1. Is data suitable for factor analysis?

a. is sample large enough? - Yes, N = 2571

b. variable type: 1-5 Likert scale (interval, so ok)

c. 23-items (more than 1 per 20 participants)

d. is there any missing data? - No

## missing
##    0 
## 2571

e. check for outliers and drop outliers

## [1] 49.72823
## [1] 23
##    Mode   FALSE    TRUE 
## logical      97    2474

f. describe items

##     vars    n mean   sd median trimmed  mad min max range  skew kurtosis   se
## Q01    1 2474 3.64 0.80      4    3.67 0.00   1   5     4 -0.63     0.63 0.02
## Q02    2 2474 4.37 0.84      5    4.53 0.00   1   5     4 -1.41     1.74 0.02
## Q03    3 2474 2.61 1.06      3    2.60 1.48   1   5     4  0.06    -0.75 0.02
## Q04    4 2474 3.24 0.92      3    3.28 1.48   1   5     4 -0.37    -0.25 0.02
## Q05    5 2474 3.29 0.94      3    3.34 1.48   1   5     4 -0.46    -0.42 0.02
## Q06    6 2474 3.79 1.09      4    3.93 1.48   1   5     4 -0.93     0.23 0.02
## Q07    7 2474 3.11 1.07      3    3.13 1.48   1   5     4 -0.20    -0.81 0.02
## Q08    8 2474 3.77 0.85      4    3.85 0.00   1   5     4 -1.05     1.58 0.02
## Q09    9 2474 3.15 1.25      3    3.16 1.48   1   5     4  0.07    -1.13 0.03
## Q10   10 2474 3.73 0.85      4    3.80 0.00   1   5     4 -0.82     0.61 0.02
## Q11   11 2474 3.76 0.85      4    3.83 0.00   1   5     4 -0.81     0.94 0.02
## Q12   12 2474 2.87 0.88      3    2.90 1.48   1   5     4 -0.19    -0.13 0.02
## Q13   13 2474 3.57 0.92      4    3.61 1.48   1   5     4 -0.60     0.06 0.02
## Q14   14 2474 3.16 0.97      3    3.19 1.48   1   5     4 -0.28    -0.31 0.02
## Q15   15 2474 3.26 0.98      3    3.30 1.48   1   5     4 -0.43    -0.39 0.02
## Q16   16 2474 3.15 0.89      3    3.20 1.48   1   5     4 -0.39    -0.07 0.02
## Q17   17 2474 3.56 0.85      4    3.62 0.00   1   5     4 -0.75     0.56 0.02
## Q18   18 2474 3.46 1.02      4    3.50 1.48   1   5     4 -0.47    -0.18 0.02
## Q19   19 2474 3.71 1.09      4    3.78 1.48   1   5     4 -0.46    -0.73 0.02
## Q20   20 2474 2.40 1.02      2    2.35 1.48   1   5     4  0.36    -0.65 0.02
## Q21   21 2474 2.86 0.96      3    2.90 1.48   1   5     4 -0.13    -0.75 0.02
## Q22   22 2474 3.11 1.01      3    3.07 1.48   1   5     4  0.08    -0.66 0.02
## Q23   23 2474 2.57 1.02      2    2.52 1.48   1   5     4  0.59    -0.12 0.02

i. histograms of item 2

ii. histogram of item 8

2. Testing Assumptions

a. correlation matrix

symnum(corr2)
##     Q01 Q02 Q03 Q04 Q05 Q06 Q07 Q08 Q09 Q10 Q11 Q12 Q13 Q14 Q15 Q16 Q17 Q18 Q19
## Q01 1                                                                          
## Q02     1                                                                      
## Q03 .   .   1                                                                  
## Q04 .       .   1                                                              
## Q05 .       .   .   1                                                          
## Q06                     1                                                      
## Q07 .       .   .   .   .   1                                                  
## Q08 .           .           .   1                                              
## Q09     .   .                       1                                          
## Q10                     .               1                                      
## Q11 .       .   .   .   .   .   ,           1                                  
## Q12 .       .   .   .   .   .               .   1                              
## Q13 .       .   .   .   .   .   .       .   .   .   1                          
## Q14 .       .   .   .   .   .               .   .   .   1                      
## Q15         .   .       .   .   .       .   .   .   .   .   1                  
## Q16 .       .   .   .       .   .           .   .   .   .   .   1              
## Q17 .       .   .   .       .   ,           ,   .   .   .   .   .   1          
## Q18 .       .   .   .   .   .           .   .   .   .   .   .   .   .   1      
## Q19         .                                                               1  
## Q20         .                                   .                              
## Q21 .       .   .   .       .   .           .   .   .   .   .   .   .   .      
## Q22                                                                            
## Q23                                                                            
##     Q20 Q21 Q22 Q23
## Q01                
## Q02                
## Q03                
## Q04                
## Q05                
## Q06                
## Q07                
## Q08                
## Q09                
## Q10                
## Q11                
## Q12                
## Q13                
## Q14                
## Q15                
## Q16                
## Q17                
## Q18                
## Q19                
## Q20 1              
## Q21 .   1          
## Q22         1      
## Q23             1  
## attr(,"legend")
## [1] 0 ' ' 0.3 '.' 0.6 ',' 0.8 '+' 0.9 '*' 0.95 'B' 1

b. distribution of the correlation matrix

##    vars   n mean   sd median trimmed  mad   min  max range  skew kurtosis   se
## X1    1 253 0.17 0.26   0.26    0.18 0.23 -0.36 0.65     1 -0.41    -1.33 0.02

c. Linearity

d. Normality

e. Homogeneity & Homoscidasticity

f. Additivity - Bartlett’s test of Sphericity

## $chisq
## [1] 19534.27
## 
## $p.value
## [1] 0
## 
## $df
## [1] 253

g. Sample size - KMO test for sampling adequacy

## Kaiser-Meyer-Olkin factor adequacy
## Call: KMO(r = corr2)
## Overall MSA =  0.93
## MSA for each item = 
##  Q01  Q02  Q03  Q04  Q05  Q06  Q07  Q08  Q09  Q10  Q11  Q12  Q13  Q14  Q15  Q16 
## 0.94 0.88 0.95 0.96 0.96 0.90 0.94 0.88 0.85 0.96 0.91 0.96 0.95 0.97 0.95 0.94 
##  Q17  Q18  Q19  Q20  Q21  Q22  Q23 
## 0.93 0.95 0.95 0.89 0.93 0.89 0.79

h. matrix determinants

## [1] 0.0003611339

5. How many factors to be retained?

a. old Kaiser (eigenvalues > 1) vs. new Kaiser criterion (eigenvalues > .7)

## Parallel analysis suggests that the number of factors =  6  and the number of components =  NA
## [1] 1
## [1] 2

b. Scree Plot and Parallel Analysis

6. Factor rotation? Orthogonal or Oblique?

a. without rotation

i. minres

M1 <-fa(d2, nfactors = 4, fm = "minres", SMC = TRUE, rotate="none")  
print.psych(M1, cut=.3)
## Factor Analysis using method =  minres
## Call: fa(r = d2, nfactors = 4, rotate = "none", SMC = TRUE, fm = "minres")
## Standardized loadings (pattern matrix) based upon correlation matrix
##       MR1   MR2   MR3   MR4   h2   u2 com
## Q01  0.57                   0.39 0.61 1.5
## Q02        0.40             0.30 0.70 2.6
## Q03  0.61                   0.48 0.52 1.6
## Q04  0.61                   0.42 0.58 1.3
## Q05  0.53                   0.32 0.68 1.2
## Q06  0.56        0.51       0.61 0.39 2.2
## Q07  0.67                   0.51 0.49 1.3
## Q08  0.56  0.48             0.67 0.33 2.7
## Q09        0.47             0.36 0.64 2.3
## Q10  0.41                   0.20 0.80 1.4
## Q11  0.66  0.32             0.65 0.35 2.0
## Q12  0.65                   0.46 0.54 1.2
## Q13  0.66                   0.49 0.51 1.2
## Q14  0.63                   0.42 0.58 1.1
## Q15  0.57                   0.33 0.67 1.1
## Q16  0.65                   0.46 0.54 1.1
## Q17  0.64  0.36             0.59 0.41 1.9
## Q18  0.70                   0.57 0.43 1.3
## Q19 -0.42                   0.26 0.74 1.8
## Q20  0.42                   0.28 0.72 2.2
## Q21  0.64                   0.48 0.52 1.4
## Q22 -0.30                   0.26 0.74 3.1
## Q23                         0.11 0.89 3.1
## 
##                        MR1  MR2  MR3  MR4
## SS loadings           6.98 1.15 0.83 0.64
## Proportion Var        0.30 0.05 0.04 0.03
## Cumulative Var        0.30 0.35 0.39 0.42
## Proportion Explained  0.73 0.12 0.09 0.07
## Cumulative Proportion 0.73 0.85 0.93 1.00
## 
## Mean item complexity =  1.8
## Test of the hypothesis that 4 factors are sufficient.
## 
## The degrees of freedom for the null model are  253  and the objective function was  7.93 with Chi Square of  19534.27
## The degrees of freedom for the model are 167  and the objective function was  0.43 
## 
## The root mean square of the residuals (RMSR) is  0.02 
## The df corrected root mean square of the residuals is  0.03 
## 
## The harmonic number of observations is  2474 with the empirical chi square  779.08  with prob <  1e-79 
## The total number of observations was  2474  with Likelihood Chi Square =  1065.21  with prob <  1.1e-130 
## 
## Tucker Lewis Index of factoring reliability =  0.929
## RMSEA index =  0.047  and the 90 % confidence intervals are  0.044 0.049
## BIC =  -239.66
## Fit based upon off diagonal values = 0.99
## Measures of factor score adequacy             
##                                                    MR1  MR2  MR3  MR4
## Correlation of (regression) scores with factors   0.97 0.83 0.80 0.74
## Multiple R square of scores with factors          0.93 0.69 0.64 0.54
## Minimum correlation of possible factor scores     0.86 0.38 0.29 0.08

ii. maximum likelihood

M2 <- fa(d2, nfactors = 4, fm = "ml", SMC = TRUE, rotate = "none")
print.psych(M2, cut=.3)
## Factor Analysis using method =  ml
## Call: fa(r = d2, nfactors = 4, rotate = "none", SMC = TRUE, fm = "ml")
## Standardized loadings (pattern matrix) based upon correlation matrix
##       ML1   ML2   ML3   ML4    h2   u2 com
## Q01  0.57                   0.405 0.59 1.5
## Q02              0.32       0.311 0.69 3.8
## Q03  0.59       -0.31       0.477 0.52 1.7
## Q04  0.60                   0.426 0.57 1.3
## Q05  0.52                   0.323 0.68 1.4
## Q06  0.58        0.48       0.637 0.36 2.4
## Q07  0.67                   0.514 0.49 1.3
## Q08  0.61  0.55             0.671 0.33 2.0
## Q09        0.32        0.34 0.365 0.64 3.8
## Q10  0.40                   0.193 0.81 1.4
## Q11  0.69  0.38             0.663 0.34 1.7
## Q12  0.63                   0.459 0.54 1.3
## Q13  0.67                   0.488 0.51 1.2
## Q14  0.62                   0.424 0.58 1.2
## Q15  0.57                   0.330 0.67 1.0
## Q16  0.64                   0.464 0.54 1.3
## Q17  0.67  0.37             0.582 0.42 1.6
## Q18  0.70                   0.573 0.43 1.4
## Q19 -0.40                   0.253 0.75 2.2
## Q20  0.40       -0.31       0.267 0.73 2.0
## Q21  0.62                   0.458 0.54 1.4
## Q22                    0.32 0.232 0.77 2.9
## Q23                         0.095 0.90 2.3
## 
##                        ML1  ML2  ML3  ML4
## SS loadings           6.93 1.09 0.90 0.69
## Proportion Var        0.30 0.05 0.04 0.03
## Cumulative Var        0.30 0.35 0.39 0.42
## Proportion Explained  0.72 0.11 0.09 0.07
## Cumulative Proportion 0.72 0.84 0.93 1.00
## 
## Mean item complexity =  1.8
## Test of the hypothesis that 4 factors are sufficient.
## 
## The degrees of freedom for the null model are  253  and the objective function was  7.93 with Chi Square of  19534.27
## The degrees of freedom for the model are 167  and the objective function was  0.43 
## 
## The root mean square of the residuals (RMSR) is  0.03 
## The df corrected root mean square of the residuals is  0.03 
## 
## The harmonic number of observations is  2474 with the empirical chi square  794.58  with prob <  2.2e-82 
## The total number of observations was  2474  with Likelihood Chi Square =  1053.65  with prob <  1.5e-128 
## 
## Tucker Lewis Index of factoring reliability =  0.93
## RMSEA index =  0.046  and the 90 % confidence intervals are  0.044 0.049
## BIC =  -251.22
## Fit based upon off diagonal values = 0.99
## Measures of factor score adequacy             
##                                                    ML1  ML2  ML3  ML4
## Correlation of (regression) scores with factors   0.97 0.85 0.80 0.73
## Multiple R square of scores with factors          0.93 0.72 0.63 0.53
## Minimum correlation of possible factor scores     0.87 0.44 0.27 0.06

iii. principal axis

M3 <- fa(d2, nfactors = 4, fm = "pa", SMC = TRUE, rotate = "none") 
print.psych(M3, cut=.3)
## Factor Analysis using method =  pa
## Call: fa(r = d2, nfactors = 4, rotate = "none", SMC = TRUE, fm = "pa")
## Standardized loadings (pattern matrix) based upon correlation matrix
##       PA1   PA2   PA3   PA4   h2   u2 com
## Q01  0.57                   0.39 0.61 1.5
## Q02        0.40             0.30 0.70 2.6
## Q03  0.61                   0.48 0.52 1.6
## Q04  0.61                   0.42 0.58 1.3
## Q05  0.53                   0.32 0.68 1.2
## Q06  0.56        0.51       0.61 0.39 2.2
## Q07  0.67                   0.51 0.49 1.3
## Q08  0.56  0.48             0.67 0.33 2.7
## Q09        0.47             0.36 0.64 2.2
## Q10  0.41                   0.20 0.80 1.4
## Q11  0.66  0.32             0.65 0.35 2.0
## Q12  0.65                   0.46 0.54 1.2
## Q13  0.66                   0.49 0.51 1.2
## Q14  0.63                   0.42 0.58 1.1
## Q15  0.57                   0.33 0.67 1.1
## Q16  0.65                   0.46 0.54 1.1
## Q17  0.64  0.36             0.59 0.41 1.9
## Q18  0.70                   0.57 0.43 1.3
## Q19 -0.42                   0.26 0.74 1.8
## Q20  0.42                   0.28 0.72 2.2
## Q21  0.64                   0.48 0.52 1.4
## Q22 -0.30                   0.26 0.74 3.1
## Q23                         0.11 0.89 3.1
## 
##                        PA1  PA2  PA3  PA4
## SS loadings           6.98 1.15 0.83 0.64
## Proportion Var        0.30 0.05 0.04 0.03
## Cumulative Var        0.30 0.35 0.39 0.42
## Proportion Explained  0.73 0.12 0.09 0.07
## Cumulative Proportion 0.73 0.85 0.93 1.00
## 
## Mean item complexity =  1.8
## Test of the hypothesis that 4 factors are sufficient.
## 
## The degrees of freedom for the null model are  253  and the objective function was  7.93 with Chi Square of  19534.27
## The degrees of freedom for the model are 167  and the objective function was  0.43 
## 
## The root mean square of the residuals (RMSR) is  0.02 
## The df corrected root mean square of the residuals is  0.03 
## 
## The harmonic number of observations is  2474 with the empirical chi square  779.09  with prob <  1e-79 
## The total number of observations was  2474  with Likelihood Chi Square =  1065.48  with prob <  1e-130 
## 
## Tucker Lewis Index of factoring reliability =  0.929
## RMSEA index =  0.047  and the 90 % confidence intervals are  0.044 0.049
## BIC =  -239.39
## Fit based upon off diagonal values = 0.99
## Measures of factor score adequacy             
##                                                    PA1  PA2  PA3  PA4
## Correlation of (regression) scores with factors   0.97 0.83 0.80 0.74
## Multiple R square of scores with factors          0.93 0.69 0.64 0.54
## Minimum correlation of possible factor scores     0.86 0.37 0.28 0.08

b. with rotations

i. with orthogonal (varimax) rotation

M4 <- fa(d2, nfactors = 4, fm = "pa", SMC=TRUE, rotate = "varimax") 
print.psych(M4, cut=.3)
## Factor Analysis using method =  pa
## Call: fa(r = d2, nfactors = 4, rotate = "varimax", SMC = TRUE, fm = "pa")
## Standardized loadings (pattern matrix) based upon correlation matrix
##       PA1   PA3   PA4   PA2   h2   u2 com
## Q01  0.52                   0.39 0.61 1.9
## Q02                   -0.51 0.30 0.70 1.3
## Q03  0.50              0.42 0.48 0.52 2.5
## Q04  0.54                   0.42 0.58 1.9
## Q05  0.46                   0.32 0.68 2.0
## Q06        0.76             0.61 0.39 1.1
## Q07  0.36  0.58             0.51 0.49 2.0
## Q08              0.76       0.67 0.33 1.3
## Q09                   -0.58 0.36 0.64 1.2
## Q10        0.38             0.20 0.80 1.7
## Q11              0.69       0.65 0.35 1.7
## Q12  0.50  0.40             0.46 0.54 2.3
## Q13        0.57             0.49 0.51 2.1
## Q14  0.39  0.48             0.42 0.58 2.4
## Q15        0.39             0.33 0.67 3.3
## Q16  0.54                   0.46 0.54 2.2
## Q17  0.30        0.65       0.59 0.41 1.8
## Q18  0.37  0.63             0.57 0.43 1.9
## Q19                   -0.38 0.26 0.74 2.3
## Q20  0.48                   0.28 0.72 1.5
## Q21  0.61                   0.48 0.52 1.7
## Q22                   -0.47 0.26 0.74 1.3
## Q23                   -0.31 0.11 0.89 1.2
## 
##                        PA1  PA3  PA4  PA2
## SS loadings           3.09 2.94 2.02 1.55
## Proportion Var        0.13 0.13 0.09 0.07
## Cumulative Var        0.13 0.26 0.35 0.42
## Proportion Explained  0.32 0.31 0.21 0.16
## Cumulative Proportion 0.32 0.63 0.84 1.00
## 
## Mean item complexity =  1.8
## Test of the hypothesis that 4 factors are sufficient.
## 
## The degrees of freedom for the null model are  253  and the objective function was  7.93 with Chi Square of  19534.27
## The degrees of freedom for the model are 167  and the objective function was  0.43 
## 
## The root mean square of the residuals (RMSR) is  0.02 
## The df corrected root mean square of the residuals is  0.03 
## 
## The harmonic number of observations is  2474 with the empirical chi square  779.09  with prob <  1e-79 
## The total number of observations was  2474  with Likelihood Chi Square =  1065.48  with prob <  1e-130 
## 
## Tucker Lewis Index of factoring reliability =  0.929
## RMSEA index =  0.047  and the 90 % confidence intervals are  0.044 0.049
## BIC =  -239.39
## Fit based upon off diagonal values = 0.99
## Measures of factor score adequacy             
##                                                    PA1  PA3  PA4  PA2
## Correlation of (regression) scores with factors   0.83 0.86 0.87 0.78
## Multiple R square of scores with factors          0.69 0.74 0.75 0.61
## Minimum correlation of possible factor scores     0.39 0.49 0.51 0.22

ii. with oblique (promax) rotation

M5 <- fa(d2, nfactors = 4, fm = "pa", SMC=TRUE, rotate = "promax") 
print.psych(M5, cut=.3)
## Factor Analysis using method =  pa
## Call: fa(r = d2, nfactors = 4, rotate = "promax", SMC = TRUE, fm = "pa")
## Standardized loadings (pattern matrix) based upon correlation matrix
##       PA1   PA3   PA4   PA2   h2   u2 com
## Q01  0.58                   0.39 0.61 1.3
## Q02                    0.50 0.30 0.70 1.4
## Q03  0.51             -0.31 0.48 0.52 1.7
## Q04  0.59                   0.42 0.58 1.2
## Q05  0.49                   0.32 0.68 1.2
## Q06        0.98             0.61 0.39 1.2
## Q07        0.58             0.51 0.49 1.3
## Q08              0.84       0.67 0.33 1.1
## Q09                    0.59 0.36 0.64 1.1
## Q10        0.41             0.20 0.80 1.0
## Q11              0.72       0.65 0.35 1.1
## Q12  0.50                   0.46 0.54 1.7
## Q13        0.57             0.49 0.51 1.1
## Q14        0.44             0.42 0.58 1.7
## Q15        0.31             0.33 0.67 2.1
## Q16  0.56                   0.46 0.54 1.1
## Q17              0.66       0.59 0.41 1.1
## Q18        0.65             0.57 0.43 1.2
## Q19                    0.33 0.26 0.74 1.9
## Q20  0.60                   0.28 0.72 1.3
## Q21  0.69                   0.48 0.52 1.0
## Q22                    0.49 0.26 0.74 1.3
## Q23                    0.35 0.11 0.89 1.4
## 
##                        PA1  PA3  PA4  PA2
## SS loadings           3.47 2.93 1.89 1.32
## Proportion Var        0.15 0.13 0.08 0.06
## Cumulative Var        0.15 0.28 0.36 0.42
## Proportion Explained  0.36 0.30 0.20 0.14
## Cumulative Proportion 0.36 0.67 0.86 1.00
## 
##  With factor correlations of 
##       PA1   PA3   PA4   PA2
## PA1  1.00  0.69  0.57 -0.46
## PA3  0.69  1.00  0.58 -0.41
## PA4  0.57  0.58  1.00 -0.23
## PA2 -0.46 -0.41 -0.23  1.00
## 
## Mean item complexity =  1.3
## Test of the hypothesis that 4 factors are sufficient.
## 
## The degrees of freedom for the null model are  253  and the objective function was  7.93 with Chi Square of  19534.27
## The degrees of freedom for the model are 167  and the objective function was  0.43 
## 
## The root mean square of the residuals (RMSR) is  0.02 
## The df corrected root mean square of the residuals is  0.03 
## 
## The harmonic number of observations is  2474 with the empirical chi square  779.09  with prob <  1e-79 
## The total number of observations was  2474  with Likelihood Chi Square =  1065.48  with prob <  1e-130 
## 
## Tucker Lewis Index of factoring reliability =  0.929
## RMSEA index =  0.047  and the 90 % confidence intervals are  0.044 0.049
## BIC =  -239.39
## Fit based upon off diagonal values = 0.99
## Measures of factor score adequacy             
##                                                    PA1  PA3  PA4  PA2
## Correlation of (regression) scores with factors   0.93 0.93 0.92 0.83
## Multiple R square of scores with factors          0.87 0.87 0.84 0.68
## Minimum correlation of possible factor scores     0.73 0.75 0.69 0.37

- Drop item 3 for promax rotation (load onto multiple factors)

d3 <- d2[,c(1, 2,    4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)]

M6 <- fa(d3, nfactors = 4, fm = "pa", SMC = TRUE, rotate = "promax") 
print.psych(M6, cut=.3)
## Factor Analysis using method =  pa
## Call: fa(r = d3, nfactors = 4, rotate = "promax", SMC = TRUE, fm = "pa")
## Standardized loadings (pattern matrix) based upon correlation matrix
##       PA3   PA1   PA4   PA2   h2   u2 com
## Q01        0.57             0.39 0.61 1.3
## Q02                    0.49 0.28 0.72 1.4
## Q04        0.57             0.42 0.58 1.2
## Q05        0.49             0.32 0.68 1.1
## Q06  0.99 -0.31             0.61 0.39 1.2
## Q07  0.60                   0.51 0.49 1.2
## Q08              0.85       0.67 0.33 1.1
## Q09                    0.59 0.36 0.64 1.1
## Q10  0.41                   0.20 0.80 1.0
## Q11              0.72       0.65 0.35 1.1
## Q12        0.49             0.46 0.54 1.8
## Q13  0.57                   0.49 0.51 1.1
## Q14  0.45                   0.42 0.58 1.7
## Q15  0.31                   0.34 0.66 2.2
## Q16        0.56             0.46 0.54 1.1
## Q17              0.66       0.59 0.41 1.1
## Q18  0.67                   0.57 0.43 1.2
## Q19                    0.33 0.25 0.75 1.9
## Q20        0.61             0.29 0.71 1.4
## Q21        0.69             0.48 0.52 1.0
## Q22                    0.50 0.27 0.73 1.2
## Q23                    0.34 0.10 0.90 1.4
## 
##                        PA3  PA1  PA4  PA2
## SS loadings           2.95 3.10 1.90 1.18
## Proportion Var        0.13 0.14 0.09 0.05
## Cumulative Var        0.13 0.28 0.36 0.41
## Proportion Explained  0.32 0.34 0.21 0.13
## Cumulative Proportion 0.32 0.66 0.87 1.00
## 
##  With factor correlations of 
##       PA3   PA1   PA4   PA2
## PA3  1.00  0.70  0.58 -0.42
## PA1  0.70  1.00  0.57 -0.44
## PA4  0.58  0.57  1.00 -0.23
## PA2 -0.42 -0.44 -0.23  1.00
## 
## Mean item complexity =  1.3
## Test of the hypothesis that 4 factors are sufficient.
## 
## The degrees of freedom for the null model are  231  and the objective function was  7.4 with Chi Square of  18233.31
## The degrees of freedom for the model are 149  and the objective function was  0.41 
## 
## The root mean square of the residuals (RMSR) is  0.03 
## The df corrected root mean square of the residuals is  0.03 
## 
## The harmonic number of observations is  2474 with the empirical chi square  743.33  with prob <  1e-79 
## The total number of observations was  2474  with Likelihood Chi Square =  1012.53  with prob <  2.4e-128 
## 
## Tucker Lewis Index of factoring reliability =  0.926
## RMSEA index =  0.048  and the 90 % confidence intervals are  0.046 0.051
## BIC =  -151.7
## Fit based upon off diagonal values = 0.99
## Measures of factor score adequacy             
##                                                    PA3  PA1  PA4  PA2
## Correlation of (regression) scores with factors   0.94 0.92 0.92 0.81
## Multiple R square of scores with factors          0.87 0.85 0.84 0.66
## Minimum correlation of possible factor scores     0.75 0.71 0.69 0.31

- Drop item 6 for promax rotation (loads onto multiple factors)

d4 <- d2[,c(1, 2,    4, 5,   7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)]

M7 <- fa(d4, nfactors = 4, fm = "pa", SMC = TRUE, rotate = "promax") 
print.psych(M7, cut=.3)
## Factor Analysis using method =  pa
## Call: fa(r = d4, nfactors = 4, rotate = "promax", SMC = TRUE, fm = "pa")
## Standardized loadings (pattern matrix) based upon correlation matrix
##       PA1   PA3   PA2   PA4   h2   u2 com
## Q01  0.44                   0.36 0.64 1.7
## Q02              0.46       0.28 0.72 1.4
## Q04  0.47                   0.40 0.60 1.6
## Q05  0.45                   0.30 0.70 1.3
## Q07  0.70                   0.46 0.54 1.0
## Q08        0.87             0.68 0.32 1.0
## Q09              0.58       0.36 0.64 1.1
## Q10  0.52                   0.20 0.80 1.2
## Q11        0.73             0.64 0.36 1.1
## Q12  0.67                   0.47 0.53 1.1
## Q13  0.71                   0.48 0.52 1.1
## Q14  0.69                   0.43 0.57 1.0
## Q15  0.44                   0.33 0.67 1.4
## Q16  0.49                   0.44 0.56 1.2
## Q17        0.66             0.59 0.41 1.1
## Q18  0.85                   0.55 0.45 1.0
## Q19              0.31       0.25 0.75 2.1
## Q20                    0.69 0.43 0.57 1.1
## Q21                    0.57 0.57 0.43 1.5
## Q22              0.51       0.28 0.72 1.1
## Q23              0.34       0.11 0.89 1.2
## 
##                        PA1  PA3  PA2  PA4
## SS loadings           4.31 1.92 1.15 1.21
## Proportion Var        0.21 0.09 0.05 0.06
## Cumulative Var        0.21 0.30 0.35 0.41
## Proportion Explained  0.50 0.22 0.13 0.14
## Cumulative Proportion 0.50 0.73 0.86 1.00
## 
##  With factor correlations of 
##       PA1   PA3   PA2   PA4
## PA1  1.00  0.64 -0.43  0.63
## PA3  0.64  1.00 -0.21  0.42
## PA2 -0.43 -0.21  1.00 -0.32
## PA4  0.63  0.42 -0.32  1.00
## 
## Mean item complexity =  1.3
## Test of the hypothesis that 4 factors are sufficient.
## 
## The degrees of freedom for the null model are  210  and the objective function was  6.81 with Chi Square of  16788.88
## The degrees of freedom for the model are 132  and the objective function was  0.36 
## 
## The root mean square of the residuals (RMSR) is  0.03 
## The df corrected root mean square of the residuals is  0.03 
## 
## The harmonic number of observations is  2474 with the empirical chi square  652.57  with prob <  7.2e-70 
## The total number of observations was  2474  with Likelihood Chi Square =  875.54  with prob <  5.2e-110 
## 
## Tucker Lewis Index of factoring reliability =  0.929
## RMSEA index =  0.048  and the 90 % confidence intervals are  0.045 0.051
## BIC =  -155.86
## Fit based upon off diagonal values = 0.99
## Measures of factor score adequacy             
##                                                    PA1  PA3  PA2  PA4
## Correlation of (regression) scores with factors   0.95 0.92 0.80 0.85
## Multiple R square of scores with factors          0.90 0.85 0.64 0.72
## Minimum correlation of possible factor scores     0.79 0.70 0.29 0.44

iii. with oblique (oblimin) rotation

M8 <- fa(d2, nfactors = 4, fm = "pa", rotate = "oblimin") 
print.psych(M8, cut=.3)
## Factor Analysis using method =  pa
## Call: fa(r = d2, nfactors = 4, rotate = "oblimin", fm = "pa")
## Standardized loadings (pattern matrix) based upon correlation matrix
##       PA1   PA3   PA4   PA2   h2   u2 com
## Q01  0.52                   0.39 0.61 1.3
## Q02                    0.53 0.30 0.70 1.1
## Q03  0.40             -0.38 0.48 0.52 2.1
## Q04  0.53                   0.42 0.58 1.2
## Q05  0.45                   0.32 0.68 1.2
## Q06        0.82             0.61 0.39 1.0
## Q07        0.50             0.51 0.49 1.6
## Q08              0.86       0.67 0.33 1.0
## Q09                    0.61 0.36 0.64 1.0
## Q10        0.35             0.20 0.80 1.2
## Q11              0.76       0.65 0.35 1.1
## Q12  0.48                   0.46 0.54 1.6
## Q13        0.49             0.49 0.51 1.4
## Q14  0.32  0.38             0.42 0.58 2.0
## Q15                         0.33 0.67 2.9
## Q16  0.49                   0.46 0.54 1.3
## Q17              0.69       0.59 0.41 1.0
## Q18        0.56             0.57 0.43 1.5
## Q19                    0.37 0.26 0.74 1.5
## Q20  0.48                   0.28 0.72 1.6
## Q21  0.61                   0.48 0.52 1.1
## Q22                    0.48 0.26 0.74 1.4
## Q23                    0.34 0.11 0.89 1.6
## 
##                        PA1  PA3  PA4  PA2
## SS loadings           3.10 2.53 2.37 1.61
## Proportion Var        0.13 0.11 0.10 0.07
## Cumulative Var        0.13 0.24 0.35 0.42
## Proportion Explained  0.32 0.26 0.25 0.17
## Cumulative Proportion 0.32 0.59 0.83 1.00
## 
##  With factor correlations of 
##       PA1   PA3   PA4   PA2
## PA1  1.00  0.50  0.55 -0.40
## PA3  0.50  1.00  0.47 -0.33
## PA4  0.55  0.47  1.00 -0.22
## PA2 -0.40 -0.33 -0.22  1.00
## 
## Mean item complexity =  1.4
## Test of the hypothesis that 4 factors are sufficient.
## 
## The degrees of freedom for the null model are  253  and the objective function was  7.93 with Chi Square of  19534.27
## The degrees of freedom for the model are 167  and the objective function was  0.43 
## 
## The root mean square of the residuals (RMSR) is  0.02 
## The df corrected root mean square of the residuals is  0.03 
## 
## The harmonic number of observations is  2474 with the empirical chi square  779.09  with prob <  1e-79 
## The total number of observations was  2474  with Likelihood Chi Square =  1065.48  with prob <  1e-130 
## 
## Tucker Lewis Index of factoring reliability =  0.929
## RMSEA index =  0.047  and the 90 % confidence intervals are  0.044 0.049
## BIC =  -239.39
## Fit based upon off diagonal values = 0.99
## Measures of factor score adequacy             
##                                                    PA1  PA3  PA4  PA2
## Correlation of (regression) scores with factors   0.91 0.91 0.92 0.83
## Multiple R square of scores with factors          0.83 0.82 0.85 0.70
## Minimum correlation of possible factor scores     0.66 0.64 0.71 0.39

- Drop items 3, 14 (loads onto multiple factors) and 15 (no loadings) for oblimin rotation

# after Q03 and Q14 are dropped

d5 <- d2[,c(1, 2,    4, 5,6, 7, 8, 9, 10, 11, 12, 13,     16, 17, 18, 19, 20, 21, 22, 23)]

M9 <- fa(d5, nfactors = 4, fm = "pa", SMC = TRUE, rotate = "oblimin") 
print.psych(M9, cut=.3)
## Factor Analysis using method =  pa
## Call: fa(r = d5, nfactors = 4, rotate = "oblimin", SMC = TRUE, fm = "pa")
## Standardized loadings (pattern matrix) based upon correlation matrix
##       PA1   PA4   PA3   PA2   h2   u2 com
## Q01  0.53                   0.40 0.60 1.3
## Q02                    0.51 0.28 0.72 1.1
## Q04  0.55                   0.42 0.58 1.1
## Q05  0.48                   0.32 0.68 1.1
## Q06              0.81       0.61 0.39 1.0
## Q07              0.49       0.51 0.49 1.6
## Q08        0.86             0.67 0.33 1.0
## Q09                    0.59 0.35 0.65 1.0
## Q10              0.33       0.19 0.81 1.3
## Q11        0.75             0.65 0.35 1.1
## Q12  0.50                   0.46 0.54 1.5
## Q13              0.48       0.49 0.51 1.5
## Q16  0.52                   0.45 0.55 1.2
## Q17        0.68             0.58 0.42 1.1
## Q18              0.55       0.58 0.42 1.5
## Q19                    0.36 0.25 0.75 1.6
## Q20  0.51                   0.29 0.71 1.5
## Q21  0.64                   0.49 0.51 1.0
## Q22                    0.50 0.28 0.72 1.3
## Q23                    0.33 0.11 0.89 1.6
## 
##                        PA1  PA4  PA3  PA2
## SS loadings           2.83 2.18 2.06 1.31
## Proportion Var        0.14 0.11 0.10 0.07
## Cumulative Var        0.14 0.25 0.35 0.42
## Proportion Explained  0.34 0.26 0.25 0.16
## Cumulative Proportion 0.34 0.60 0.84 1.00
## 
##  With factor correlations of 
##       PA1   PA4   PA3   PA2
## PA1  1.00  0.56  0.51 -0.37
## PA4  0.56  1.00  0.45 -0.18
## PA3  0.51  0.45  1.00 -0.31
## PA2 -0.37 -0.18 -0.31  1.00
## 
## Mean item complexity =  1.3
## Test of the hypothesis that 4 factors are sufficient.
## 
## The degrees of freedom for the null model are  190  and the objective function was  6.48 with Chi Square of  15970.51
## The degrees of freedom for the model are 116  and the objective function was  0.33 
## 
## The root mean square of the residuals (RMSR) is  0.03 
## The df corrected root mean square of the residuals is  0.03 
## 
## The harmonic number of observations is  2474 with the empirical chi square  605.58  with prob <  2.6e-67 
## The total number of observations was  2474  with Likelihood Chi Square =  812.47  with prob <  5.4e-105 
## 
## Tucker Lewis Index of factoring reliability =  0.928
## RMSEA index =  0.049  and the 90 % confidence intervals are  0.046 0.052
## BIC =  -93.91
## Fit based upon off diagonal values = 0.99
## Measures of factor score adequacy             
##                                                    PA1  PA4  PA3  PA2
## Correlation of (regression) scores with factors   0.91 0.92 0.90 0.81
## Multiple R square of scores with factors          0.83 0.85 0.81 0.65
## Minimum correlation of possible factor scores     0.65 0.70 0.61 0.30

8. Results

a. factor loadings

fa.diagram(M8, main = "R Anxiety Questionnaire")

b. Are factors reliable?

c. Do factors make sense?

in sum i chose to go with oblimin because the factor groups make more sense than with promax.