Chapter 9 Secondary data analysis & pre-registration of longitudinal analyses

9.1 What is a preregistration?

A document outlining the planned analyses

• i.e., we preregister before we start playing with data.

Why?

• We develop hypotheses before we analyze the data.
• Preregistrations serve as a document of what our expectations and plans were.
• Identify which analyses are based on theory and which are based on the data.

Cycle of scientific method with preregistration at the hypothesis step:

From Munafò et al. (2017). Preregistration can help guard against issues of p-hacking, HARKing, and publication bias.

I would argue that a really good preregistration guards against ALL of these issues.

9.2 But don’t do it for science…

… do it for you!

• Focus on the research question.
• Increase credibilityin your results.
• Stake your claim on an idea.
• Not a waste of time. A reordering of steps.