make.keys {psych}R Documentation

Create a keys matrix for use by score.items or cluster.cor

Description

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.

Usage

make.keys(nvars, keys.list, key.labels = NULL, item.labels = NULL)

Arguments

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.

Details

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.

Value

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

See Also

score.items, cluster.cor

Examples

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)


[Package psych version 1.3.2 Index]