## LFLU_2004           2.7864834     2.53322481  6.641092e-03  5.340266e-01
## CFLU_2004           4.5382462     4.66266321  1.769225e-01  1.180491e+00
## Simil_2011          0.9198371     1.77304168  1.277060e-01  1.031438e-01
## Digits_2011         1.3886421     1.95105453  3.941887e-02  7.616021e-02
## LFLU_2011           2.9143347     3.09111418  1.357502e-01  5.187397e-02
## CFLU_2011           4.4843301     5.19984001  8.632917e-02  1.147562e-01
## TotRecall_2004     13.4775018     3.78005292  1.117288e-01  2.353521e-01
## TotRecall_2011      3.7800529     8.44096701  4.875749e-02  6.984301e-02
## N_04                0.1117288     0.04875749  1.477595e+00  7.089121e-01
## N_11                0.2353521     0.06984301  7.089121e-01  2.350591e+00
model.CI <- '
#Latent variables
CogT1 =~ NA*Simil_2004 + a*Simil_2004 + Digits_2004 + LFLU_2004 + CFLU_2004
CogT2 =~ NA*Simil_2011 + a*Simil_2011 + Digits_2011 + LFLU_2011 + CFLU_2011

# Residuals
Simil_2004 ~~ Simil_2004
Simil_2011 ~~ Simil_2011
Digits_2004 ~~ Digits_2004
Digits_2011 ~~ Digits_2011
LFLU_2004 ~~ LFLU_2004
LFLU_2011 ~~ LFLU_2011
CFLU_2004 ~~ CFLU_2004
CFLU_2011 ~~ CFLU_2011

# Residual covariances
Simil_2004 ~~ Simil_2011
Digits_2004 ~~ Digits_2011
LFLU_2004 ~~ LFLU_2011
CFLU_2004 ~~ CFLU_2011

# Intercepts
Simil_2004 ~ nu1*1
Simil_2011 ~ nu1*1
Digits_2004 ~ nu12*1
Digits_2011 ~ nu22*1
LFLU_2004 ~ nu13*1
LFLU_2011 ~ nu23*1
CFLU_2004 ~ nu14*1
CFLU_2011 ~ nu24*1

#Latent variances/covariances
#Standardized CogT1
CogT1 ~~ 1*CogT1
#covariance
CogT2 ~~ cov*CogT1
#variance Time 2
CogT2 ~~ NA*CogT2

#Latent means
CogT1 ~ a1*1
CogT2 ~ a2*1
a1 == 0
'

model.CI.fit <- sem(model.CI, data=HW2_TimeData, missing = "FIML")
model.CI.fit
## lavaan 0.6.15 ended normally after 107 iterations
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                        32
##   Number of equality constraints                     3
## 
##   Number of observations                          7078
##   Number of missing patterns                        75
## 
## Model Test User Model:
##                                                       
##   Test statistic                                28.999
##   Degrees of freedom                                15
##   P-value (Chi-square)                           0.016
summary(model.CI.fit, fit.measures = TRUE, standardized = T)
## lavaan 0.6.15 ended normally after 107 iterations
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                        32
##   Number of equality constraints                     3
## 
##   Number of observations                          7078
##   Number of missing patterns                        75
## 
## Model Test User Model:
##                                                       
##   Test statistic                                28.999
##   Degrees of freedom                                15
##   P-value (Chi-square)                           0.016
## 
## Model Test Baseline Model:
## 
##   Test statistic                              7086.446
##   Degrees of freedom                                28
##   P-value                                        0.000
## 
## User Model versus Baseline Model:
## 
##   Comparative Fit Index (CFI)                    0.998
##   Tucker-Lewis Index (TLI)                       0.996
##                                                       
##   Robust Comparative Fit Index (CFI)             0.998
##   Robust Tucker-Lewis Index (TLI)                0.996
## 
## Loglikelihood and Information Criteria:
## 
##   Loglikelihood user model (H0)             -95272.349
##   Loglikelihood unrestricted model (H1)     -95257.849
##                                                       
##   Akaike (AIC)                              190602.698
##   Bayesian (BIC)                            190801.775
##   Sample-size adjusted Bayesian (SABIC)     190709.620
## 
## Root Mean Square Error of Approximation:
## 
##   RMSEA                                          0.011
##   90 Percent confidence interval - lower         0.005
##   90 Percent confidence interval - upper         0.018
##   P-value H_0: RMSEA <= 0.050                    1.000
##   P-value H_0: RMSEA >= 0.080                    0.000
##                                                       
##   Robust RMSEA                                   0.016
##   90 Percent confidence interval - lower         0.004
##   90 Percent confidence interval - upper         0.026
##   P-value H_0: Robust RMSEA <= 0.050             1.000
##   P-value H_0: Robust RMSEA >= 0.080             0.000
## 
## Standardized Root Mean Square Residual:
## 
##   SRMR                                           0.010
## 
## Parameter Estimates:
## 
##   Standard errors                             Standard
##   Information                                 Observed
##   Observed information based on                Hessian
## 
## Latent Variables:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##   CogT1 =~                                                              
##     Simil_2004 (a)    1.059    0.041   25.767    0.000    1.059    0.445
##     Digts_2004        1.105    0.057   19.421    0.000    1.105    0.360
##     LFLU_2004         2.491    0.086   28.845    0.000    2.491    0.570
##     CFLU_2004         3.496    0.138   25.380    0.000    3.496    0.568
##   CogT2 =~                                                              
##     Simil_2011 (a)    1.059    0.041   25.767    0.000    1.021    0.439
##     Digts_2011        1.252    0.073   17.163    0.000    1.207    0.458
##     LFLU_2011         2.700    0.142   19.020    0.000    2.604    0.620
##     CFLU_2011         3.600    0.205   17.582    0.000    3.472    0.578
## 
## Covariances:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##  .Simil_2004 ~~                                                         
##    .Sml_2011          2.117    0.082   25.680    0.000    2.117    0.475
##  .Digits_2004 ~~                                                        
##    .Dgt_2011          1.658    0.125   13.276    0.000    1.658    0.247
##  .LFLU_2004 ~~                                                          
##    .LFLU_201          5.098    0.328   15.523    0.000    5.098    0.431
##  .CFLU_2004 ~~                                                          
##    .CFLU_201         11.024    0.750   14.698    0.000   11.024    0.444
##   CogT1 ~~                                                              
##     CogT2    (cov)    0.883    0.039   22.402    0.000    0.915    0.915
## 
## Intercepts:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Sm_2004  (nu1)    6.577    0.029  229.089    0.000    6.577    2.763
##    .Sm_2011  (nu1)    6.577    0.029  229.089    0.000    6.577    2.827
##    .Dg_2004 (nu12)    7.197    0.042  171.902    0.000    7.197    2.344
##    .Dg_2011 (nu22)    7.086    0.055  129.049    0.000    7.086    2.690
##    .LFLU_20 (nu13)   11.327    0.059  190.461    0.000   11.327    2.592
##    .LFLU_20 (nu23)   11.782    0.100  117.506    0.000   11.782    2.804
##    .CFLU_20 (nu14)   20.782    0.103  201.946    0.000   20.782    3.376
##    .CFLU_20 (nu24)   20.306    0.155  130.890    0.000   20.306    3.381
##     CogT1     (a1)    0.000                               0.000    0.000
##     CogT2     (a2)   -0.281    0.030   -9.391    0.000   -0.292   -0.292
## 
## Variances:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Simil_2004        4.543    0.102   44.745    0.000    4.543    0.802
##    .Simil_2011        4.371    0.103   42.293    0.000    4.371    0.807
##    .Digits_2004       8.207    0.181   45.225    0.000    8.207    0.871
##    .Digits_2011       5.483    0.145   37.705    0.000    5.483    0.790
##    .LFLU_2004        12.890    0.414   31.121    0.000   12.890    0.675
##    .LFLU_2011        10.878    0.397   27.434    0.000   10.878    0.616
##    .CFLU_2004        25.668    0.922   27.830    0.000   25.668    0.677
##    .CFLU_2011        24.018    0.937   25.621    0.000   24.018    0.666
##     CogT1             1.000                               1.000    1.000
##     CogT2             0.930    0.075   12.335    0.000    1.000    1.000
## 
## Constraints:
##                                                |Slack|
##     a1 - 0                                       0.000
semPaths(model.CI.fit, what = "est") #Configural invariance model. Equate 1 set of lambdas/loadings for Simil_2004 and Simil_2011 ("a") and one set of intercepts ("nu1"). Latent variables include Cog_T1 (cognitive function at T1) amd Cog_T2 (cognitive function at T2). Observed variables include Simil_2004 (WAIS similarities at T1), Digits_2004 (digital ordering at T1), LFLU_2004 (letter fluency at T1), CFLU_2004 (category fluency at T1), Simil_2011 (WAIS similarities at T2), Digits_2011 (digital ordering at T2), LFLU_2011 (letter fluency at T2), and CFLU_2011 (category fluency at T2). All of the tested models had high χ2 values and the corresponding p-values were highly significant. Because χ2 is sensitive to sample size, other fit indices were considered in order to determine model fit. Both the configural invariance model and weak invariance model achieved excellent fit (CFI and TLI >.95; RMSEA < .06).

model.WI <- '
#Latent variables
CogT1 =~ NA*Simil_2004 + a*Simil_2004 + b*Digits_2004 + c*LFLU_2004 + d*CFLU_2004
CogT2 =~ NA*Simil_2011 + a*Simil_2011 + b*Digits_2011 + c*LFLU_2011 + d*CFLU_2011

# Residuals
Simil_2004 ~~ Simil_2004
Simil_2011 ~~ Simil_2011
Digits_2004 ~~ Digits_2004
Digits_2011 ~~ Digits_2011
LFLU_2004 ~~ LFLU_2004
LFLU_2011 ~~ LFLU_2011
CFLU_2004 ~~ CFLU_2004
CFLU_2011 ~~ CFLU_2011

# Residual covariances
Simil_2004 ~~ Simil_2011
Digits_2004 ~~ Digits_2011
LFLU_2004 ~~ LFLU_2011
CFLU_2004 ~~ CFLU_2011

# Intercepts
Simil_2004 ~ nu1*1
Simil_2011 ~ nu1*1
Digits_2004 ~ nu12*1
Digits_2011 ~ nu22*1
LFLU_2004 ~ nu13*1
LFLU_2011 ~ nu23*1
CFLU_2004 ~ nu14*1
CFLU_2011 ~ nu24*1

#Latent variances/covariances
#Standardized CogT1
CogT1 ~~ 1*CogT1
#covariance
CogT2 ~~ cov*CogT1
#variance Time 2
CogT2 ~~ NA*CogT2

#Latent means
CogT1 ~ a1*1
CogT2 ~ a2*1
a1 == 0
'

model.WI.fit <- sem(model.WI, data=HW2_TimeData, missing = "FIML")
model.WI.fit
## lavaan 0.6.15 ended normally after 92 iterations
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                        32
##   Number of equality constraints                     6
## 
##   Number of observations                          7078
##   Number of missing patterns                        75
## 
## Model Test User Model:
##                                                       
##   Test statistic                                33.392
##   Degrees of freedom                                18
##   P-value (Chi-square)                           0.015
summary(model.WI.fit, fit.measures = TRUE, standardized = T)
## lavaan 0.6.15 ended normally after 92 iterations
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                        32
##   Number of equality constraints                     6
## 
##   Number of observations                          7078
##   Number of missing patterns                        75
## 
## Model Test User Model:
##                                                       
##   Test statistic                                33.392
##   Degrees of freedom                                18
##   P-value (Chi-square)                           0.015
## 
## Model Test Baseline Model:
## 
##   Test statistic                              7086.446
##   Degrees of freedom                                28
##   P-value                                        0.000
## 
## User Model versus Baseline Model:
## 
##   Comparative Fit Index (CFI)                    0.998
##   Tucker-Lewis Index (TLI)                       0.997
##                                                       
##   Robust Comparative Fit Index (CFI)             0.998
##   Robust Tucker-Lewis Index (TLI)                0.997
## 
## Loglikelihood and Information Criteria:
## 
##   Loglikelihood user model (H0)             -95274.545
##   Loglikelihood unrestricted model (H1)     -95257.849
##                                                       
##   Akaike (AIC)                              190601.091
##   Bayesian (BIC)                            190779.574
##   Sample-size adjusted Bayesian (SABIC)     190696.952
## 
## Root Mean Square Error of Approximation:
## 
##   RMSEA                                          0.011
##   90 Percent confidence interval - lower         0.005
##   90 Percent confidence interval - upper         0.017
##   P-value H_0: RMSEA <= 0.050                    1.000
##   P-value H_0: RMSEA >= 0.080                    0.000
##                                                       
##   Robust RMSEA                                   0.015
##   90 Percent confidence interval - lower         0.003
##   90 Percent confidence interval - upper         0.024
##   P-value H_0: Robust RMSEA <= 0.050             1.000
##   P-value H_0: Robust RMSEA >= 0.080             0.000
## 
## Standardized Root Mean Square Residual:
## 
##   SRMR                                           0.012
## 
## Parameter Estimates:
## 
##   Standard errors                             Standard
##   Information                                 Observed
##   Observed information based on                Hessian
## 
## Latent Variables:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##   CogT1 =~                                                              
##     Simil_2004 (a)    1.034    0.038   27.566    0.000    1.034    0.435
##     Digts_2004 (b)    1.153    0.044   26.035    0.000    1.153    0.374
##     LFLU_2004  (c)    2.526    0.077   32.628    0.000    2.526    0.577
##     CFLU_2004  (d)    3.457    0.123   28.184    0.000    3.457    0.563
##   CogT2 =~                                                              
##     Simil_2011 (a)    1.034    0.038   27.566    0.000    1.051    0.450
##     Digts_2011 (b)    1.153    0.044   26.035    0.000    1.172    0.446
##     LFLU_2011  (c)    2.526    0.077   32.628    0.000    2.567    0.612
##     CFLU_2011  (d)    3.457    0.123   28.184    0.000    3.513    0.584
## 
## Covariances:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##  .Simil_2004 ~~                                                         
##    .Sml_2011          2.113    0.083   25.584    0.000    2.113    0.474
##  .Digits_2004 ~~                                                        
##    .Dgt_2011          1.649    0.125   13.223    0.000    1.649    0.246
##  .LFLU_2004 ~~                                                          
##    .LFLU_201          5.101    0.329   15.525    0.000    5.101    0.430
##  .CFLU_2004 ~~                                                          
##    .CFLU_201         11.011    0.750   14.682    0.000   11.011    0.443
##   CogT1 ~~                                                              
##     CogT2    (cov)    0.932    0.025   37.366    0.000    0.917    0.917
## 
## Intercepts:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Sm_2004  (nu1)    6.577    0.029  229.588    0.000    6.577    2.770
##    .Sm_2011  (nu1)    6.577    0.029  229.588    0.000    6.577    2.819
##    .Dg_2004 (nu12)    7.196    0.042  171.458    0.000    7.196    2.336
##    .Dg_2011 (nu22)    7.070    0.053  134.534    0.000    7.070    2.693
##    .LFLU_20 (nu13)   11.327    0.060  190.161    0.000   11.327    2.586
##    .LFLU_20 (nu23)   11.756    0.095  123.203    0.000   11.756    2.803
##    .CFLU_20 (nu14)   20.786    0.103  202.173    0.000   20.786    3.383
##    .CFLU_20 (nu24)   20.292    0.152  133.925    0.000   20.292    3.371
##     CogT1     (a1)    0.000       NA                      0.000    0.000
##     CogT2     (a2)   -0.289    0.030   -9.544    0.000   -0.285   -0.285
## 
## Variances:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Simil_2004        4.571    0.099   46.015    0.000    4.571    0.810
##    .Simil_2011        4.340    0.102   42.628    0.000    4.340    0.797
##    .Digits_2004       8.158    0.177   45.969    0.000    8.158    0.860
##    .Digits_2011       5.520    0.143   38.626    0.000    5.520    0.801
##    .LFLU_2004        12.796    0.402   31.810    0.000   12.796    0.667
##    .LFLU_2011        11.001    0.380   28.968    0.000   11.001    0.625
##    .CFLU_2004        25.811    0.891   28.954    0.000   25.811    0.684
##    .CFLU_2011        23.884    0.916   26.060    0.000   23.884    0.659
##     CogT1             1.000                               1.000    1.000
##     CogT2             1.033    0.043   24.023    0.000    1.000    1.000
## 
## Constraints:
##                                                |Slack|
##     a1 - 0                                       0.000
semPaths(model.WI.fit, what = "est") #Weak invariance model. Equate all loadings/lambdas ("a", "b", "c", and "d") and one set of intercepts ("nu1"). All of the tested models had high χ2 values and the corresponding p-values were highly significant. Because χ2 is sensitive to sample size, other fit indices were considered in order to determine model fit. Both the configural invariance model and weak invariance model achieved excellent fit (CFI and TLI >.95; RMSEA < .06). In addition, there was no significant worsening of fit when moving from the configural to the weak model (Δχ2 = 4.39, p = .22). 

model.SI <- '
#Latent variables
CogT1 =~ NA*Simil_2004 + a*Simil_2004 + b*Digits_2004 + c*LFLU_2004 + d*CFLU_2004
CogT2 =~ NA*Simil_2011 + a*Simil_2011 + b*Digits_2011 + c*LFLU_2011 + d*CFLU_2011

# Residuals
Simil_2004 ~~ Simil_2004
Simil_2011 ~~ Simil_2011
Digits_2004 ~~ Digits_2004
Digits_2011 ~~ Digits_2011
LFLU_2004 ~~ LFLU_2004
LFLU_2011 ~~ LFLU_2011
CFLU_2004 ~~ CFLU_2004
CFLU_2011 ~~ CFLU_2011

# Residual covariances
Simil_2004 ~~ Simil_2011
Digits_2004 ~~ Digits_2011
LFLU_2004 ~~ LFLU_2011
CFLU_2004 ~~ CFLU_2011

# Intercepts
Simil_2004 ~ nu1*1
Simil_2011 ~ nu1*1
Digits_2004 ~ nu2*1
Digits_2011 ~ nu2*1
LFLU_2004 ~ nu3*1
LFLU_2011 ~ nu3*1
CFLU_2004 ~ nu4*1
CFLU_2011 ~ nu4*1

#Latent variances/covariances
#Standardized CogT1
CogT1 ~~ 1*CogT1
#covariance
CogT2 ~~ cov*CogT1
#variance Time 2
CogT2 ~~ NA*CogT2

#Latent means
CogT1 ~ a1*1
CogT2 ~ a2*1
a1 == 0
'

model.SI.fit <- sem(model.SI, data=HW2_TimeData, missing = "FIML")
model.SI.fit
## lavaan 0.6.15 ended normally after 87 iterations
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                        32
##   Number of equality constraints                     9
## 
##   Number of observations                          7078
##   Number of missing patterns                        75
## 
## Model Test User Model:
##                                                       
##   Test statistic                               109.972
##   Degrees of freedom                                21
##   P-value (Chi-square)                           0.000
summary(model.SI.fit, fit.measures = TRUE, standardized = T)
## lavaan 0.6.15 ended normally after 87 iterations
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                        32
##   Number of equality constraints                     9
## 
##   Number of observations                          7078
##   Number of missing patterns                        75
## 
## Model Test User Model:
##                                                       
##   Test statistic                               109.972
##   Degrees of freedom                                21
##   P-value (Chi-square)                           0.000
## 
## Model Test Baseline Model:
## 
##   Test statistic                              7086.446
##   Degrees of freedom                                28
##   P-value                                        0.000
## 
## User Model versus Baseline Model:
## 
##   Comparative Fit Index (CFI)                    0.987
##   Tucker-Lewis Index (TLI)                       0.983
##                                                       
##   Robust Comparative Fit Index (CFI)             0.987
##   Robust Tucker-Lewis Index (TLI)                0.983
## 
## Loglikelihood and Information Criteria:
## 
##   Loglikelihood user model (H0)             -95312.835
##   Loglikelihood unrestricted model (H1)     -95257.849
##                                                       
##   Akaike (AIC)                              190671.670
##   Bayesian (BIC)                            190829.560
##   Sample-size adjusted Bayesian (SABIC)     190756.471
## 
## Root Mean Square Error of Approximation:
## 
##   RMSEA                                          0.024
##   90 Percent confidence interval - lower         0.020
##   90 Percent confidence interval - upper         0.029
##   P-value H_0: RMSEA <= 0.050                    1.000
##   P-value H_0: RMSEA >= 0.080                    0.000
##                                                       
##   Robust RMSEA                                   0.034
##   90 Percent confidence interval - lower         0.028
##   90 Percent confidence interval - upper         0.041
##   P-value H_0: Robust RMSEA <= 0.050             1.000
##   P-value H_0: Robust RMSEA >= 0.080             0.000
## 
## Standardized Root Mean Square Residual:
## 
##   SRMR                                           0.021
## 
## Parameter Estimates:
## 
##   Standard errors                             Standard
##   Information                                 Observed
##   Observed information based on                Hessian
## 
## Latent Variables:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##   CogT1 =~                                                              
##     Simil_2004 (a)    1.046    0.036   28.741    0.000    1.046    0.440
##     Digts_2004 (b)    1.182    0.044   27.108    0.000    1.182    0.383
##     LFLU_2004  (c)    2.361    0.074   31.954    0.000    2.361    0.542
##     CFLU_2004  (d)    3.624    0.120   30.146    0.000    3.624    0.586
##   CogT2 =~                                                              
##     Simil_2011 (a)    1.046    0.036   28.741    0.000    1.069    0.458
##     Digts_2011 (b)    1.182    0.044   27.108    0.000    1.208    0.459
##     LFLU_2011  (c)    2.361    0.074   31.954    0.000    2.412    0.578
##     CFLU_2011  (d)    3.624    0.120   30.146    0.000    3.704    0.610
## 
## Covariances:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##  .Simil_2004 ~~                                                         
##    .Sml_2011          2.084    0.082   25.493    0.000    2.084    0.471
##  .Digits_2004 ~~                                                        
##    .Dgt_2011          1.599    0.124   12.852    0.000    1.599    0.240
##  .LFLU_2004 ~~                                                          
##    .LFLU_201          5.563    0.314   17.693    0.000    5.563    0.446
##  .CFLU_2004 ~~                                                          
##    .CFLU_201         10.176    0.746   13.633    0.000   10.176    0.422
##   CogT1 ~~                                                              
##     CogT2    (cov)    0.941    0.025   37.130    0.000    0.920    0.920
## 
## Intercepts:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Sml_2004 (nu1)    6.572    0.027  245.557    0.000    6.572    2.766
##    .Sml_2011 (nu1)    6.572    0.027  245.557    0.000    6.572    2.816
##    .Dgt_2004 (nu2)    7.124    0.035  205.432    0.000    7.124    2.309
##    .Dgt_2011 (nu2)    7.124    0.035  205.432    0.000    7.124    2.706
##    .LFLU_200 (nu3)   11.528    0.054  214.558    0.000   11.528    2.648
##    .LFLU_201 (nu3)   11.528    0.054  214.558    0.000   11.528    2.761
##    .CFLU_200 (nu4)   20.567    0.096  213.699    0.000   20.567    3.323
##    .CFLU_201 (nu4)   20.567    0.096  213.699    0.000   20.567    3.389
##     CogT1     (a1)    0.000                               0.000    0.000
##     CogT2     (a2)   -0.275    0.017  -16.088    0.000   -0.269   -0.269
## 
## Variances:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Simil_2004        4.550    0.099   45.980    0.000    4.550    0.806
##    .Simil_2011        4.304    0.101   42.642    0.000    4.304    0.790
##    .Digits_2004       8.126    0.178   45.630    0.000    8.126    0.853
##    .Digits_2011       5.472    0.143   38.216    0.000    5.472    0.790
##    .LFLU_2004        13.387    0.383   34.915    0.000   13.387    0.706
##    .LFLU_2011        11.608    0.361   32.174    0.000   11.608    0.666
##    .CFLU_2004        25.170    0.903   27.881    0.000   25.170    0.657
##    .CFLU_2011        23.105    0.923   25.044    0.000   23.105    0.627
##     CogT1             1.000                               1.000    1.000
##     CogT2             1.045    0.044   23.829    0.000    1.000    1.000
## 
## Constraints:
##                                                |Slack|
##     a1 - 0                                       0.000
semPaths(model.SI.fit, what = "est") #Strong invariance model. Equate all loadings/lambdas ("a", "b", "c", and "d") and intercepts ("nu1", "nu2", "nu3", and "nu4"). When further constraining the weak invariance model to the strong invariance model the fit significantly worsened (Δχ2 = 76.58, p < .001). However, the strong invariance model still demonstrated excellent fit indices (CFI and TLI >.95; RMSEA < .06), thus strong invariance measurement was achieved.

model.STI <- '
#Latent variables
CogT1 =~ NA*Simil_2004 + a*Simil_2004 + b*Digits_2004 + c*LFLU_2004 + d*CFLU_2004
CogT2 =~ NA*Simil_2011 + a*Simil_2011 + b*Digits_2011 + c*LFLU_2011 + d*CFLU_2011

# Residuals
Simil_2004 ~~ f*Simil_2004
Simil_2011 ~~ f*Simil_2011
Digits_2004 ~~ g*Digits_2004
Digits_2011 ~~ g*Digits_2011
LFLU_2004 ~~ h*LFLU_2004
LFLU_2011 ~~ h*LFLU_2011
CFLU_2004 ~~ i*CFLU_2004
CFLU_2011 ~~ i*CFLU_2011

# Residual covariances
Simil_2004 ~~ Simil_2011
Digits_2004 ~~ Digits_2011
LFLU_2004 ~~ LFLU_2011
CFLU_2004 ~~ CFLU_2011

# Intercepts
Simil_2004 ~ nu1*1
Simil_2011 ~ nu1*1
Digits_2004 ~ nu2*1
Digits_2011 ~ nu2*1
LFLU_2004 ~ nu3*1
LFLU_2011 ~ nu3*1
CFLU_2004 ~ nu4*1
CFLU_2011 ~ nu4*1

#Latent variances/covariances
#Standardized CogT1
CogT1 ~~ 1*CogT1
#covariance
CogT2 ~~ cov*CogT1
#variance Time 2
CogT2 ~~ NA*CogT2

#Latent means
CogT1 ~ a1*1
CogT2 ~ a2*1
a1 == 0
'

model.STI.fit <- sem(model.STI, data=HW2_TimeData, missing = "FIML")
model.STI.fit
## lavaan 0.6.15 ended normally after 75 iterations
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                        32
##   Number of equality constraints                    13
## 
##   Number of observations                          7078
##   Number of missing patterns                        75
## 
## Model Test User Model:
##                                                       
##   Test statistic                               291.616
##   Degrees of freedom                                25
##   P-value (Chi-square)                           0.000
summary(model.STI.fit, fit.measures = TRUE, standardized = T)
## lavaan 0.6.15 ended normally after 75 iterations
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                        32
##   Number of equality constraints                    13
## 
##   Number of observations                          7078
##   Number of missing patterns                        75
## 
## Model Test User Model:
##                                                       
##   Test statistic                               291.616
##   Degrees of freedom                                25
##   P-value (Chi-square)                           0.000
## 
## Model Test Baseline Model:
## 
##   Test statistic                              7086.446
##   Degrees of freedom                                28
##   P-value                                        0.000
## 
## User Model versus Baseline Model:
## 
##   Comparative Fit Index (CFI)                    0.962
##   Tucker-Lewis Index (TLI)                       0.958
##                                                       
##   Robust Comparative Fit Index (CFI)             0.965
##   Robust Tucker-Lewis Index (TLI)                0.961
## 
## Loglikelihood and Information Criteria:
## 
##   Loglikelihood user model (H0)             -95403.657
##   Loglikelihood unrestricted model (H1)     -95257.849
##                                                       
##   Akaike (AIC)                              190845.314
##   Bayesian (BIC)                            190975.744
##   Sample-size adjusted Bayesian (SABIC)     190915.367
## 
## Root Mean Square Error of Approximation:
## 
##   RMSEA                                          0.039
##   90 Percent confidence interval - lower         0.035
##   90 Percent confidence interval - upper         0.043
##   P-value H_0: RMSEA <= 0.050                    1.000
##   P-value H_0: RMSEA >= 0.080                    0.000
##                                                       
##   Robust RMSEA                                   0.052
##   90 Percent confidence interval - lower         0.046
##   90 Percent confidence interval - upper         0.058
##   P-value H_0: Robust RMSEA <= 0.050             0.280
##   P-value H_0: Robust RMSEA >= 0.080             0.000
## 
## Standardized Root Mean Square Residual:
## 
##   SRMR                                           0.041
## 
## Parameter Estimates:
## 
##   Standard errors                             Standard
##   Information                                 Observed
##   Observed information based on                Hessian
## 
## Latent Variables:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##   CogT1 =~                                                              
##     Simil_2004 (a)    1.091    0.037   29.821    0.000    1.091    0.461
##     Digts_2004 (b)    1.208    0.046   26.532    0.000    1.208    0.416
##     LFLU_2004  (c)    2.425    0.075   32.527    0.000    2.425    0.565
##     CFLU_2004  (d)    3.703    0.121   30.602    0.000    3.703    0.599
##   CogT2 =~                                                              
##     Simil_2011 (a)    1.091    0.037   29.821    0.000    1.046    0.446
##     Digts_2011 (b)    1.208    0.046   26.532    0.000    1.158    0.402
##     LFLU_2011  (c)    2.425    0.075   32.527    0.000    2.324    0.549
##     CFLU_2011  (d)    3.703    0.121   30.602    0.000    3.549    0.583
## 
## Covariances:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##  .Simil_2004 ~~                                                         
##    .Sml_2011          2.069    0.083   25.044    0.000    2.069    0.469
##  .Digits_2004 ~~                                                        
##    .Dgt_2011          1.702    0.131   12.992    0.000    1.702    0.244
##  .LFLU_2004 ~~                                                          
##    .LFLU_201          5.569    0.318   17.540    0.000    5.569    0.444
##  .CFLU_2004 ~~                                                          
##    .CFLU_201         10.412    0.754   13.816    0.000   10.412    0.426
##   CogT1 ~~                                                              
##     CogT2    (cov)    0.885    0.022   40.260    0.000    0.923    0.923
## 
## Intercepts:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Sml_2004 (nu1)    6.572    0.027  244.621    0.000    6.572    2.776
##    .Sml_2011 (nu1)    6.572    0.027  244.621    0.000    6.572    2.801
##    .Dgt_2004 (nu2)    7.136    0.035  206.075    0.000    7.136    2.459
##    .Dgt_2011 (nu2)    7.136    0.035  206.075    0.000    7.136    2.476
##    .LFLU_200 (nu3)   11.504    0.054  214.995    0.000   11.504    2.681
##    .LFLU_201 (nu3)   11.504    0.054  214.995    0.000   11.504    2.716
##    .CFLU_200 (nu4)   20.573    0.096  213.681    0.000   20.573    3.331
##    .CFLU_201 (nu4)   20.573    0.096  213.681    0.000   20.573    3.380
##     CogT1     (a1)    0.000                               0.000    0.000
##     CogT2     (a2)   -0.264    0.016  -16.084    0.000   -0.276   -0.276
## 
## Variances:
##                    Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
##    .Simil_2004 (f)    4.414    0.083   53.253    0.000    4.414    0.788
##    .Simil_2011 (f)    4.414    0.083   53.253    0.000    4.414    0.801
##    .Digts_2004 (g)    6.966    0.126   55.373    0.000    6.966    0.827
##    .Digts_2011 (g)    6.966    0.126   55.373    0.000    6.966    0.839
##    .LFLU_2004  (h)   12.534    0.314   39.936    0.000   12.534    0.681
##    .LFLU_2011  (h)   12.534    0.314   39.936    0.000   12.534    0.699
##    .CFLU_2004  (i)   24.448    0.762   32.101    0.000   24.448    0.641
##    .CFLU_2011  (i)   24.448    0.762   32.101    0.000   24.448    0.660
##     CogT1             1.000                               1.000    1.000
##     CogT2             0.919    0.036   25.423    0.000    1.000    1.000
## 
## Constraints:
##                                                |Slack|
##     a1 - 0                                       0.000
semPaths(model.STI.fit, what = "est") #Strict invariance model. Equate all loadings/lambdas ("a", "b", "c", and "d"), intercepts ("nu1", "nu2", "nu3", and "nu4"), and residuals ("f", "g", "h", and "i"). In addition, when further constraining the strong invariance model to the strict invariance model the fit significantly worsened (Δχ2 = 181.64, p < .001). However, the strict invariance model still demonstrated excellent fit indices (CFI and TLI >.95; RMSEA < .06). 

Mod.Fit.Comp <- compareFit(model.CI.fit, model.WI.fit, model.SI.fit, model.STI.fit)
summary(Mod.Fit.Comp) #fit comparisons across models. Based on these nested model comparisons, strict invariance measurement was established, thus latent changes in cognitive functioning between timepoint 1 and timepoint 2 cannot be assumed to be because of measurement error. Given that at time point 2 the standardized latent mean score was -.26 with a variance of .92, it can be concluded that there was a slight decrease in overall cognitive functioning over time. In summary, despite the strict invariance model not being the best-fitting model in comparison to the configural invariance model, weak invariance model, and strong invariance model, the fit indices were still excellent, thus it can be determined that overall cognitive functioning was measured at both time points. 
## ################### Nested Model Comparison #########################
## 
## Chi-Squared Difference Test
## 
##               Df    AIC    BIC   Chisq Chisq diff    RMSEA Df diff Pr(>Chisq)
## model.CI.fit  15 190603 190802  28.999                                       
## model.WI.fit  18 190601 190780  33.392      4.393 0.008100       3      0.222
## model.SI.fit  21 190672 190830 109.972     76.580 0.058866       3     <2e-16
## model.STI.fit 25 190845 190976 291.616    181.644 0.079212       4     <2e-16
##                  
## model.CI.fit     
## model.WI.fit     
## model.SI.fit  ***
## model.STI.fit ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## ####################### Model Fit Indices ###########################
##                  chisq df pvalue rmsea    cfi    tli  srmr         aic
## model.CI.fit   28.999† 15   .016 .011  0.998† 0.996  .010† 190602.698 
## model.WI.fit   33.392  18   .015 .011† 0.998  0.997† .012  190601.091†
## model.SI.fit  109.972  21   .000 .024   .987   .983  .021  190671.670 
## model.STI.fit 291.616  25   .000 .039   .962   .958  .041  190845.314 
##                       bic
## model.CI.fit  190801.775 
## model.WI.fit  190779.574†
## model.SI.fit  190829.560 
## model.STI.fit 190975.744 
## 
## ################## Differences in Fit Indices #######################
##                              df rmsea    cfi    tli  srmr     aic     bic
## model.WI.fit - model.CI.fit   3 0.000  0.000  0.000 0.001  -1.607 -22.201
## model.SI.fit - model.WI.fit   3 0.013 -0.010 -0.013 0.009  70.580  49.985
## model.STI.fit - model.SI.fit  4 0.014 -0.025 -0.025 0.020 173.644 146.185
CI.Conf <- CI.RMSEA(rmsea = .011, df = 15, N=7078, clevel = .95)
CI.Conf
## $Lower.CI
## [1] 0.00135613
## 
## $RMSEA
## [1] 0.011
## 
## $Upper.CI
## [1] 0.01837454
CI.Weak <- CI.RMSEA(rmsea = .011, df = 18, N=7078, clevel = .95)
CI.Weak
## $Lower.CI
## [1] 0.00293246
## 
## $RMSEA
## [1] 0.011
## 
## $Upper.CI
## [1] 0.0177394
CI.Strong <- CI.RMSEA(rmsea = .024, df = 21, N=7078, clevel = .95)
CI.Strong
## $Lower.CI
## [1] 0.01871014
## 
## $RMSEA
## [1] 0.024
## 
## $Upper.CI
## [1] 0.02946891
CI.Strict <- CI.RMSEA(rmsea = .039, df = 25, N=7078, clevel = .95)
CI.Strict #confidence intervals for each model 
## $Lower.CI
## [1] 0.03429982
## 
## $RMSEA
## [1] 0.039
## 
## $Upper.CI
## [1] 0.04382587
sessionInfo() #Retrieving session information
## R version 4.2.2 (2022-10-31)
## Platform: aarch64-apple-darwin20 (64-bit)
## Running under: macOS Ventura 13.2.1
## 
## Matrix products: default
## BLAS:   /Library/Frameworks/R.framework/Versions/4.2-arm64/Resources/lib/libRblas.0.dylib
## LAPACK: /Library/Frameworks/R.framework/Versions/4.2-arm64/Resources/lib/libRlapack.dylib
## 
## locale:
## [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
## 
## attached base packages:
## [1] stats     graphics  grDevices utils     datasets  methods   base     
## 
## other attached packages:
## [1] naniar_0.6.1   GAIPE_1.1      psych_2.2.5    haven_2.5.1    semPlot_1.1.6 
## [6] semTools_0.5-6 lavaan_0.6-15 
## 
## loaded via a namespace (and not attached):
##   [1] minqa_1.2.5         colorspace_2.0-3    deldir_1.0-6       
##   [4] ellipsis_0.3.2      visdat_0.5.3        htmlTable_2.4.1    
##   [7] corpcor_1.6.10      base64enc_0.1-3     rstudioapi_0.14    
##  [10] farver_2.1.1        fansi_1.0.3         splines_4.2.2      
##  [13] mnormt_2.1.0        cachem_1.0.6        knitr_1.40         
##  [16] glasso_1.11         Formula_1.2-4       jsonlite_1.8.0     
##  [19] nloptr_2.0.3        cluster_2.1.4       png_0.1-7          
##  [22] compiler_4.2.2      backports_1.4.1     assertthat_0.2.1   
##  [25] Matrix_1.5-1        fastmap_1.1.0       cli_3.4.0          
##  [28] htmltools_0.5.5     tools_4.2.2         igraph_1.4.2       
##  [31] OpenMx_2.21.8       coda_0.19-4         gtable_0.3.1       
##  [34] glue_1.6.2          reshape2_1.4.4      dplyr_1.0.10       
##  [37] Rcpp_1.0.9          carData_3.0-5       jquerylib_0.1.4    
##  [40] vctrs_0.5.1         nlme_3.1-160        lisrelToR_0.1.5    
##  [43] xfun_0.33           stringr_1.4.1       openxlsx_4.2.5.1   
##  [46] lme4_1.1-30         lifecycle_1.0.3     gtools_3.9.4       
##  [49] XML_3.99-0.14       MASS_7.3-58.1       scales_1.2.1       
##  [52] hms_1.1.2           kutils_1.70         parallel_4.2.2     
##  [55] RColorBrewer_1.1-3  yaml_2.3.5          pbapply_1.7-0      
##  [58] gridExtra_2.3       ggplot2_3.4.0       sass_0.4.2         
##  [61] rpart_4.1.19        latticeExtra_0.6-30 stringi_1.7.8      
##  [64] highr_0.9           sem_3.1-15          checkmate_2.1.0    
##  [67] boot_1.3-28         zip_2.2.2           rlang_1.0.6        
##  [70] pkgconfig_2.0.3     arm_1.13-1          evaluate_0.16      
##  [73] lattice_0.20-45     purrr_0.3.4         labeling_0.4.2     
##  [76] htmlwidgets_1.6.2   tidyselect_1.1.2    plyr_1.8.7         
##  [79] magrittr_2.0.3      R6_2.5.1            generics_0.1.3     
##  [82] Hmisc_4.7-1         DBI_1.1.3           pillar_1.8.1       
##  [85] foreign_0.8-83      withr_2.5.0         rockchalk_1.8.157  
##  [88] survival_3.4-0      abind_1.4-5         nnet_7.3-18        
##  [91] tibble_3.1.8        interp_1.1-3        fdrtool_1.2.17     
##  [94] utf8_1.2.2          rmarkdown_2.16      jpeg_0.1-9         
##  [97] grid_4.2.2          qgraph_1.9.4        data.table_1.14.2  
## [100] pbivnorm_0.6.0      forcats_0.5.2       digest_0.6.29      
## [103] xtable_1.8-4        mi_1.1              tidyr_1.2.1        
## [106] RcppParallel_5.1.7  stats4_4.2.2        munsell_0.5.0      
## [109] bslib_0.4.0         quadprog_1.5-8
citation("lavaan")
## 
## To cite lavaan in publications use:
## 
##   Yves Rosseel (2012). lavaan: An R Package for Structural Equation
##   Modeling. Journal of Statistical Software, 48(2), 1-36.
##   https://doi.org/10.18637/jss.v048.i02
## 
## A BibTeX entry for LaTeX users is
## 
##   @Article{,
##     title = {{lavaan}: An {R} Package for Structural Equation Modeling},
##     author = {Yves Rosseel},
##     journal = {Journal of Statistical Software},
##     year = {2012},
##     volume = {48},
##     number = {2},
##     pages = {1--36},
##     doi = {10.18637/jss.v048.i02},
##   }
citation("semPlot")
## 
## To cite package 'semPlot' in publications use:
## 
##   Epskamp S (2022). _semPlot: Path Diagrams and Visual Analysis of
##   Various SEM Packages' Output_. R package version 1.1.6,
##   <https://CRAN.R-project.org/package=semPlot>.
## 
## A BibTeX entry for LaTeX users is
## 
##   @Manual{,
##     title = {semPlot: Path Diagrams and Visual Analysis of Various SEM Packages'
## Output},
##     author = {Sacha Epskamp},
##     year = {2022},
##     note = {R package version 1.1.6},
##     url = {https://CRAN.R-project.org/package=semPlot},
##   }
citation("semTools")
## 
## The maintainer and *primary* contributors to this package are listed as
## authors, but this package is a collaborative work. The maintainer(s)
## cannot take credit for others' contributions. Whenever possible, please
## cite the paper(s) associated with the development of a particular
## function (e.g., permuteMeasEq or parcelAllocation) or tutorials about
## how to use them (e.g., probe2WayMC and related functions), which are
## listed in the References section of its associated help page.
## Otherwise, please use the following citation for the package as a
## whole:
## 
##   Jorgensen, T. D., Pornprasertmanit, S., Schoemann, A. M., & Rosseel,
##   Y. (2022). semTools: Useful tools for structural equation modeling. R
##   package version 0.5-6. Retrieved from
##   https://CRAN.R-project.org/package=semTools
## 
## A BibTeX entry for LaTeX users is
## 
##   @Manual{,
##     title = {\texttt{semTools}: {U}seful tools for structural equation modeling},
##     author = {Terrence D. Jorgensen and Sunthud Pornprasertmanit and Alexander M. Schoemann and Yves Rosseel},
##     year = {2022},
##     note = {R package version 0.5-6},
##     url = {https://CRAN.R-project.org/package=semTools},
##   }
citation ("haven")
## 
## To cite package 'haven' in publications use:
## 
##   Wickham H, Miller E, Smith D (2022). _haven: Import and Export
##   'SPSS', 'Stata' and 'SAS' Files_. R package version 2.5.1,
##   <https://CRAN.R-project.org/package=haven>.
## 
## A BibTeX entry for LaTeX users is
## 
##   @Manual{,
##     title = {haven: Import and Export 'SPSS', 'Stata' and 'SAS' Files},
##     author = {Hadley Wickham and Evan Miller and Danny Smith},
##     year = {2022},
##     note = {R package version 2.5.1},
##     url = {https://CRAN.R-project.org/package=haven},
##   }
citation("psych")
## 
## To cite the psych package in publications use:
## 
##   Revelle, W. (2022) psych: Procedures for Personality and
##   Psychological Research, Northwestern University, Evanston, Illinois,
##   USA, https://CRAN.R-project.org/package=psych Version = 2.2.5.
## 
## A BibTeX entry for LaTeX users is
## 
##   @Manual{,
##     title = {psych: Procedures for Psychological, Psychometric, and Personality Research},
##     author = {William Revelle},
##     organization = { Northwestern University},
##     address = { Evanston, Illinois},
##     year = {2022},
##     note = {R package version 2.2.5},
##     url = {https://CRAN.R-project.org/package=psych},
##   }
citation("GAIPE")
## 
## To cite package 'GAIPE' in publications use:
## 
##   Lin T (2022). _GAIPE: Graphical Extension with Accuracy in Parameter
##   Estimation (GAIPE)_. R package version 1.1,
##   <https://CRAN.R-project.org/package=GAIPE>.
## 
## A BibTeX entry for LaTeX users is
## 
##   @Manual{,
##     title = {GAIPE: Graphical Extension with Accuracy in Parameter Estimation
## (GAIPE)},
##     author = {Tzu-Yao Lin},
##     year = {2022},
##     note = {R package version 1.1},
##     url = {https://CRAN.R-project.org/package=GAIPE},
##   }
## 
## ATTENTION: This citation information has been auto-generated from the
## package DESCRIPTION file and may need manual editing, see
## 'help("citation")'.
citation("naniar") #getting package citations 
## 
## To cite package 'naniar' in publications use:
## 
##   Tierney N, Cook D, McBain M, Fay C (2021). _naniar: Data Structures,
##   Summaries, and Visualisations for Missing Data_. R package version
##   0.6.1, <https://CRAN.R-project.org/package=naniar>.
## 
## A BibTeX entry for LaTeX users is
## 
##   @Manual{,
##     title = {naniar: Data Structures, Summaries, and Visualisations for Missing Data},
##     author = {Nicholas Tierney and Di Cook and Miles McBain and Colin Fay},
##     year = {2021},
##     note = {R package version 0.6.1},
##     url = {https://CRAN.R-project.org/package=naniar},
##   }