
## Contents

| 1          | Introduction                                             | 3   |    |
|------------|----------------------------------------------------------|-----|----|
| 2          | Natural Intelligence                                     | 5   |    |
| 2.1        | Human intelligence tests                                 |     | 5  |
| 2.2        | Animal intelligence tests                                |     | 7  |
| 2.3        | Desirable properties of an intelligence test             |     | 8  |
| 2.4        | Static vs. dynamic tests                                 |     | 9  |
| 2.5        | Theories of human intelligence                           | 9   |    |
| 2.6        | Ten definitions of human intelligence                    |     | 10 |
| 2.7        | More definitions of human intelligence                   |     | 12 |
| 3          | A Definition of Machine Intelligence                     | 15  |    |
| 3.1        | Basic agent-environment framework                        | 15  |    |
| 3.2        | Formal agent-environment framework                       |     | 17 |
| 3.3        | A formal definition of machine intelligence              |     | 20 |
| 3.4        | Universal intelligence of various agents                 |     | 24 |
| 3.5        | Properties of universal intelligence                     | 27  |    |
| 4          | Definitions and Tests of Machine Intelligence            | 30  |    |
| 4.1        | Informal definitions of machine intelligence             |     | 31 |
| 4.2        | Formal definitions and tests of machine intelligence     |     | 33 |
| 4.3        | Comparison of machine intelligence tests and definitions |     | 38 |
| 5          | Discussion and Conclusions                               | 39  |    |
| 5.1        | Constructing a test of universal intelligence            | 39  |    |
| 5.2        | Response to common criticisms                            |     | 40 |
| 5.3        | Conclusion                                               | 43  |    |
| References | 43                                                       |     |    |
