Impact of Educational Test Features on Item Difficulties by the Linear Logistic Test Model

Daniela MARELLA
Carlo DI CHIACCHIO
Giuseppe BOVE

Keywords

Rasch Model, LLTM, Latent Regression LLTM

Abstract

The aim of the paper is to investigate the effect of item and person properties on item difficulties using the Linear Logistic Test Model (LLTM) and its extensions. The data under investigation are the Italy mathematics data from the Program for International Student Assessment (PISA) 2006. The information regarding the geographical macro-area (North-Italy versus South-Italy) has been used in the application as person property. Furthermore, the comparison on item properties effects between North-Italy versus South-Italy is performed fitting the LLTM for each geographical macro-area.