Complete the Week 4 Homework Exercise.
Week 4 Homework Exercise
Answer the following questions in 25 to 50 words each (where applicable), covering material from Ch. 8–10 of Methods in Behavioral Research:
1. What are the defining features of an experiment? What types of variables may be included?
2. What is a confounding variable? Why do researchers try to eliminate confounding variables?
3. What are the differences between the different types of research designs?
4. Pretest effects can be assessed with a research design called _______.
5. A researcher is interested in studying the effects of story endings—predictable endings or surprise endings—on preference ratings. He randomly assigns participants into two groups—predictable ending or surprise ending—and instructs them to read the story and provide preference ratings. The experimenter’s variation of story endings is a __________ (straightforward or staged) manipulation.
6. A researcher was interested in investigating the vocabulary skills of sixth graders in a program for gifted students. She gave a group of participants a test of vocabulary that was aimed at the seventh-grade level. She quickly discovered that there was limited variability in the scores because nearly all the students answered 90% or more of the questions correctly. This outcome is called a _______ effect.
7. A researcher is investigating verbal behavior among introverts and extroverts. The researcher first tests participants and classifies them as either introverted or extroverted. She then randomly assigns participants to a high-anxiety or a low-anxiety social group and observes the number of words spoken by participants. The researcher wants to learn more about the effects of both personality style (introversion or extroversion) and social situation (high or low anxiety) on verbal behavior. In this case, verbal behavior is defined as the number of verbal communications uttered within a five-minute observation period. What type of design is this? Provide an example of a possible main effect that might emerge from this study. Additionally, provide an example of a possible interaction that might emerge.