About the author Rob Williams is a chartered occupational psychologist with over twelve years' experience in the design and delivery of ability tests. Having worked for several of the UK's leading test pub- lishers, he has written many numeracy tests and presented his research at home and abroad. Today he heads up Rob Williams Assessment Ltd, an independent company specialising in assess- ment for recruitment. Rob has run hundreds of assessment centres for numerous public sector organisations and private companies ­ giving him valuable insight into how testing is used in a wide range of businesses. When he's not working, Rob enjoys spending time with his two young daughters, going to the