Recall Bias

Error caused by inaccurate or incomplete recollection of events. A particular concern for retrospective survey questions.

Read First

• Lower salience and longer recall periods increase forgetfulness [1]
• How long is "too long" for a recall period for a survey question? It depends on the type of event: infrequent events (e.g. purchases of major assets) will be memorable for longer periods of time than routine events (e.g. use of public transportation).

Guidelines

How to avoid?

Useful strategies:

1. Where possible, use methods to reduce recall periods for key indicators. For example, more frequent follow-up surveys by phone, or personal diaries
2. When Piloting your Survey, carefully test different recall periods; if possible try shorter and longer periods and check for differences in variance

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This article is part of the topic Questionnaire Design

Additional Resources

• Development Impact Blogpost on Response Error in Consumption Surveys and the related paper
• Blog from Financial Access on The Reliability of Self-reported Data
• Jishnu Das, Jeffrey Hammer, Carolina Sánchez-Paramo, The impact of recall periods on reported morbidity and health seeking behavior, In Journal of Development Economics, Volume 98, Issue 1, 2012, Pages 76-88, ISSN 0304-3878, https://doi.org/10.1016/j.jdeveco.2011.07.001.

(http://www.sciencedirect.com/science/article/pii/S0304387811000708) Keywords: Health; Recall effects; Health seeking behavior; Impacts of sickness