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fnielsen is (me!) Finn Årup Nielsen, Lyngby, Denmark, - an engineer working with data science. I edit in Wikipedia, perform research on wikis and Wikipedia.

My work[edit]

Skallerupvognen. From Nationalmuseet. Taken as part of the collaborative project "Wikipedia Loves Nationalmuseet".
Example photo. Kongens Lyngby.
Example photo. A local newspaper has used this photo [2].

On Wikipedia and sister projects[edit]

I have been active on the English and Danish versions of Wikipedia, with the first English Wikipedia entry August 23 2002 and the first Danish February 11 2002.

Among the articles I have added to are non-negative matrix factorization, ratio distribution, intraclass correlation, Niels A. Lassen, John Lykoudis and 5-HTTLPR. My English edits have usually been related to my work. On the Danish Wikipedia I usually write articles that are not related to my work. I also take photos for Wikimedia Commons. Most photos have been of Copenhagen and suburbs.

(I have a sandbox as a subpage where I try to understand Wikipedia tables, templates, substitutions, transclusions and other technical details of Wikipedia.)


I am a member of Wikimedia Denmark, and presently is a member of the board. I have been at Wikimania in Alexandria, Gdansk and London.


I have made a tool that converts a PubMed/MEDLINE identifier, PMID, to a cite journal template. As of 2008 it is available from [3]

On the Toolserver I had a online visualization service called revvis. Enabled for the Danish Wikipedia, it shows the sequential collaboration network for a Wikipedia article.

The most recent Toolforge tools are Scholia, Wembedder, CVRminer and Ordia.

Research on Wikipedia[edit]

Article-by-author matrix factorization[edit]

I participated in WikiSym 2006 in Odense and had a short talk in the workshop about Wikipedia research organized by Jakob Voß and Angela Beesley. The slides used for the presentation are available from the department archive[1]: Non-negative matrix factorization decomposed a article-by-author data matrix for identification of clusters of authors and articles.

Scientific citations in Wikipedia[edit]

In 2007 I looked at the outbound citations from Wikipedia (using Template:Cite journal) to scientific journals.[2] Nature and Science were the most cited. I compared the number of citations with citation information from Journal Citation Reports of Thomson Scientific, and the correlation between the two sets of values was not bad, e.g., when a scientific journal had many citations it tended to also have many Wikipedia citations. An updated scatter plot for the July 2007 database dump is available [4].

I also tried to cluster scientific journals and Wikipedia articles and made a longitudinal comparison of the citation information. This is described in Clustering of scientific citations in Wikipedia.

The data set used for the clustering is available from the homepage [5] and a couple of researcher have used it to test machine learning algorithms, see the references on Google Scholar.

Wiki for representing and computing with scientific data[edit]

I am experimenting with representing scientific data in a wiki-like environment. My first attempt was a spreadsheet link online service for personality genetics. It is available from:

I now mostly work with the "Brede Wiki".

This MediaWiki-based wiki can represent spreadsheet-like data and meta-analysis is presently performed with an online script.

On Wikimania 2010 I tried to argue for a way to represent scientific data in Wikipedia: Wikipedia is not the sum of all human knowledge. I look forward to see how Wikidata can be used for such data.

Review of Wikipedia research[edit]

Since 2008 I have been writing a review on Wiki and Wikipedia research entitled Wikipedia research and tools: Review and comments. I now collaborate with fellow researchers (Chitu Okoli and others) on the Internet to summarize and review Wikipedia research. We presently have a long working paper entitled The people's encyclopedia under the gaze of the sages: a systematic review of scholarly research on Wikipedia, see at . We maintain the data for the review on a Semantic MediaWiki at The setup of this wiki was inspired by WikiPapers ( at and my Brede Wiki.

I have also written a popular science overview of Wikipedia research in Danish: Wikipedia - nørdernes sejr over vandalerne?.


I maintain blogs where I sometimes write posts relating to Wikipedia. These may be opinionated or related to my work. I was originally writing from Posterous, but as this is closed down Wikipedia posts from my blogs can be found here: (nothing here yet)

Examples of blog posts are:


Conflict of Interest Statement[edit]

I am working or have been employed by:

I have received grants from:

I received gifts associated with:

See also[edit]

List of publications[edit]


  1. ^ Finn Årup Nielsen, Wiki(pedia) and neuroinformatics, 2006 August 23. [1]
  2. ^ Finn Årup Nielsen (2007). "Scientific citations in Wikipedia". First Monday. 12 (8). {{cite journal}}: Unknown parameter |month= ignored (help)