Although it appears late in this book, this is a core chapter about non-cooperative games. It studies extensive games, which are game trees with imperfect information. Typically, players do not always have full access to all the information which is relevant to their choices.

Quality is an important issue for the software industry, though there is a balance between cost and quality. Starting with a few examples of software failures, this chapter discusses the need for testing, and uses an example to demonstrate why heuristics are needed to test software. A seven-step approach to testing software is introduced: analysis, identifying test coverage items and test cases, verifying the test design, implementing and executing the tests, and interpreting the test results. Key concepts are defined as used throughout the book, with a reference to the key IEEE/ISO software testing standard.

Random testing presents three main chanllenges: the test oracle problem, the test data selection problem, and the problem of when to finish testing. These are discussed in detail, and unit-test and application-test examples are worked using a simple but effective solution to these.Barriers to full automation are presented along with an overview of more advanced types of random testing. Some of the limitations are examined through the introduction of faults.

Congestion means that a shared resource, such as a road, becomes more costly when more people use it. In a congestion game, multiple players decide on which resource to use, with the aim to minimize their cost. This interaction defines a game because the cost depends on what the other players do.

In this chapter we start with the systematic development of non-cooperative game theory. Its most basic model is the game in strategic form, the topic of this chapter. The available actions of each player, called strategies, are assumed as given. The players choose their strategies simultaneously and independently, and receive individual payoffs that represent their preferences for strategy profiles (combinations of strategies).

Testing with equivalence partitions introduces the reader to the first and simplest form of black-box and unit testing. First a worked example is used to demonstrate how to progress from a specification of the software to a fully automated test. The steps of the process are then examined in more detail, and the strengths and weaknesses examined through the introduction of faults into the software. The chapter ends, as do all the chapters which introduce new testing techniques, with notes for the experienced tester.

In this final chapter, we explain a new equilibrium concept called correlated equilibrium that is more general than Nash equilibrium. It allows for randomized actions of the players that depend on an external signal (like a traffic light) that is observed by the players (typically in different ways) so that their actions can be correlated.

Testing object-oriented software is a significant topic in its own right, and this chapter presents the user with the essential underlying test techniques: testing in class context, and inheritance testing. As in the previous chapters, a worked example is used to introduce the reader to the concepts, which are then subsequently discussed in more detail. The chapter then summarises some more advanced techniques; state-based testing, UML-based testing, and built-in testing. Some of the limitations are examined through the introduction of faults into the working code.