he authors refer to our work (McPhillips, Hepper, & Mulhern (2000)) in the introduction and suggest that it provides evidence of absence of the Hawthorne effect in evaluative studies of exercise-based interventions. This is inaccurate. Firstly, the effect is more accurately described as a placebo effect and, secondly, there was strong evidence of a placebo effect for the placebocontrol group used in our study. They made greater progress in reading, despite very significant reading difficulties, (30 months behind in reading age), than the children reported in Reynolds et al. achieved in the year prior to intervention (see later).
The authors go on to reject the use of a placebo-control group on the basis that it would have been unethical. This is contrary to conventional evaluative procedure and the reverse argument is the standard ethical position. The use of a placebo-control doing a different exercise programme is an ethical imperative particularly where the study may influence the type of intervention that vulnerable parents of children with difficulties choose to pursue. It is relatively easy to design placebo movements that have face-validity and that are as interesting as the experimental programme. There is also the possibility that the placebo-control group out-performs the experimental group and that 'intervention' minus the specific content of the experimental exercises is more effective.