Meta-Research: Reader engagement with medical content on Wikipedia

  1. Lauren A Maggio  Is a corresponding author
  2. Ryan M Steinberg
  3. Tiziano Piccardi
  4. John M Willinsky
  1. Department of Medicine, Uniformed Services University of the Health Sciences, United States
  2. Lane Medical Library, Stanford University School of Medicine, United States
  3. École Polytechnique Fédérale de Lausanne, Switzerland
  4. Graduate School of Education, Stanford University, United States
3 figures, 6 tables and 1 additional file


Page length of WikiProject Medicine (WPM) and other Wikipedia (W) pages.

Distribution of page lengths in characters for WikiProject Medicine (WPM) pages and the rest of Wikipedia (W) on April 20th, 2019. The difference between the two distributions is statistically significant according to Mann–Whitney U test (p<0.001, two-tailed).

Open access reference displayed in Wikipedia.

A research study cited on Wikipedia’s “diabetes” page displayed on desktop device with “freely accessible” icon for PubMed Central (PMC) link and on a mobile device without the open access icon. There is an “up click”( ^ ) in front of the citation on the desktop device, which returns reader back to footnote 46 in the text.

Example of information displayed when hovering over footnotes in Wikipedia.

(A) An external link on the Hepatitis page, revealed by “hovering” over the footnote number, indicating that the source is a systematic review conducted by the Cochrane Collaboration (with a green icon PMC link signaling open access to the source). (B) Hovering over a different footnote number on the same page reveals a different external link for the 19th and relatively recent edition of a medical textbook from a leading publisher.


Table 1
Types of engagement with external links

Different events captured by the CitationUsage Schema that reflect how readers of Wikipedia pages engage with external links.

Engagement typeGeneral description
External clickA click on a link located on a Wikipedia page leading to a web page outside of Wikipedia.
HoverAn event that occurs when a reader hovers over a link for at least 1000 milliseconds on a Wikipedia page.
Footnote clickA click of an internal footnote link – [1] – that takes the reader to the reference section at the bottom of the Wikipedia page.
Up clickA click of an arrow – ^ – that takes the reader from the reference at the bottom of the Wikipedia page back to the citation in the main text.
Table 2
Factors that distinguish WPM pages from the rest of Wikipedia.

Differences between WPM pages and pages in the rest of Wikipedia (W) based on data collected on April 20th, 2019.

Wikipedia pages34,3245,839,083
Pages with external links32,6095,210,746
External links945,64560,851,396
Links per page (with links)29.011.7
Page length (characters)13,084.97,676.4
Characters per link (pages with links)450.3657.3
Table 3
Comparing pageviews between WikiProject Medicine (WPM) and other Wikipedia (W) pages.

The average number of pageviews WikiProject Medicine (WPM) and the rest of Wikipedia (W) received per day for different types of devices between March 22nd and April 22nd, 2019.

WPM (%)W (%)
Pageviews on desktop device1,957,821.6 (33.3)97,956,273.1 (42.9)
Pageviews on mobile device3,917,648.8 (66.7)130,488,855.3 (57.1)
Total number of pageviews5,875,470.4 (100)228,445,128.4 (100)
Table 4
Frequency of different types of link engagement per day.

The average number of times per day that readers of WPM and W pages engaged with external links using one of the event types captured from March 22nd to April 22nd, 2019.

Event typeWPMW
 Total (%)Desktop (%)Mobile (%)Total (%)Desktop (%)Mobile (%)
Hover over link48,748.9 (46.9)45,814.8 (60.3)2,934.1 (10.5)1,122,704.0 (32.7)1,057,982.0 (47.2)64,722.0 (5.4)
Footnote click27,739.4 (26.7)10,948.8 (14.4)16,790.6 (60.3)722,131.0 (21.0)235,245.0 (10.5)486,886.7 (40.7)
External click25,811.9 (24.9)17,792.3 (23.4)8,019.7 (28.8)1,557,125.0 (45.3)915,445.1 (40.9)641,676.4 (53.6)
Up click1,539.5 (1.5)1,422.8 (1.9)116.4 (0.4)34,738.0 (1.0)31,230.1 (1.4)3,508.1 (0.3)
All events103,839.7 (100)75,978.7 (100)27,860.8 (100)3,436,698.0 (100)2,239,902.2 (100)1,196,793.2 (100)
Table 5
Number of pageviews per engagement event.

The frequency of each event per day was divided by the average number of daily pageviews for WPM and W pages from March 22nd to April 22nd, 2019. The lower the number of pageviews per event the greater the event frequency. Difference between each pair of WPM and W distributions is statistically significant as derived from Fisher’s exact test (p<0.001, two-tailed).

Hover over link120.542.71,335.2203.592.62,016.1
Footnote click211.8178.8233.3316.3416.4268.0
External click227.6110.0488.5146.7107.0203.4
Up click3,816.61,376.133,655.06,576.23,136.637,196.5
All events56.625.8140.666.543.7109.0
Table 6
Summary of data collected.

Summary statistics selected from the tables above, comparing WikiProject Medicine (WPM) pages and readers to the rest of Wikipedia (W) pages and readers. (a) The “4.4 more pageviews” reflects the ratio of WPM to W pages (0.6%) compared to the ratio of WPM to W pageviews/day (2.6%). (b)“WPM readers” and “W readers” refer to the behaviors of those reading a WPM and/or W page during the data collection period.

WPM pagesW pagesWPM pages, compared to other W pages,...
Page length (characters)13,0857676…are 70.5% longer by character count.
Characters/external link (on pages with links)450.3657.3…possess a 31.5% greater external link density.
Pageviews/day5,875,470.40228,445,128.40…receive 4.4 more pageviews per day.a
WPM readersW readersWPM readers, compared to rest of W readers,...b
Time before engagement (sec)47.532.8…take 44.8% longer before engaging in a link activity.
Pageviews/link engagement56.6066.47…engage 17.5% more often with links per pageview.
Pageviews/hover120.5203.5…hover over links 68.9% more often per pageview.
Pageviews/footnote click211.8316.3…click footnote numbers 49.3% more often per pageview.
Pageviews/external click227.6146.7…click external links 35.5% less often per pageview.

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  1. Lauren A Maggio
  2. Ryan M Steinberg
  3. Tiziano Piccardi
  4. John M Willinsky
Meta-Research: Reader engagement with medical content on Wikipedia
eLife 9:e52426.