A study by Jones, Gorman, and Schroeder (1989) sought to compare the effects of two different career interest inventories on the amount of time spent on occupational exploration in the career library. The participants were 68 college students who responded to a career center invitation to take an interest inventory to help them with their career choices. When the students appeared for their appointment at the career center a research assistant gave them at random, one of two inventories to fill out. Each inventory was followed by identical instructions to feel free to explore the resources in the carcer library. After the students filled out the inventory, the research assistant unobtrusively recorded how much time each student spent exploring the resources of the library. What was the researcher's independent variable? What is the dependent variable? IV DV, null, directional, non directional