ABSTRACT
Imagine the situation of a researcher who conducts a study of the effectiveness of an intervention that she has developed to improve children's vocabulary. She has attended to all the sources of bias that feature in earlier chapters and has run a well-powered randomized controlled trial. But at the end of the day, the results are disappointing. Mean vocabulary scores of intervention and control groups are closely similar, with no evidence that the intervention was effective. In fact, failure to publish null results from well-designed studies is a massive problem for any field. This is because science is cumulative. A well-designed RCT included 216 school-aged children divided between four arms: individualized language intervention by a speech-language pathologist; computer-assisted language intervention; Fast Forword-Language – a commercial intervention designed to remediate a putative auditory processing deficit thought to cause language problems; an academic enrichment program which did not target language skills.
