Question-behaviour effect

Asking people about their intentions or satisfaction can change what they later do.

Motivation and commitment Mainly on Post-purchase pages
Where it applies

Two of the eight page areas.

HomepageNot typical CategoryNot typical SearchNot typical ProductNot typical CartNot typical CheckoutNot typical Post-purchaseMainly here

It also applies sitewide, on every page. See everything at work on Post-purchase pages

How to use it

Three ways to use it, and two to avoid.

  • Send a short post-purchase satisfaction survey.
  • Ask “will you reorder?” in a short post-purchase survey.
  • Treat any uplift in later purchasing as a possible small bonus, not the reason to survey.
  • Avoid: disguising selling as research.
  • Avoid: promotional content in a survey email, which likely makes it count as direct marketing.
What the research found

Probably real, but very small, and smaller still in the better-designed studies.

The meta-analytic effect is g = 0.14, falling to about 0.07 in the better-designed studies.

Morwitz and colleagues found people asked about buying a car or computer later bought more, and Dholakia and Morwitz found surveyed financial-services customers bought more and defected less. But a meta-analysis of 66 studies found a very small effect (g = 0.14), about 0.07 in the better-designed studies, with signs of publication bias.

Key research

Four sources, each checked.

Last reviewed

Morwitz, Johnson & Schmittlein (1993) Does Measuring Intent Change Behavior? J. Consumer Research Read the source Dholakia & Morwitz (2002) The Scope and Persistence of Mere-Measurement Effects: Evidence from a Field Study of Customer Satisfaction Measurement J. Consumer Research Read the source Wilding, Conner, Sandberg, Prestwich, Lawton, Wood, Miles, Godin & Sheeran (2016)Meta-analysis The question-behaviour effect: A theoretical and methodological review and meta-analysis European Review of Social Psychology Read the source Chandon, Morwitz & Reinartz (2005) Do Intentions Really Predict Behavior? Self-Generated Validity Effects in Survey Research J. Marketing Read the source
Before you use it · UK law

Do not disguise selling as research. A survey email with promotional content likely counts as direct marketing.

This is simply a pointer to check, not legal advice. Seek legal advice before you put this principle into action.