This is an archived version. For the current version, please go to training.cochrane.org/handbook/current.

Table 10.1.a: Definitions of some types of reporting biases

Type of reporting bias

Definition

Publication bias

The publication or non-publication of research findings, depending on the nature and direction of the results

Time lag bias

The rapid or delayed publication of research findings, depending on the nature and direction of the results

Multiple (duplicate) publication bias

The multiple or singular publication of research findings, depending on the nature and direction of the results

Location bias

The publication of research findings in journals with different ease of access or levels of indexing in standard databases, depending on the nature and direction of results.

Citation bias

The citation or non-citation of research findings, depending on the nature and direction of the results

Language bias

The publication of research findings in a particular language, depending on the nature and direction of the results

Outcome reporting bias

The selective reporting of some outcomes but not others, depending on the nature and direction of the results