make.keys {psych} | R Documentation |
When scoring items by forming composite scales either from the raw data using score.items
or from the correlation matrix using cluster.cor
, it is necessary to create a keys matrix. This is just a short cut for doing so. The keys matrix is a nvar x nscales matrix of -1,0, 1 and defines the membership for each scale.
make.keys(nvars, keys.list, key.labels = NULL, item.labels = NULL)
nvars |
Number of variables items to be scored |
keys.list |
A list of the scoring keys,one element for each scale |
key.labels |
Labels for the scales can be specified here, or in the key.list |
item.labels |
Typically, just the colnames of the items data matrix. |
There are two ways to create keys for the score.items
function. One is to laboriously do it in a spreadsheet and then copy them into R. The other is to just specify them by item number in a list.
keys |
a nvars x nkeys matrix of -1, 0, or 1s describing how to score each scale. nkeys is the length of the keys.list |
data(attitude) key.list <- list(all=c(1,2,3,4,-5,6,7), first=c(1,2,3), last=c(4,5,6,7)) keys <- make.keys(7,key.list,item.labels = colnames(attitude)) keys scores <- score.items(keys,attitude) scores data(bfi) keys.list <- list(agree=c(-1,2:5),conscientious=c(6:8,-9,-10),extraversion=c(-11,-12,13:15),neuroticism=c(16:20),openness = c(21,-22,23,24,-25)) keys <- make.keys(25,keys.list,item.labels=colnames(bfi)[1:25]) scores <- score.items(keys,bfi[,1:25]) summary(scores)