Background: In this study Mark Griffiths is investigating some of the cognitive differences between regular and non-regular gamblers. In particular he is interested in discovering whether regular fruit machine payers think differently to non-regular players. That is, whether regular fruit machine players display cognitive distortions. This particular study is interested in some of the cognitive biases that gamblers make which may encourage them to continue to gamble. Wagenaar argues that gamblers use a range of cognitive distortions called heuristics. Heuristics are a set of rules for solving problems. Griffiths noted that in terms of gambling, there are six important cognitive distortions that regular gamblers use: Illusion of control: This is the belief that we can control random events, such a choosing the winning lottery numbers. Flexible attributions: This is where gamblers attribute (explain) their own wins in terms of skill and their losses in terms of some external factor such as bad luck. Representativeness: This is where we make the mistake of believing that random events have a pattern, therefore believing that the probability of winning will increase with the length of an ongoing run of losses. Availability bias: This occurs when we are more likely to remember the times we or others win rather than lose. Illusory correlations: There are superstitious beliefs when people believe that two variables are related when in fact they are not. Fixation on absolute frequency: This occurs when gamblers measure their success using the absolute rather than the relative frequency of wins. The above heuristics or biases give some insights into why gamblers do not learn from their past losses and can help to explain irrational gambling behaviour. Although Griffiths does note that these heuristics cannot be used to predict behaviour because it is not possible to know which heuristics gamblers will choose to use on any specific occasion.