R version 3.0.2 (2013-09-25) -- "Frisbee Sailing" Copyright (C) 2013 The R Foundation for Statistical Computing Platform: i686-pc-linux-gnu (32-bit) R is free software and comes with ABSOLUTELY NO WARRANTY. You are welcome to redistribute it under certain conditions. Type 'license()' or 'licence()' for distribution details. R is a collaborative project with many contributors. Type 'contributors()' for more information and 'citation()' on how to cite R or R packages in publications. Type 'demo()' for some demos, 'help()' for on-line help, or 'help.start()' for an HTML browser interface to help. Type 'q()' to quit R. > x <- array(list(3,3,4,3,3,3,3,3,3,2,2,4,3,3,4,3,3,4,3,5,3,3,3,5,1,3,3,2,3,1,1,1,1,1,1,2,5,5,5,4,5,4,4,4,3,3,3,2,3,1,1,1,3,1,3,4,3,3,2,3,3,3,2,3,3,3,4,3,4,3,5,4,3,3,2,2,2,4,3,2,4,4,2,5,3,3,3,5,4,4,3,4,4,4,5,4,3,3,2,4,3,5,1,5),dim=c(4,26),dimnames=list(c('Q1','Q2','Q3','Q4'),1:26)) > y <- array(NA,dim=c(4,26),dimnames=list(c('Q1','Q2','Q3','Q4'),1:26)) > for (i in 1:dim(x)[1]) + { + for (j in 1:dim(x)[2]) + { + y[i,j] <- as.numeric(x[i,j]) + } + } > #'GNU S' R Code compiled by R2WASP v. 1.2.291 () > #Author: root > #To cite this work: Wessa P., 2012, Cronbach alpha (v1.0.2) in Free Statistics Software (v$_version), Office for Research Development and Education, URL http://www.wessa.net/rwasp_cronbach.wasp/ > #Source of accompanying publication: > # > library(psych) > z <- t(y) > (r <- alpha(z)) Reliability analysis Call: alpha(x = z) raw_alpha std.alpha G6(smc) average_r mean sd 0.76 0.77 0.73 0.45 3.1 0.86 Reliability if an item is dropped: raw_alpha std.alpha G6(smc) average_r Q1 0.69 0.69 0.62 0.43 Q2 0.66 0.68 0.60 0.42 Q3 0.74 0.74 0.66 0.49 Q4 0.71 0.72 0.64 0.47 Item statistics n r r.cor r.drop mean sd Q1 26 0.79 0.68 0.60 3.1 0.91 Q2 26 0.80 0.71 0.63 3.0 1.11 Q3 26 0.73 0.58 0.49 2.8 1.22 Q4 26 0.75 0.64 0.54 3.3 1.23 Non missing response frequency for each item 1 2 3 4 5 miss Q1 0.08 0.04 0.65 0.15 0.08 0 Q2 0.15 0.04 0.50 0.23 0.08 0 Q3 0.15 0.23 0.35 0.15 0.12 0 Q4 0.08 0.19 0.23 0.31 0.19 0 > > #Note: the /var/fisher/rcomp/createtable file can be downloaded at http://www.wessa.net/cretab > load(file="/var/fisher/rcomp/createtable") > > a<-table.start() > a<-table.row.start(a) > a<-table.element(a,'Cronbach Alpha and Related Statistics',5,TRUE) > a<-table.row.end(a) > a<-table.row.start(a) > a<-table.element(a,'Items',1,TRUE) > a<-table.element(a,'Cronbach Alpha',1,TRUE) > a<-table.element(a,'Std. Alpha',1,TRUE) > a<-table.element(a,'G6(smc)',1,TRUE) > a<-table.element(a,'Average R',1,TRUE) > a<-table.row.end(a) > a<-table.row.start(a) > a<-table.element(a,'All itmes',header=TRUE) > a<-table.element(a,round(r$total['raw_alpha'],4)) > a<-table.element(a,round(r$total['std.alpha'],4)) > a<-table.element(a,round(r$total['G6(smc)'],4)) > a<-table.element(a,round(r$total['average_r'],4)) > a<-table.row.end(a) > n = length(z[1,]) > for (i in 1:n) { + a<-table.row.start(a) + a<-table.element(a,paste(colnames(z)[i],' excluded',sep=''),header=TRUE) + a<-table.element(a,round(r$alpha.drop[i,'raw_alpha'],4)) + a<-table.element(a,round(r$alpha.drop[i,'std.alpha'],4)) + a<-table.element(a,round(r$alpha.drop[i,'G6(smc)'],4)) + a<-table.element(a,round(r$alpha.drop[i,'average_r'],4)) + a<-table.row.end(a) + } > a<-table.end(a) > table.save(a,file="/var/fisher/rcomp/tmp/15rat1384764779.tab") > > > > proc.time() user system elapsed 0.419 0.091 0.482