Table 2 Results data example. Parameter estimates (posterior means) of the multilevel model for the example ‘Trait Anxiety’ data with a random intercept using the IRT-based plausible values technique and the CTT-based scores as outcome variables

Mean^c

SD

Mean^c

SD

Fixed effect

γ Intercept

0.018

0.043

0.015

0.045

Random Effects

Between individual (level-2)

τ² Intercept

0.733

0.067

0.685

0.074

Within individual (level-1)

σ² Residual variance

0.294

0.030

0.357

0.042

Intra Class Correlation

ρ

0.287

0.343