Evidence-appraisal glossary
Imputation
Imputation is the practice of filling in missing values with estimated ones so that participants with incomplete records can still be included in an analysis.
Also called: multiple imputation, data imputation.
Methods range from simple substitution to multiple imputation, which generates several plausible values and pools the results to reflect the added uncertainty. Done well, imputation reduces the bias that comes from dropping incomplete cases; done crudely, it can invent stability that the data do not support. A trustworthy report says which method was used and often tests whether the conclusions hold under different assumptions.
This is a plain-language methodology definition for reading research. It is general education, not medical advice.