Outputs in top percentiles indicate the extent to which an entity’s outputs are present in the most-cited thresholds of a data source per publication year. 10% is recommended as the default threshold. Other thresholds are the number of publications within the top 1%, 5% and 25% of most-cited publications. An entity can be an institution, a research group or an individual researcher.
Outputs in top percentiles can be presented as an absolute count or a percentage of outputs. The percentage option should be used when comparing entities of different sizes, to field-normalise this variable.
Field normalisation is important for cross-disciplinary benchmarking, e.g. citation counts tend to be higher in disciplines such as immunology and microbiology, whose academics tend to publish frequently and include long reference lists. This is in contrast to mathematics, where publishing 1 item every 5 years that refers to 1 or 2 other publications is common. These differences reflect the distinct behaviour of researchers in distinct subject fields and not differences in performance.
Outputs in top percentiles metric is useful for:
Note that the time period does not refer to the year in which citations were received, but to the year in which outputs were produced.
Outputs in top percentiles will vary for the same research entity in different database sources. Comparisons should, therefore, only be made from a single source. See appropriate use of publication and citation metrics.