library(foreign)
data <- read.spss("613_psychometrics_extraversion.sav", to.data.frame = TRUE)
## Warning: 613_psychometrics_extraversion.sav: Unrecognized record type 7,
## subtype 18 encountered in system file
## re-encoding from UTF-8
head(data)
## v1 v2 v3 v4 v5 v6 v7 v8 v2r v4r v6r bfie bfiepomp
## 1 4 2 5 3 5 2 4 4 4 3 4 4.125 78.12
## 2 4 1 4 1 5 2 4 4 5 5 4 4.375 84.38
## 3 4 1 4 1 4 2 4 4 5 5 4 4.250 81.25
## 4 4 2 2 3 4 3 3 4 4 3 3 3.375 59.38
## 5 4 4 4 1 4 2 4 4 2 5 4 3.875 71.88
## 6 4 1 3 3 5 2 4 4 5 3 4 4.000 75.00
data <- data[, 1:8]
library(psych)
alpha(data)
## Warning: Some items were negatively correlated with total scale and were
## automatically reversed.
##
## Reliability analysis
## Call: alpha(x = data)
##
## raw_alpha std.alpha G6(smc) average_r S/N ase mean sd
## 0.75 0.75 0.75 0.27 3 0.018 3.9 0.53
##
## lower alpha upper 95% confidence boundaries
## 0.71 0.75 0.78
##
## Reliability if an item is dropped:
## raw_alpha std.alpha G6(smc) average_r S/N alpha se
## v1 0.73 0.73 0.72 0.28 2.7 0.020
## v2- 0.72 0.72 0.71 0.27 2.6 0.020
## v3 0.71 0.72 0.70 0.27 2.5 0.020
## v4- 0.71 0.72 0.70 0.26 2.5 0.020
## v5 0.70 0.70 0.69 0.25 2.4 0.021
## v6- 0.73 0.73 0.72 0.28 2.7 0.019
## v7 0.74 0.74 0.73 0.29 2.9 0.019
## v8 0.74 0.74 0.73 0.29 2.9 0.019
##
## Item statistics
## n r r.cor r.drop mean sd
## v1 1000 0.58 0.48 0.42 3.7 0.89
## v2- 1000 0.63 0.56 0.47 4.2 0.84
## v3 1000 0.64 0.57 0.50 4.1 0.79
## v4- 1000 0.64 0.58 0.49 4.0 0.95
## v5 1000 0.70 0.66 0.57 4.1 0.82
## v6- 1000 0.58 0.49 0.42 3.6 1.07
## v7 1000 0.53 0.41 0.34 4.0 0.88
## v8 1000 0.53 0.41 0.35 3.7 0.77
##
## Non missing response frequency for each item
## 1 2 3 4 5 miss
## v1 0.01 0.10 0.23 0.52 0.14 0
## v2 0.42 0.45 0.08 0.05 0.01 0
## v3 0.01 0.04 0.13 0.54 0.28 0
## v4 0.35 0.42 0.15 0.06 0.02 0
## v5 0.01 0.04 0.11 0.50 0.34 0
## v6 0.22 0.41 0.20 0.14 0.03 0
## v7 0.01 0.06 0.12 0.49 0.32 0
## v8 0.01 0.07 0.20 0.61 0.11 0
data <- read.spss("613_psychometrics_extraversionICC.sav", to.data.frame = TRUE)
## Warning: 613_psychometrics_extraversionICC.sav: Unrecognized record type
## 7, subtype 18 encountered in system file
## re-encoding from UTF-8
head(data)
## SID R1 R2 R3 R4 R5 R6 R7 R8 R_avg
## 1 4 3 0 0 0 0 0 0 2 0.625
## 2 5 3 0 0 0 0 0 0 2 0.625
## 3 15 3 0 0 0 0 0 0 2 0.625
## 4 17 3 0 0 0 0 0 0 2 0.625
## 5 21 3 0 0 0 0 0 0 2 0.625
## 6 28 3 0 0 0 0 0 0 2 0.625
data <- data[, 2:9]
ICC(data)
## Call: ICC(x = data)
##
## Intraclass correlation coefficients
## type ICC F df1 df2 p lower bound upper bound
## Single_raters_absolute ICC1 0.42 6.7 39 280 0 0.29 0.56
## Single_random_raters ICC2 0.45 27.6 39 273 0 0.21 0.65
## Single_fixed_raters ICC3 0.77 27.6 39 273 0 0.68 0.85
## Average_raters_absolute ICC1k 0.85 6.7 39 280 0 0.77 0.91
## Average_random_raters ICC2k 0.87 27.6 39 273 0 0.68 0.94
## Average_fixed_raters ICC3k 0.96 27.6 39 273 0 0.94 0.98
##
## Number of subjects = 40 Number of Judges = 8