Fast Facts

Gary Pattillo is reference librarian at the University of North Carolina-Chapel Hill, e-mail:

Reference rot in electronic theses and dissertations

In a study of one electronic theses and dissertations repository, authors found that documents deposited from 2011 to 2015 exhibited 23 percent link rot. That is, the reference links send users to webpages that are no longer available. Of the 77 percent of references that were still active, about half of those exhibited content drift, where web pages remain available but the contents have changed.

Mia Massicotte and Kathleen Botter, “Reference rot in the repository: A case study of electronic theses and dissertations (ETDs) in an academic library,” Information Technology and Libraries (Online), 36(1), 11-28, (retrieved September 14, 2017).


The total number of business and consumer emails sent and received per day is expected to reach 269 billion in 2017, according to one report. This number is likely to continue to grow at an average annual rate of 4.4 percent over the next four years, reaching 319.6 billion messages per day by the end of 2021. In 2017, the number of worldwide email users will top 3.7 billion.

The Radicati Group, Inc., “Email Statistics Report, 2017-2021,” 2017, (retrieved September 14, 2017).

Postsecondary libraries

In 2015 (the latest reliable data available), eligible Title IV degree-granting institutions reported approximately 1.3 billion items in physical library collections (books and media) and about 839 million items in electronic library collections (digital/electronic books, databases, and digital electronic media). The same institutions employed approximately 43,000 full- and part-time librarians, curators, and archivists.

Scott A. Ginder, Janice E. Kelly-Reid, and Farah B. Mann, “Enrollment and Employees in Postsecondary Institutions, Fall 2015; and Financial Statistics and Academic Libraries, Fiscal Year 2015: First Look (Provisional Data),” (NCES 2017-024), February 2017, U.S. Department of Education, Washington, D.C.: National Center for Education Statistics, (retrieved September 10, 2017).

Preprint sites

“Six new preprint sites were rolled out on 29 August. The services, which host research papers before formal publication, include paleorXiv for paleontology and INA-rXiv, a preprint server for Indonesian research. The other sites cover research on nutrition, library sciences, sports and exercise, and mind and contemplative practices. The servers are supported by software developed by the Center for Open Science in Charlottesville, Virginia, which already hosts eight other preprint services.”

“Alan Turing’s notes, runaway salmon and illegal gold-mining: Nature News & Comment,” Nature, 548, 504-505, August 30, 2017, doi:10.1038/548504a (retrieved September 10, 2017).

Mobile apps

Digital media usage time is driven by mobile apps, with smartphone apps accounting for half of all time spent. The average user spends 2.3 hours per day using mobile apps. Seventy-seven percent of app users use a news app, with Apple News representing the #1 ranked app by unique visitors.

Andrew Lipsman and Adam Lella, “The 2017 U.S. mobile app report,” comScore, August 24, 2017, (retrieved September 14, 2017).

Copyright American Library Association

Article Views (Last 12 Months)

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Contact ACRL for article usage statistics from 2010-April 2017.

Article Views (By Year/Month)

January: 3
February: 2
March: 4
April: 5
May: 2
June: 2
January: 2
February: 2
March: 3
April: 1
May: 5
June: 0
July: 4
August: 4
September: 38
October: 501
November: 4
December: 2
January: 2
February: 2
March: 3
April: 5
May: 7
June: 17
July: 5
August: 7
September: 11
October: 3
November: 11
December: 4
January: 9
February: 10
March: 15
April: 55
May: 81
June: 55
July: 2
August: 0
September: 2
October: 3
November: 3
December: 0
April: 0
May: 0
June: 0
July: 0
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October: 126
November: 16
December: 7