Polls allow you to quickly survey student understanding of a concept.
Let them show what they know, then address it in your teaching.
The poll results are from the same group of students who had two library instruction classes, with a month in between each class.
9 out of 20 students clearly do not understand a basic search concept: the more keywords you connect with AND, the fewer hits you get. Of the 11 students who do understand that basic search concept, only 6 understand that the * will pick up alternate endings of words which will yield more search results.
13 out of 14 students clearly remember practicing the basic search concept of Boolean AND. 3 of those 13 required more practice with the concept of truncation.