Section One: Introduction: How does anybody know anything? -- Purpose: what are we trying to do -- Assumptions: what we believe about how we know -- Section Two: Discovery and communication of research findings: where do errors come from? -- Observation: seeing is not believing -- Communication: writing adds other problems -- Interpretation: ... and then you read it -- Section Three: The nature of error: what kinds are there? -- Bias: a systematic error -- Noise: the other type of error -- Section Four: Factually accurate information: can you believe it? -- Subject matter: what is being studied? -- Measurement: how does it size up? -- Description: are the results summarized fairly? -- Relationships: more informative, but more difficult to understand -- Control: rival explanations ... is something else at work? -- Interference: are the results real ... or could thay have been caused by noise? -- Section Five: Useful information: should you apply it? -- Generality: do the results apply to you? -- Being practical: going beyond error -- Section Six: Applications: How to do evaluations -- A step-by-step guide for evaluation -- Questions to ask -- Practicing -- Sample evaluations -- Practice articles -- A final word -- Glossary