In Search of: Bloom's Taxonomy
Situation
There has been a great deal of focus on elementary education lately, especially with the release of new findings showing American students faring poorly against international peers in reading and math. These and similarly troubling findings have highlighted the problems that can occur from the "teaching to the test" process that has increased in the wake of No Child Left Behind Act mandates.
In addition, dissatisfaction with pegging effectiveness of education to students' performance on standardized tests has fueled an interest in a different approach to education in which students are encouraged to develop their own understanding and apply what they learn analytically and creatively.
Perhaps the best-known classification of learning objectives in education that feeds into that goal is Bloom's Taxonomy, a system developed in the 1950s and revised in the years since. Suppose a researcher was interested in performing a meta-analysis in which her first step was to obtain a list of records in the PsycINFO database that specifically mention the taxonomy?
Build Your Search
Our usual approach to a search is to use the thesaurus as a starting place, but in this case, we are interested not so much in a focused topic search as in finding literally all of the research we can that mentions Bloom's Taxonomy.
APA PsycNET Platform
Let's begin with the APA PsycNET platform and perform a Keywords search, which searches the title, the index terms, and the keyword fields. Second, we perform an Any Field search, which also searches the abstract, which can be very useful in a broader search, and the grants and sponsorship and tests and measures fields. Note that the Any Field search does not search the cited references.
An APA PsycNET Keywords search:

Results screen:

An APA PsycNET Any Field search:

Results screen:

Note the difference between the numbers of results. There are well over double the results when a search of the abstract is included.
Finally, to expand our results, we add a proximity search in a third step, to add records where the words "Bloom's" and "taxonomy" appear within four words of each other.

Results screen:

This search picks up an additional 60 records.
CSA Illumina Platform
In our second iteration of this search, we're going to run what looks like the same two searches, but we'll do so using the CSA Illumina platform.
A CSA Illumina Keywords search:

Results screen:

A CSA Illumina Anywhere search:

Results screen:

In both cases, you see the results are considerably higher on the CSA Illumina platform than they were in the APA PsycNET searches. Why? Because CSA Illumina searched in different places. A Keywords search on that platform automatically includes an abstract search, and an Anywhere search automatically includes the cited references.
In a third iteration of the search, we can continue with CSA Illumina and add the proximity operator "within" to include results in which the words appear within a designated number of spaces of each other.
For example, let's show that with our broadest set of results:
Results screen:

This screen yields our most inclusive set of results.
Why are the same or almost the same fields categorized differently? The difference is essentially philosophic and has to do with whether the platform designers sought a more comprehensive or a more focused search. Each has its strengths, and the same or roughly the same results can be obtained on most platforms by grouping different index searches and using different Boolean combinations, wild cards, or proximity operators.
PsycINFO is available on four major platforms, CSA Illumina, OvidSP, Ebscohost, and APA PsycNET. The former two take the more expansive approach, whereas the latter two take the more focused approach. If you know what each index actually searches, you can craft your search to fit your needs.
Below is a sample of records obtained from the final APA PsycNET search:

