Abstract
This article is a literature review which seeks to answer four questions: 1) What is washback? 2) How does washback work? 3) How can we promote positive washback? 4) How can we investigate washback? Building on the 'Washback Hypothesis' proposed by Alderson and Wall, and suggestions from Hughes, the article proposes a model that identifies participants, processes and products which may influence, or be influenced by, washback. Strategies for investigating wash back are also discussed.