data.pars1.rasch {sirt}

Item Parameters for Three Studies Obtained by 1PL and 2PL Estimation

Description

The datasets contain item parameters to be prepared for linking using the function linking.haberman.

Usage

data(data.pars1.rasch)
data(data.pars1.2pl)

Format

• The format of data.pars1.rasch is:

  'data.frame': 22 obs. of 4 variables:
$ study: chr "study1" "study1" "study1" "study1" ...
$ item : Factor w/ 12 levels "M133","M176",..: 1 2 3 4 5 1 6 7 3 8 ...
$ a : num 1 1 1 1 1 1 1 1 1 1 ...
$ b : num -1.5862 0.40762 1.78031 2.00382 0.00862 ...

  Item slopes a are fixed to 1 in 1PL estimation. Item difficulties are denoted by b.
  

• The format of data.pars1.2pl is:

  'data.frame': 22 obs. of 4 variables:
$ study: chr "study1" "study1" "study1" "study1" ...
$ item : Factor w/ 12 levels "M133","M176",..: 1 2 3 4 5 1 6 7 3 8 ...
$ a : num 1.238 0.957 1.83 1.927 2.298 ...
$ b : num -1.16607 0.35844 1.06571 1.17159 0.00792 ...