Summarizing and Visualizing Item Response Data
Summarizing and visualizing "itemresp" data objects.
## S3 method for class 'itemresp'
summary(object, items = NULL, abbreviate = FALSE,
mscale = TRUE, simplify = TRUE, sep = " ", ...)
## S3 method for class 'itemresp'
plot(x, xlab = "", ylab = "", items = NULL,
abbreviate = FALSE, mscale = TRUE, sep = "\n", off = 2, axes = TRUE,
names = TRUE, srt = 45, adj = c(1.1, 1.1), ...)object, x |
an object of class |
items |
character or integer for subsetting the items to be summarized/visualized. By default, all items are used. |
abbreviate |
logical or integer. Should scale labels be abbreviated? Alternatively, an integer with the desired abbreviation length. The default is some heuristic based on the length of the labels. |
mscale |
logical. Should mscale values be used for printing/plotting?
If |
simplify |
logical. Should the summary table be collapsed into a matrix or returned as a list? |
sep |
character. A character for separating item labels from their corresponding scale labels (if any). |
xlab, ylab, off, axes, ... |
arguments passed to |
names |
logical or character. If |
srt, adj |
numeric. Angle ( |
The plot method essentially just calls summary (passing on most further
arguments) and then visualizes the result as a spineplot.
## summary/visualization for verbal aggression data
data("VerbalAggression", package = "psychotools")
r <- itemresp(VerbalAggression$resp[, 1:6])
mscale(r) <- c("no", "perhaps", "yes")
summary(r)
plot(r)
## modify formatting of mscale
summary(r, abbreviate = 1)
summary(r, mscale = FALSE)
## illustration for varying mscale across items
## merge with additional random binary response
b <- itemresp(rep(c(-1, 1), length.out = length(r)),
mscale = c(-1, 1), labels = "Dummy")
rb <- merge(r[, 1:2], b)
head(rb, 2)
## summary has NAs for non-existent response categories
summary(rb)
summary(rb, mscale = FALSE)
plot(rb, srt = 25)
plot(rb, mscale = FALSE)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.