Description

Artificial data set of 70 subjects with 5 items, 4 time points and 3 groups for LLRA.

Usage

Format

A data frame with 70 observations of 21 variables.

t1.I1

Answers to item 1 at time point 1

t1.I2

Answers to item 2 at time point 1

t1.I3

Answers to item 3 at time point 1

t1.I4

Answers to item 4 at time point 1

t1.I5

Answers to item 5 at time point 1

t2.I1

Answers to item 1 at time point 2

t2.I2

Answers to item 2 at time point 2

t2.I3

Answers to item 3 at time point 2

t2.I4

Answers to item 4 at time point 2

t2.I5

Answers to item 5 at time point 2

t3.I1

Answers to item 1 at time point 3

t3.I2

Answers to item 2 at time point 3

t3.I3

Answers to item 3 at time point 3

t3.I4

Answers to item 4 at time point 3

t3.I5

Answers to item 5 at time point 3

t4.I1

Answers to item 1 at time point 4

t4.I2

Answers to item 2 at time point 4

t4.I3

Answers to item 3 at time point 4

t4.I4

Answers to item 4 at time point 4

t4.I5

Answers to item 5 at time point 4

group

The group membership

Details

This is a data set as described in Hatzinger and Rusch (2009). 5 items were measured at 4 time points (in columns). Each persons answers to the items are recorded in the rows. There are 2 treatment groups and a control group. Treatment group 2 has size, 10, treatment group 1 has size 20 and the control group has size 40. Item 1 is dichotomous, all others are polytomous. Item 2, 3, 4 and 5 have 3, 4, 5, 6 categories respectively.

References

Hatzinger, R. and Rusch, T. (2009) IRT models with relaxed assumptions in eRm: A manual-like instruction. Psychology Science Quarterly, 51, pp. 87–120.

Examples