ISI Essential Science Indicators provides internet access to a unique and comprehensive compilation of essential science performance statistics and science trends data derived from ISI's data sets.

The chief indicators of output, or productivity, are journal article publication counts. For influence and impact measures, ISI Essential Science Indicators employs both total citation counts and cites per paper scores. The former reveals gross influence while the latter shows weighted influence, also called impact.

ISI Essential Science Indicators is divided into four main sections:

Citation Rankings: Using total citation counts and cites per paper scores, the ISI Essential Science Indicators determines the rankings of:

• the most-cited authors
• the most-cited institutions (universities, corporations, government research labs)
• the most-cited countries
• the most-cited journals

Most Cited Papers: In addition to providing rankings for authors, institutions, countries, and journals, ISI Essential Science Indicators contains the most highly cited papers and hot papers. Papers are selected for ISI Essential Science Indicators based on percentile rankings specific to fields of science and specific time periods. While highly cited papers are chosen from the most recent 10 years of data, hot papers focus on very recent papers (from the past two years) that show an unusual rate of citation in the current period.

Citation Analysis: ISI Essential Science Indicators contains Baselines information used to formulate the thresholds used in the selection process. Another unique feature is the listing of research areas called Research Fronts, algorithmically derived topics reflecting research intensive and breakthrough areas of current science.

Commentary: Brief editorial discussions that provide guidance on data analysis and interpretation enhance the tables, charts, and other data sets presented in ISI Essential Science Indicators. An editorial feature called Special Topics focuses on selected areas of research.