Types of Research
This useful book provides a thorough overview of types of research, what they can and cannot find out, and issues for implementation.
Nick Hassey raises questions about the use of RCTs in educational research, suggesting that many common assumptions amongst educators about this approach may be incorrect. The ensuing comments on the post provide an informative discussion.
Recommended reading as an introduction to single-subject research, not least because it shows how to evaluate research reports based on this approach, and how to use it to document evidence-based practice.
This fairly technical paper discusses the benefits and drawbacks of the Alternating Treatments Design (ATD) as a way of studying the effects of two different interventions on the same individual. This design is one of the many ways in which research can be usefully pursued on a subject by subject basis rather than by comparing groups and making statistical and other inferences.