Number and percentage of publication in the top 1% and 10% based on citations by category, year, and document type.
Documents in Top 1%
Definition
Percentage of publications in the top 1% based on citations by category, year, and document type.
When to Use It
Research excellence: % Documents in Top 1% is an indicator of research excellence, as only the most highly cited papers would make the top 1% in their respective field, year, and document type.
Large datasets: % 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.
Limitations and Precautions
Small datasets: Although the top 1% 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. This, along with the % Documents in Top 10% indicator, should be used with a great deal of caution when looking at small datasets such as the output of an individual researcher.
Top 10%: % Documents in Top 1% can be used in conjunction with other indicators to provide a more complete picture of performance. It is complemented very well by the % Documents in Top 10% indicator, giving a broader picture of high performance (10%) and excellence (1%). The % Documents in Top 10% is also more appropriate than the % Documents in Top 1% when the size of the dataset is smaller, but is still more appropriate for large to medium size datasets.
How It's Calculated
Top 1% most cited documents (as defined in the description of the Average Percentile indicator) in a given subject category, year, and publication type ÷ total number of documents in a given set of documents = % Documents in Top 1%
How to Interpret It
A higher value is considered to be higher performance. A value of “1” for a set of documents represents that 1% of the publications in that set are in the top 1% 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 1% of the world and a value of less than “1” would represent that less than 1% of the papers in the set are in the top 1% of the world.
Complementary Indicators
- % Documents in Top 10%
- Category Normalized Citation Impact
- Journal Normalized Citation Impact
- Average Percentile
Publications in Top 10%
The % Documents in Top 10% indicator 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.
The following is a sample citation distribution. InCites also includes pre-calculated indicators of collaboration which can be used for complementary performance indicators.