## Citation analysis and Hirsch index for SUM employees

**The Hirsch index (H-index)** is a measure of the importance and relevance of all the scientific work of a given author, an indicator that characterises their entire scientific achievements and not only one or a few cited publications.

The value of the index is influenced by two factors: the cited publications (regardless of the publication date of the paper) and the number of citations. The index is "h" if "h" of an author's publications have been cited at least "h" times.

A scientist with a high Hirsch index is an 'established author' in his or her field. Please note that the total number of citations for all publications by a given author does not affect the value of the Hirsch Index.

The Bibliography and Bibliometrics Department** calculates the H-index separately for the Web of Science and the Scopus database**. This practice is dictated by the fact that the two databases contain different resources. The following examples illustrate these differences.

Example 1

The author has 5 publications, each cited at least once. To determine the Hirsch index, we rank all of the author's publications in descending order by number of citations. In our example, the arrangement of papers is as follows:

1. first paper - 10 citations

2. second paper - 9**3.** 3. third - **4**

4. fourth - 3

5. fifth - 1**Order number of publications must be less than or equal to the number of citations** - the highest number possible. In the example given, this is the number 3 (H-index = 3).
The fourth publication already has an order number higher than the number of citations (3), so the Hirsch index in this case cannot be 4.

Take a note! If the fourth publication gains at least one citation (it will therefore have 4 citations), then the author's H-index will be 4.

The Hirsch index is a dynamic measure (its value can change from day to day), so it must be based on the most recent data.

Example 2

The author has 5 publications. To determine the Hirsch index, we rank all of the author's publications in descending order by number of citations. In our example, the arrangement of papers is as follows:

1. first paper - 160 citations**2.** second - 100

3. third - 1

4. fourth - 0

5. fifth - 0

Order number of publications must be less than or equal to the number of citations. In the example given, H-index = 2.

Exemple 3

The author has 5 publications. To determine the Hirsch index, we rank all of the author's publications in descending order by number of citations.

In our example, the arrangement of papers is as follows:

1. first paper - 9 citations

2. second - 8

3. third - 7

4. fourth - 6**5. **fifth - 5

The order number of publications must be less than or equal to the number of citations. In the example given, H-index = 5.

How to calculate the H-index in the Web of Science database?

**Tutorial PDF version**

The material is available under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 International (CC BY-NC-ND 4.0)* licence

How to calculate the H-index in the Scopus database?

**Tutorial PDF version**

The material is available under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 International (CC BY-NC-ND 4.0)* licence

**Citation analyses** are based on the author's achievements, which are recorded in the SUM Publications Database. Long-standing employees of the University are requested to ensure that all their publications are included in the database. If there are any gaps, please send in publications produced during your employment at SUM. For recently recruited staff, please note that citation analyses can only be carried out after a list of publications (outside the period of employment at SUM) has been submitted.

Analyses are based on data in the global databases **Web o Science** and/or **Scopus**. It is also possible to prepare a citation analysis based on these databases yourself.

Extended information on the Hirsch Index can be found on the blog of Emmanuel Kulczycki (Associate Professor at Adam Mickiewicz University in Poznan).

The Bibliography and Bibliometrics Department focuses on activities that increase the visibility of our authors' citations by:

- grouping publications by SUM staff in structured profiles (It is possible that the algorithms of the databases may group the publications of an author in several separate profiles or mix them with the publications of other authors with the same last name and the same first name or initial);
- reporting of missing citations of publications
- correcting misspellings of authors' names;
- monitoring that new publications are not placed in the wrong or new profile.

These measures ensure that our authors' citations do not get "lost" and that the Hirsch index of individual authors is not accidentally lowered.

If you need a citation analysis of your work (or have questions related to this issue), please contact the Bibliography and Bibliometrics Department:

+48 **32 208 36 17 **or** 32 208 36 22**, e-mail: bibinfo@sum.edu.pl.