Week Three Discussion One 3.1

Variables and Confoundings
A social psychologist wants to test the implications of a theory of personal space. He thinks that people will differ in their reaction to others who intrude in their personal space depending on the perceived status of the intruder. Specifically, he predicts that people who are viewed as having higher status in some way will be permitted to move closer than those who are not viewed as having higher status. Thus, the investigator arranges to conduct an experiment in which he uses undergraduate students as participants and manipulates status by controlling the manner in which individuals are introduced to a participant. Confederates of the researcher (all male graduate student research assistants) are introduced as observers in one of three ways, as: “an undergraduate student working for the psychology department”; “an undergraduate honors student working for me” (i.e., the faculty member); or “a graduate student working for me.” Prior to testing any participants, three different confederates are randomly assigned one of the three roles to play and subsequently keep that same role throughout the experiment. Students are scheduled in groups of three and are assigned randomly to one of the three introduction conditions when they appear for the experiment. Each participant is taken to a different small room with two chairs, supposedly to work on an experimental task. The psychologist introduces the confederates to participants while they are working on their tasks. After being introduced to each participant, the confederate-observer takes the second chair and places it within 6 inches of a participant, makes what looks like observations for 5 minutes, and then leaves. The confederate-observer actually measured how many participants moved their chairs away, even slightly, when he moved next to them. After many individuals are tested in this manner, the psychologist finds that significantly fewer people adjusted their seating position when the observer was introduced as a graduate student than when the observer was introduced as an undergraduate. There is no difference in the number of moves made by participants in the two conditions in which the observers were introduced as undergraduates. The investigator concludes that his hypothesis was supported.
What is the independent variable (and its levels) in this study?
What is the dependent variable?
Can you identify a confounding that threatens the internal validity of this experiment? Identify the confounding and explain why it is a threat to the study’s internal validity.
What specific control technique should the experimenter have employed in order to protect the internal validity of this experiment?