In epidemiology, reporting bias is defined as “selective revealing or suppression of information” by subjects (for example about past medical history, smoking, sexual experiences).
By extension, in empirical research in general, the term reporting bias may be used to refer to a tendency to under-report unexpected or undesirable experimental results, attributing the results to sampling or measurement error, while being more trusting of expected or desirable results, though these may be subject to the same sources of error. In this context, reporting bias can eventually lead to a status quo where multiple investigators discover and discard the same results, and later experimenters justify their own reporting bias by observing that previous experimenters reported different results. Thus, each incident of reporting bias can make future incidents more likely. Sociologist Christopher B. Doob refers to this practice as selective reporting in explaining the Power of the Press and defines it as biased coverage of news issues that promotes corporate interests and downplays, denigrates, or ignores issues and groups challenging these issues.
Types of reporting bias
- Publication bias: The publication or nonpublication 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.