#NHAP LIEU
likert=file.choose()
datalikert=read.csv(likert,header = TRUE)
save(datalikert,file = "datelikert.rda")
attach(datalikert)
is.data.frame(datalikert)
## [1] TRUE
#C10
library(psych)
fa=data.frame(A1,A2,A3,A4,A5)
alpha(fa)
##
## Reliability analysis
## Call: alpha(x = fa)
##
## raw_alpha std.alpha G6(smc) average_r S/N ase mean sd median_r
## 0.93 0.94 0.95 0.74 14 0.0083 4.1 0.72 0.78
##
## 95% confidence boundaries
## lower alpha upper
## Feldt 0.91 0.93 0.95
## Duhachek 0.92 0.93 0.95
##
## Reliability if an item is dropped:
## raw_alpha std.alpha G6(smc) average_r S/N alpha se var.r med.r
## A1 0.96 0.96 0.97 0.86 25.2 0.0049 0.0057 0.87
## A2 0.90 0.91 0.91 0.71 9.7 0.0125 0.0270 0.67
## A3 0.90 0.91 0.91 0.71 9.7 0.0125 0.0270 0.67
## A4 0.91 0.92 0.92 0.73 11.1 0.0111 0.0361 0.72
## A5 0.90 0.91 0.91 0.70 9.5 0.0121 0.0277 0.67
##
## Item statistics
## n raw.r std.r r.cor r.drop mean sd
## A1 198 0.74 0.73 0.60 0.60 4.1 0.89
## A2 198 0.94 0.94 0.95 0.90 4.0 0.83
## A3 198 0.94 0.94 0.95 0.90 4.0 0.83
## A4 198 0.89 0.90 0.89 0.84 4.1 0.74
## A5 198 0.94 0.94 0.95 0.90 4.0 0.73
##
## Non missing response frequency for each item
## 2 3 4 5 miss
## A1 0.00 0.33 0.20 0.47 0
## A2 0.02 0.30 0.35 0.33 0
## A3 0.02 0.30 0.35 0.33 0
## A4 0.01 0.21 0.45 0.33 0
## A5 0.01 0.24 0.48 0.28 0