Presentation on theme: "The Secrets of Full-text Databases: The Overlap Between a Same Vendor's Subject Database and General Database, and the Differences between Different Vendors."— Presentation transcript:
The Secrets of Full-text Databases: The Overlap Between a Same Vendor's Subject Database and General Database, and the Differences between Different Vendors in Embargo Xiaotian Chen Bradley University Library, Peoria, IL Presentation at Brick and Click Libraries Maryville, MO. 10/18/2002
Data comparisons show that full-text titles in a subject database are considerably (sometimes nearly 100%) overlapped with those on the general database of the same vendors, and that there are huge differences between vendors in handling full-text embargo. Librarians should be well aware of these "secrets" to make informed decisions in both licensing databases and helping users.
Databases of 3 vendors were analyzed for the overlap issue: EBSCO, Gale, and H.W. Wilson. Wilson has highest overlap percentage: nearly 100%; Gale and EBSCO have the average around 50%, ranging from about 25% to about 80%, depending on databases.
Wilson’s subject databases and general databases (through FirstSearch): almost 100% overlap, as of 7/02. When compared with Wilson Select Plus or Omnifile Full Text:
Applied Science and Technology Full Text : Only 3 out of the 135 (2.2%) full-text titles are unique. The 3 titles are: Applied Microwave & Wireless ( ), Food Engineering ( X), Journal of Coastal Research ( )
Wilson Art Full Text: Only 5 out of 114 (or 4.3%) full-text titles are unique: Art & Antiques ( ), Arte Veneta ( ), Bulletin of the American Schools of Oriental Research ( X), Visible Language ( ), Werk, Bauen + Wohnen ( ).
The same is true with other Wilson subject databases, such as: Wilson Business Full Text; Education Full Text; General Science Full Text; Humanities Full Text; Social Science Full Text; etc.
Gale Health and Wellness Information compared with Expanded Academic ASAP (as of 7/02): HWI has 246 unique titles out of 516 (or 47.7% unique). But those unique titles are mostly health newsletters that may not fit the theme of Expanded Academic ASAP, while key journals and magazines tend to be overlapped, e.g, JAMA is on both.
EBSCO When compared with Academic Search Elite (as of 8/02), Health Source: Nursing/Academic Ed has 120 unique titles out of 576 (or 20.8%). Business Source has 845 unique titles out of 1092 (or 77.4%). Business unique titles include key business journals such as Harvard Business Review.
Overlap conclusion Licensing one big general FT, such as Wilson Select Plus, should be more cost effective than paying for multi subject FT databases separately from the same vendor. Why paying for Art Full Text and Education Full Text separately if you can afford Wilson Select Plus? If you have them all via one interface, say FirstSearch, all your Wilson subscriptions are FT. If you already have general ones, it may not be worth it to pay for subject ones from the same vendor. Of course, there are exceptions, e.g. EBSCO’s Business Source.
Next, the embargo issue. FT embargo means the delay of availability of FT articles. We can see the amazing differences in handling embargo by different vendors. 5 vendors were compared: EBSCO, Gale, LexisNexis, ProQuest, and Wilson. All have more or less embargoes, as of 8/02.
Difference #1. Publicize embargo None wants to publicize the info, but if you try hard, you can find out: EBSCO: on both database site (for users) and company site title lists (for librarians); Gale: on company site, not on database site; LexisNexis: on database site, not on company site; ProQuest: on company site, not on database site; Wilson: neither.
Difference #2: Percentage of embargoed titles According to the data provided by vendors themselves, from around 5% average of one vendor (Gale) to around 30% average of another (EBSCO).
EBSCO (as of 8/02) DatabaseFT totalEmbargo% of Embg Academic Search E % Biz Source % Hlth Src: Nursing %
Gale (as of 8/02) databaseFT totalEmbargo% of embg Biz & Comp Ctr % Expanded Academic % InfoTrak OneFile %
LexisNexis: not countable; ProQuest: not countable; Wilson: not available.
Note: The real percentage of embargoed titles are actually higher than what we just saw, because the total FT titles include ceased titles that are no longer updated.
Difference #3: the same periodical is not embargoed everywhere. The vendors/aggregators tell us the embargo is imposed by publishers---something out of their control. But we found journals with 12- month embargo in one place could have current issue FT in another place.
Child Development, Journal of Interdisciplinary History, Journal of Pacific History, TDR (The Drama Review). As of 8/02, the above 4 journals have 12- month embargo with EBSCO, but have current issue FT with Gale.
Similarly, Renaissance Quarterly has 3-year embargo on Gale, but has current FT on ProQuest’s Periodical Abstracts. Journal of Interdisciplinary History does not have Summer 02 FT on EBSCO, but does have FT on Wilson. If the embargo is imposed by publisher, why it is not imposed everywhere?
Difference #4: Have citations or not before FT available? First of all, if the embargo period is 6 months or shorter, all vendors do not add citations or bibliographic information. The difference mainly lies in embargo longer than 6 months, typically 12 months, or longer.
EBSCO: Has citations; Gale: Has citations; LexisNexis: does not apply; ProQuest: does not have citations; Wilson: does not have citations.
Citation before FT examples as of 9/02. Gale has the citation. E.g., Renaissance Quarterly has citations before FT available. Periodical Abstracts does not have citation. E.g., Journal of Sport & Social Issues the most recent available was 5/01. EBSCO and Wilson comparison. Journal of Urban Affairs is on both. On 9/11/02, the same search could retrieve 7/02 issue as the most recent on EBSCO without FT, but could only retrieve 4/02 issue with FT as the most recent on Wilson.
Embargo conclusions: Embargoed percentage differs greatly, with EBSCO probably has the highest. The fact that same titles embargoed on one place have FT on another probably reveals the secret that embargo may not be simply imposed by publishers-- it could be related to the price the vendor and library are willing to pay. When there is embargo, some vendors load citations before FT, others let us believe that embargoed issues do not exist.
Other little secret found through vendor comparison. The overlap between same kind of databases, say general databases by different vendors, is very little. EBSCO’s Academic Search Elite, Gale’s Expanded Academic ASAP, ProQuest’s Periodical Abstracts, and Wilson’s Wilson Select Plus do not overlap much. Possible reason: more and more exclusive deals between aggregators and publishers. Price for the libraries and users: no more “one-stop shop”.
Where can we find the “secrets”? Vendors’ Web sites, such as Download the FT lists in MS Excel (if no Excel file available, download the Text or CSV file, and convert them into Excel). With some basic Excel tricks, you can manipulate the data and get the analysis you want.