In this paper, we triangulate evidence for five misconceptions concerning binary search trees and hash tables. In addition, we design and validate multiple-choice concept inventory questions to measure the prevalence of four of these misconceptions. We support our conclusions with quantitative analysis of grade data and closed-ended problems, and qualitative analysis of interview data and open-ended problems. Instructors and researchers can inexpensively measure the impact of pedagogical changes on these misconceptions by using these questions in a larger concept inventory.