The tests provide parents and schools with an understanding of how individual students are performing at the time of tests.
This is such a hard thing to communicate. It is easy to read ‘performing’ as some sort of exact since, such as Johnny got 33 out of 40 in the recent test on whatever. The problem though is that NAPLAN is not ‘exact’ either at the time or as a measurement of growth. This is highlighted by Richard Olsen in his look at the limitations:
In practice, NAPLAN relative growth is a so unreliable that I cannot believe that it is a suitable measure and I would personally discourage anyone from using it. The narrow range of questions that define average growth, compounded by the error inherent to NAPLAN’s testing method make it an extremely unreliable measure.
I think that Margaret Wu captures this best when she explains:
In summary, we would say that a NAPLAN test only provides an indicative level of the performance of a student: whether the student is struggling, on track, or performing above average. The NAPLAN tests do not provide fine grading of students by their performance levels because of the large uncertainties associated with the ability measures.