% Documents in Top 1% and % Documents in Top 10%

The % Documents in Top 1% indicator is the top one percent most cited documents (as defined in the description of Average Percentile) in a given subject category, year and publication type divided by the total number of documents in a given set of documents, displayed as a percentage. A higher value is considered to be higher performance. A value of “1” for a set of documents represents that one percent of the publications in that set are in the top one percent of the world regardless of subject, year and document type and would therefore be considered to be performing at the same level as world average. A value above “1” represents that more than one percent of papers in the set are in the top one percent of the world and a value of less than “1” would represent that less than one percent of the papers in the set are in the top one percent of the world.

The % Documents in Top 1% indicator is considered to be an indicator of research excellence as only the most highly cited papers would make the top one percent in their respective field, year and document type. The indicator can be used in conjunction with other indicators to provide a more complete picture of performance. The % Documents in Top 1% indicator can be applied to any level of aggregation (author, institution, national/international, field).

Although the top one percent is a relevant measure of excellence, by its nature it is typically only a small percentage of any document set and therefore the statistical relevance of small sample sizes is a significant concern.

The % Documents in Top 1% is best used with large datasets such as the accumulated publications of an institution, country or region and for a publication window of several years. The % Documents in Top 10% is very similar to the % Documents in Top 1% simply with a threshold of 10 percent instead of one percent. Therefore, typical performance will be around a value of 10 and values of higher than 10 would be considered above average performance. The two indicators complement each other very well to give a broader picture of highly performing research (10 percent) and excellence (one percent).

The % Documents in Top 10% is also more appropriate than the % Documents in Top 1% when the size of the data set is smaller. However, it is still only appropriate for large to medium size data sets and should be used with a great deal of caution when looking at small datasets such as the output of an individual author.

Complementary indicators include:

• Normalized Citation Impact
• Journal Normalized Citation Impact
• Average Percentile

Sample Citation Distribution

However InCites also includes pre-calculated indicators of collaboration which can be used for complementary performance indicators. The section below describes those indicators.