Examining how motivation toward science contributes to omitting behaviours in the Italian PISA 2006 sample

•Motivation toward science in students omitting behaviour•Omitting behaviour and students' science achievement in PISA 2006•Individual differences in Italian students omitting behaviour

The present study explored the omitting behaviour of a sample of 15-year-old Italian students participating in a large-scale assessment, in relation to their scientific self-efficacy, scientific self-concept, enjoyment of science, general interest in science and instrumental motivation, taken as dimensions of their overall motivation to learn science. Statistical analysis was applied to the PISA 2006 data set collected from 21,773 15-year-old Italian students. The research aim was to evaluate the relation between missing responses and the Italian PISA 2006 science scores and to identify the presence of homogeneous subgroups of students displaying distinctive omitting behaviours. Cluster analysis identified three sub-groups of omitters: low, leavers and jumpers. Group membership was significantly related to a) different patterns and levels of student motivation to learn science and b) gender. The results also showed that Italian students' science achievement on PISA 2006 was negatively predicted by their rate of omissions. Furthermore, multinomial logistic regression analysis suggested that students' scientific self-efficacy and enjoyment of science had a significant effect on their omitting behaviours. In light of these findings, the implications for education and the value attributed to the PISA assessment are discussed.