Question

1: What is the sawtooth effect that may occur in forecasting? How does it happen, and how would an analyst remedy it in their forecast?

2: Why did we use the mid-point for the number of stores opened each year as our basis for forecasting sales?

Answer 1

1 The 'Sawtooth Effect' is a pattern of change caused by assessment reform. Specifically, performance on high stakes assessments is often adversely affected when that assessment undergoes reform, followed by improving performance over time.

There are several reasons to expect that the Sawtooth Effect would occur as a result of these reforms. Firstly, although the presence of the effect in the American literature does not necessarily imply the same for the UK, the fact that core skills such as reading and mathematics seem to be affected in this manner (eg Koretz et al., 1991) may suggest that many UK assessments could also follow the same trends, as these core skills will be important for most, if not all, general assessments. Secondly, as discussed previously, high-stakes accountability testing (which applies to GCSEs and AS / A levels) means that students and teachers are increasingly motivated to achieve high outcomes, and are likely to direct their teaching / learning focus towards the specifics of each test to ensure the best possible outcomes.