descript {ltm} | R Documentation |
Computes the percentages of positive and negative responses for each item, as well as the pairwise associations between items (see Details for more info).
descript(data, n.print = 10, B = 1000)
data |
a matrix or data.frame containing the manifest variables. |
n.print |
numeric indicating the number of pairwise associations with the highest p-values to be printed. |
B |
the B argument of chisq.test() . |
Before an analysis with latent variable models, it is useful to inspect the data for evidence of
positive correlations. In the case of binary data, this ad hoc check can be performed by constructing
the 2 by 2 contingency tables for all possible pairs of items and examine the Chi-squared
p-values. In case any expected frequencies are smaller than 5, simulate.p.value
is turned to
TRUE
in chisq.test()
, using B
resamples.
An object of class descript
with components,
sample |
a numeric vector of length 2, with elements the number of items and the number of sample units. |
perc |
a numeric matrix containing the percentages of positive and negative responses for each item. |
items |
a numeric matrix containing the frequencies for the total scores. |
pw.ass |
a matrix containing the p-values for the pairwise association between the items. |
n.print |
the value of the n.print argument. |
name |
the name of argument data . |
Dimitris Rizopoulos dimitris.rizopoulos@med.kuleuven.be
## Descriptives for Wirs data: descript(Wirs, 3)