Score a test by converting response patterns to binary data
The key2binary function will convert response pattern data to a
dichotomous format, given a response key.
key2binary(fulldata, key, score_missing = FALSE)
fulldata |
an object of class |
key |
a vector or matrix consisting of the 'correct' response to the items. Each
value/row corresponds to each column in |
score_missing |
logical; should missing data elements be returned as incorrect (i.e., 0)?
If |
Returns a numeric matrix with all the response patterns in dichotomous format
Phil Chalmers rphilip.chalmers@gmail.com
Chalmers, R., P. (2012). mirt: A Multidimensional Item Response Theory Package for the R Environment. Journal of Statistical Software, 48(6), 1-29. doi: 10.18637/jss.v048.i06
data(SAT12)
head(SAT12)
key <- c(1,4,5,2,3,1,2,1,3,1,2,4,2,1,5,3,4,4,1,4,3,3,4,1,3,5,1,3,1,5,4,5)
dicho.SAT12 <- key2binary(SAT12, key)
head(dicho.SAT12)
# multiple scoring keys
key2 <- cbind(c(1,4,5,2,3,1,2,1,3,1,2,4,2,1,5,3,4,4,1,4,3,3,4,1,3,5,1,3,1,5,4,5),
c(2,3,NA,1,rep(NA, 28)))
dicho.SAT12 <- key2binary(SAT12, key2)
# keys from raw character responses
resp <- as.data.frame(matrix(c(
"B","B","D","D","E",
"B","A","D","D","E",
"B","A","D","C","E",
"D","D","D","C","E",
"B","C","A","D","A"), ncol=5, byrow=TRUE))
key <- c("B", "D", "D", "C", "E")
d01 <- key2binary(resp, key)
head(d01)
# score/don't score missing values
resp[1,1] <- NA
d01NA <- key2binary(resp, key) # without scoring
d01NA
d01 <- key2binary(resp, key, score_missing = TRUE) # with scoring
d01Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.