Module 10 · The science in depth · Conceptual framework

How to read a habit study

Study types, effect sizes, self-report and context — interpreting evidence.

7 min read · Level: Advanced · Free — no account needed to read

The problem it solves

How do you tell a strong habit finding from a weak one?

The concept

Study designs differ in what they can show. Randomised trials can suggest cause and effect; observational and diary studies show associations; meta-analyses pool many studies; qualitative studies describe experiences. Each is useful for different questions.

Look at the size of the effect, not just whether one was found. A “significant” result can be tiny. Look at who was studied (students? patients? a few dozen people?), what was measured (self-report? behaviour?) and for how long.

Context matters in behaviour change. A technique that worked for gym-goers in one country may work differently for students elsewhere. That’s why personal experiments — carefully done — are a sensible next step.

Why it matters

Evidence labels in this lab — supported by multiple studies, research-supported, mixed, emerging — come from exactly these questions.

Conceptual framework: A way of organising ideas that helps you think clearly. It describes rather than predicts, so it is judged by how useful it is.

See it happen

An article says “new study: journaling doubles productivity”.

The ordinary first approach

Doubling is huge — she should start journaling today.

With the idea

She checks: 40 students, one week, self-rated productivity, no comparison group. She treats it as an idea to test.

What changed

She sized the claim to its evidence.

Easy to get wrong

• Treating one study as settled.
• Confusing “linked with” and “causes”.
• Ignoring who was studied and for how long.

Try it now: Four questions for any study

1. What kind of study was it?
2. How big was the effect, and in whom?
3. What was measured, and for how long? Then: how would I test this on myself?

Apply it to one of your habits

For one technique you use in your habits, what kind of evidence supports it?

Reflect

• Which of the four questions do you usually skip?

Go deeper — evidence & sources

• Harkin, Webb, Chang, Prestwich, Conner, Kellar, Benn & Sheeran (2016). Does monitoring goal progress promote goal attainment? A meta-analysis of the experimental evidence. Psychological Bulletin. doi:10.1037/bul0000025
• Michie, Richardson, Johnston, Abraham, Francis, Hardeman and colleagues (2013). The Behavior Change Technique Taxonomy (v1) of 93 Hierarchically Clustered Techniques. Annals of Behavioral Medicine. doi:10.1007/s12160-013-9486-6