Question: Why are only some truncated phrases expanded when being searched in Basic search on ProQuest?

Answer: When searching truncated phrases in Basic search, the truncated phrase is initially being checked against the subject terms available in the database(s) of interest. This will then retrieve the relevant terms, and if the plurals option is also activated, these are included.

The following example illustrates this:
"educational technolog*" 

- the ProQuest platform checks to see if this is a subject term. If it is, it is then added to the search query, and if plurals are activated, these are also included, so that the final search query will be:

(“educational technology” or “educational technologies”)

This revised search string will then search across all available data fields. The platform also surrounds these expanded terms with parens to ensure that the actual search is not changed as regards order of precedence with Boolean operators.

You will also see the following explanatory message:

By selecting the [STRICT] “educational technolog*” hyperlink, your original search phrase is searched instead of the revised search string.