Imagine that during an evening while you are out at the theater, your home is broken into and several personal items are stolen. This sudden event, in addition to having practical and possibly emotional consequences, is going to lead to changes in your beliefs and predictions about the future. Whereas you may have previously thought that your home was secure, you may now believe, on the basis of this one event, that it is rather likely that your home will be burgled again.

In the terms of inductive reasoning, you may well see similarities between one case – your home on this particular evening – and future cases – that is, your home on other, future evenings – leading you to project a predicate – being burgled – from the one case to the others. Of course, carrying out this sort of inductive reasoning would be more complicated, because there are the many past cases of evenings on which your home has not been burgled, and these cases too seem to have implications for the future. In addition, other information may be useful, such as whether or not nearby homes have been burgled recently. It seems that due to the similarity in location, knowing the history of other homes would help you to predict the safety of your own home.

Books on induction are rare; in fact, you are holding in your hands the first book devoted solely to the psychology of inductive reasoning in twenty years. And yet induction is a central topic in cognitive science, fundamental to learning, discovery, and prediction. We make inductive inferences every time we use what we already know to deal with novel situations. For example, wherever you found this book – in your university library, online, or in an academic bookshop – before picking it from the shelf or clicking on a link, you will have made some inductive inferences. Amongst other things, these inferences will have concerned the book's likely content given its title, its editors, its publisher, or its cover. Common to all of these inferences will have been the use of what you already know – about us, or the topic suggested by our title, or Cambridge University Press – to make predictions about the likely attributes of this book.

It is not only in publishers' catalogues that attention to induction has been scant. Despite its obvious centrality to an understanding of human cognition and behaviour, much less work has been carried out by psychologists on induction than on deduction, or logical reasoning. As a consequence, although there have been several edited collections of work on deduction and on decision making (Connolly, Arkes, & Hammond, 2000; Leighton & Sternberg, 2004; Gilovich, Griffin, & Kahneman, 2002; Manktelow & Chung, 2004), to the best of our knowledge there has never previously been an edited collection of papers on the psychology of inductive inference.

Why study induction, and indeed, why should there be a whole book devoted to the study of induction? The first reason is that inductive reasoning corresponds to probabilistic, uncertain, approximate reasoning, and as such, it corresponds to everyday reasoning. On a daily basis we draw inferences such as how a person will probably act, what the weather will probably be like, and how a meal will probably taste, and these are typical inductive inferences. So if researchers want to study a form of reasoning that is actually a pervasive cognitive activity, then induction is of appropriate interest.

The second reason to study induction is that it is a multifaceted cognitive activity. It can be studied by asking young children simple questions involving cartoon pictures, or it can be studied by giving adults a variety of complex verbal arguments and asking them to make probability judgments. Although induction itself is uncertain by nature, there is still a rich, and interesting, set of regularities associated with induction, and researchers are still discovering new phenomena.

Third, induction is related to, and it could be argued is central to, a number of other cognitive activities, including categorization, similarity judgment, probability judgment, and decision making. For example, much of the study of induction has been concerned with category-based induction, such as inferring that your next door neighbor sleeps on the basis that your neighbor is a human animal, even if you have never seen your neighbor sleeping. And as will be seen, similarity and induction are very closely related, many accounts of induction using similarity as their main currency (Heit & Hayes, 2005).

Finally, the study of induction has the potential to be theoretically revealing.