1) A quality of a point estimate obtained from a set of observations having a small variance.

Note: A narrow confidence interval around a point estimate indicates a more precise estimate of effect than a wide confidence interval. Note that a precise estimate is not necessarily accurate.

2) A measure of the likelihood of random errors in the results of a study, meta-analysis or measurement.

Note: In a meta-analysis, the weight given to the results of each study in the overall estimate of the effect of an intervention is often based on the precision of each study, which is estimated using the inverse of the variance of the estimate of effect or the sample size.

3) In a literature search, the number of relevant citations, divided by the total number of citations retrieved, i.e. the proportion of studies meeting the inclusion criteria for a clinical trials register or a literature review.

(Related concept: accuracy)