How to Evaluate Database Content:
Evaluating a database for content is a matter of describing the literature covered by the database and how the database covers it.
When evaluating the literature covered by the database, you are asking what fields of research are covered, what material types are covered (articles, books, chapters of books, essays in collections, conference proceedings and other kinds of specialized report), and what is the publication date range.
When evaluating how a database covers a specific literature, you are asking: what level of indexing is provided, are there abstracts and how detailed are they, and if there are links to full text is it simply text or is it a facsimile of the original.
These question constitute a what, when and how of database content.
1. Help screens. Help screens are an underused part of most databases. They can give you a general idea of the literature covered, the formats covered and time coverage related to indexing, abstracting and full text coverage. The describe the database records by letting you know what is covered by different database indexes.
2. Look at several database records. Do a simple broad keyword search (such as searching on "music") and examine several records. You will immediately understand a great deal about the database. Try repeating your search with different pre-search limits related to format to get a sense of how uniform indexing is across different formats. In particular try limiting to book chapter. When you do so you should get a record which indicates which book the chapter came from. You will need this information to find the chapter.
3. Broad searches and post-limiting. Do a simple broad keyword search and then try different post-search limits. If a database claims to index materials back to 1890 and you add a post-search limit of 1980 to present to your results and find the number of results is almost the same, then you know that not many materials from that period are indexed. If you applied a post-search limit of Only Full Text and found your results reduced to 10% of the original, you have a good idea of extend of full text coverage.
4. Publication lists. Many databases have detailed, that is every single source indexed, lists of publications covered. A rather limited amount of browsing of these lists will give you an approximation of indexing coverage, abstracting coverage and full text coverage. These list often allow you to search by "word in title" which you can use in a non-music database to get a feel for how much music literature is covered.
5. Specialized subsets of a database. Some databases have specialized collections which are part of the database. An image database which only covers the drawings which appear in articles indexed in the database may not be very useful, but a separate collection of reviews which appeared in Variety in a theater database could be very useful.
6. Who created the database (not the interface). Database are sometimes the work of national organizations or federal agencies. ERIC is produced by the Dept. of Education. Some database have a connection to an agency, but may not be produced by them. This can be true in the case of some of the databases which contain an elaborate thesaurus created by an agency.
How to Evaluate an Interface:
Always remember that the content of a database and its user interface are separate things. You will notice many similarities between the databases provided by a specific vendor (EBSCO or ProQuest) which will make it easy in evaluating the interface of one of the database they provide. You job will be noticing the aspects of the database which seem to be specific to the content of that database.
1. Look at the keyword indexes in the Advanced Search Space. If you don’t understand any, look at a database record. You can also try some simple searches in that index, guessing what it might index and see if you retrieve any records. Examine the records to see what field contained your search term.
2. Look at pre-search limits. These in and of themselves will tell you what material types are covered. If you don't understand one ("technical report"), then do a simple broad keyword search with a pre-search limit of that material type and examine some of the records you retrieved.
3. Look at post-search limits. A database can't do a post-search limit on a features it doesn't contain, such as full text links.
4. Look at the browse indexes. If you don’t understand any, try an abc search to see what they contain. If you still don't understand them, execute a search on something you find in the browse index and look in one of the records retrieved to see where it appears in the record.
5. Is there a thesaurus or similar authorized subject heading list? You should always try the thesaurus to see how easy you find it to use. Thesauri are very powerful tools, but some are quite complex.
6. Are there other special tools such as an index specific to geographical subject headings?
7. Are there special subsets of the database and if so, how are they setup (as keyword or browse index)? These include image databases.
8. Is cited reference searching available?
9. Is multi-database searching available? You should try look at the indexes for a couple of databases and once multi-database searching is turned on, check to see which indexes are lost. Also not if pre-search limits are retained for both databases.
10. Is there a search history function? You should try this out after a couple of simple searches, these can be set up in different ways.