describe Understanding the fundamentals of biostatistics.

1. In deliberating their findings, the authors have overlooked a major threat to the validity of their estimates of exposure. Define and discuss this error. [Note: it is usually a concern only when studying exposures of this type].

2. What alternative education design should overcome this problem and why?

3. Rate the study's interior validity; low and medium or high. Debate this systematically in relation to the data and other evidence presented in this paper.

4. To whom may the outcomes be generalised? Describe your answer briefly.