Draft:China Academic Digital Associative Library

China Academic Digital Associative Library

大学数字图书馆国际合作计划
Abbreviation	CADAL
Formation	2000 (2000) (MOU signed December 2000)
Type	Digital library consortium
Purpose	Mass digitization of academic works
Headquarters	Zhejiang University, Hangzhou, China
Members	120+ academic libraries (2020); 939 in China plus 40 overseas (2023)
Lead institutions	Zhejiang University; Chinese Academy of Sciences
Affiliations	Ministry of Education (China); Carnegie Mellon University; Million Book Project
Website	cadal.edu.cn

The China Academic Digital Associative Library (CADAL; Chinese: 大学数字图书馆国际合作计划; pinyin: Dàxué Shùzì Túshūguǎn Guójì Hézuò Jìhuà) is a government-sponsored digital library consortium in China dedicated to the mass digitization of books and other academic materials. Led by Zhejiang University and the Chinese Academy of Sciences, it is a cooperative project of more than 120 academic libraries—about half of them in China—that produces and shares a large collection of scanned works for the use of patrons at participating institutions. It began in 2000 as the Chinese arm of the international Million Book Project, and by the 2020s its holdings were reported to exceed 2.8 million items.

Because much of its collection consists of in-copyright works, access is tiered according to copyright status: public-domain and ancient materials are more openly available, while access to in-copyright works is restricted to registered users at participating libraries, who borrow portions of a book that must be returned before the material becomes available to other users.

History

CADAL originated in the China–US Million Book Digital Library Project, the Chinese component of the wider Million Book Project initiated in 2000 by Raj Reddy, a professor at Carnegie Mellon University. The broader initiative was a collaboration among universities and institutes in China, the United States, and India, funded by the Chinese Ministry of Education (MOE), the U.S. National Science Foundation (NSF), and the Indian government; Carnegie Mellon University and Zhejiang University pioneered the technical work. A memorandum of understanding on the China–US project was signed in December 2000, and the Chinese effort took the short name CADAL, originally standing for China–America Digital Academic Library.

In 2002 the Ministry of Education committed RMB 70 million to a first phase aimed at scanning one million books. The project was led by Zhejiang University and the Chinese Academy of Sciences as principal investigators and jointly implemented by fourteen other leading universities, among them Peking, Tsinghua, Fudan, and Nanjing. The one-million-book target was reached by August 2006, completing the first phase, and a second phase was planned for 2008–2011 to digitize a further million works along with audio, video, newspapers, and other materials. The second phase was formally launched on 1 April 2010 at Zhejiang University under the leadership of Pan Yunhe, reorienting the project from purely expanding its holdings toward cross-media services; it was carried out as part of the Ministry of Education's "211" program.

The project was subsequently renamed the China Academic Digital Associative Library and grew into a standing consortium centered on Zhejiang University; from the mid-2010s a select group of overseas libraries also gained access. By 2023 it drew on the efforts of 939 academic libraries in China together with 40 more in Asia, North America, and Europe, and had established a "Digital Knowledge Service Alliance" in 2021.

Collection

CADAL's principal output is scanned books, both in and out of copyright, alongside dissertations, periodicals, newspapers, and multimedia materials. Content is drawn from the collections of the partner institutions: pre-1911 works that are out of copyright, books and journals published from 1911 onward, and dissertations of the partner institutions, with English-language selection carried out largely in the United States and focused on public-domain works and titles for which digitization permission had been obtained.

A description of the collection lists roughly 800,000 books published after 1949, 690,000 works in Western languages, 240,000 ancient texts (including the Xuxiu Siku Quanshu), 180,000 Republican-era (Min Guo, 1911–1949) works and 155,000 Republican-era periodical issues, 40,000 newspaper issues, and smaller special collections such as Manchuria Railway titles, local gazetteers, and overseas-remittance documents, along with audio, video, and images. By the completion of its first two phases the total was reported at more than 2.8 million items; an earlier 2008 snapshot had recorded about 1.41 million scanned items.

Technology

Books were scanned at an archival resolution of 600 dpi, high enough to permit printing as legible as the original pages. Sixteen Chinese partner institutions operated their own scanning centers, while English books shipped from the United States and Hong Kong were digitized at a center established in the Shenzhen free-trade zone.

For each book the system stored both a page-image file and a text file produced by optical character recognition (OCR)—the images used for viewing and the OCR text for searching. A dedicated OCR center equipped with 130 servers could recognize more than 4,000 books (about one million pages) per day. To speed image delivery, CADAL adopted the DjVu format, an imaging technology developed at AT&T Labs that decodes only the on-screen region of a page in real time, yielding files far smaller than comparable TIFF, JPEG, or PDF images. By 2008 the database held roughly 300 million pages, at about 50–60 megabytes per book. For metadata, CADAL released an "Edocument Metadata" standard combining Dublin Core with CNMARC and developed software called "MetaCreator" at Zhejiang University Libraries; for English books, OCLC supplied MARC records at no charge.

Access and use

A portal hosted at Zhejiang University Libraries lets users at participating institutions search and view the project's public-domain digitized collections freely from within the member institutions' IP ranges; scanned page images are used for viewing while OCR-generated text supports searching. By 2008 the collection was being accessed from 71 nations and regions, with an average of 3,681 books (149,672 pages) read per day over the preceding year.

In 2015 CADAL—described at the time as a consortium of more than 70 Chinese university libraries—partnered with the Internet Archive to digitize 500,000 English-language academic books, with teams operating in the United States, Shenzhen, and at Zhejiang University in Hangzhou.

Significance

CADAL is one of China's major state-backed academic digitization programs and, together with platforms such as the China Academic Library and Information System (CALIS), forms part of the country's effort to build comprehensive digital access to its published record. Its collaboration with Carnegie Mellon under the Million Book Project made it an early and unusually large example of cross-border mass digitization.

See also

• Million Book Project
• China Academic Library and Information System
• SuperStar Digital Library
• China National Knowledge Infrastructure
• Wanfang Data
• Zhejiang University Library
• Digital library