This article explains how ACER's PAT Adaptive tests function. For more information about the assessments themselves, refer to the additional articles about PAT Maths and PAT Reading.
PAT Adaptive assessments comprise numerous testlets – small blocks of 10–14 items each – at varying levels of difficulty and arranged across three stages. When completing a PAT Adaptive test, each student will respond to one testlet in each of the three stages.
A student’s entry testlet – the first block of items the student sees – is automatically assigned according to their estimated ability. If the student previously completed a PAT test in the same learning area within the preceding two years, that scale score is used to determine a suitably difficult starting point. The student’s year level is also considered to ensure that the entry level contains content that is appropriate to the student. If the student has not completed a PAT test previously, their entry testlet is assigned according to their current year level.
After completing a testlet at each stage, students are allocated another testlet, the difficulty of which is based on their performance to that point. Importantly, the calculation of the next testlet's difficulty accounts for any changes made to previous responses. So, an incorrect response in the first stage of the test may be changed to a correct response and this will be taken into account before the student is assigned a testlet for stage three.
This 'branching' mechanism is designed to elicit the maximum amount of information for estimating a student’s ability at each stage and across the test as a whole.
'Parallel' testlets at every stage and level mean that students completing a PAT Adaptive test in the same learning area for a second time will always be given different questions to those they have previously seen. Parallel testlets meet the same strand and difficulty requirements, ensuring that students are presented content at the appropriate level of challenge.