Errors: What are they and how significant are they?

Errors in educational research and measurement arise from four main sources: (1) errors associated with the characteristic being measured or intrinsic errors, (2) errors arising from the instrument being used or instrumental errors, (3) errors involved in the act of measurement or observational errors, and (4) errors arising from the process of sampling or sampling errors. The word 'error' has many meanings. The most common meaning is concerned with the idea of a ' mistake' which does not apply in this context. A further meaning is concerned with 'the difference between an observed or estimated numerical result and the true or exact one'. However, in educational research the 'true value' is both unknown and unknowable and this meaning does not apply. This paper is concerned with the examination of errors in several recent Australian research studies