Truncation allows a user to search various word endings by adding a character like * at the end of a word root. Education* would include educational for example. Most databases and catalogs use the asterisk as the truncation feature.
Adjacency makes words be side by side rather than anywhere in the expanded citation, bibliography etc. The most common adjacency is the quotation marks. "teacher evaluation" assures that the words are next to each other and should cut down on unrelated citations.