Insufficient effort responding (IER) refers to a lack of effort when answering survey or questionnaire items. Such items typically offer more than two ordered response categories, with Likert-type scales as the most prominent example. The underlying assumption is that the successive categories reflect increasing levels of the latent variable…

The attitude of teachers towards inclusive education is a key issue for the success of inclusive education. Many studies have been designed to assess teachers' attitudes, but none have looked at the bias caused by teachers' non-response to questionnaires on their attitudes. Non-response biases are difficult to identify because it is impossible to…