“A citation is the textual form in which a document refers to another document. A proper publication features a references section: each entry in this section is a citation. Citation indexing consists into the indexing of the text of each such entry. (SMEAL, retrieved 15 September 2006.”)
See also: Indexing
It is very important that teachers (or some other facilitators) explain how such an engine works and/or to engage learners in a formal activity that makes them learn. Most people (including university students) do not take enough time to understand how such specialized engines work.
Most commercial electronic journal portals also show increasingly sophisticated citation features. Most often you can list the references of a given article and see who cited the article. Cross-references may extend to other vendors. One also can find similar articles. There are interface novelties, e.g. Sage includes a visual citation map.
2.1 CiteSeer and Smeal
CiteSeer is both a citation engine and a digital library
CiteSeer is based on the SmealSearch engine. The citation engine offers the following main functionalities:
- Search citations with different query terms (e.g. an author name).
- The result will show references with author, title, date, journal/volume etc.
- Details for each result can be consulted in the context page.
The digital library engine allows
- to search the documents database with keywords.
- The sortable results include a title, a link, a context for the search keywords, number of citations, etc.
2.2 ACM Portal
The Guide to computing literature allows to search publications. Each entry found will display:
- Authors (with links)
- Collaborative colleagues (people an author with whom other articles have been published. Note: this is approximative since it will show articles from authors who have the same name.
- A link to similar articles (this is very useful)
The ACM digital library (indexing its own publications) adds:
- Citings (who has cited this article)
- What articles have been consulted by other people who consulted this article (peer-to-peer reading, see social navigation).
- A hierarchical tree of index terms
- Design terms
- CiteULike is a free web-based service to help academics to share, store, and organize the academic papers they are reading.
- Insertion is easy: Adding an article to the personal library is a one click operation. The system automatically extracts the citation details.
- Users can folksonomy kinds of tags.
Search of article titles, tags, author names, abstracts and journal titles with keywords (tags). The results for title and abstract search lists:
- article names and author
- tags for each article
- lists recent articles
Entries about articles give the following information
- Clickable author names
- Access button to the article
- ID tags used
- Clickable people who have the article in their "library".
- Visualization of related articles with a TouchGraph applet (can hang your browser - DSchneider 15:18, 21 September 2006 (MEST))
- BibTex export of the reference
3.2 Citation indexes
- ACM Portal, (Access restricted) in part