Exam 12: Experiments With More Than One Independent Variable

Dr. Elder was interested in the way people recognize objects as members of categories. For example, what makes us recognize a dog as being a dog and not a cat? More specifically, he was curious as to whether people think about categories in a more complex way if they contemplate an "opposite" category first. For example, does a person think more differently about the category of "southern" if they are also thinking about the category of "northern"? He is also curious as to whether people categorize differently if they are exposed to category members compared with generating category members. Dr. Elder has four groups of participants (with 30 people in each group). In Group A, participants were told to cut out pictures of dogs and cats from magazines. In Group B, participants were told to cut out pictures of just dogs from magazines. In Group C, participants were told to draw pictures of cats and dogs. In Group D, participants were told to draw pictures of just dogs. After doing this for 30 minutes, participants in all groups were asked to list the attributes that define the "dog" category. Having a higher number of attributes listed was considered to be an indication of thinking about the category in a more complex way. Dr) Elder also is curious as to whether categorization happens similarly for children as it does for adults. As such, he recruits a group of 10-year-olds and a group of 20-year-olds to participate in the study. The results are below. Based on the graphs above, why should Dr. Elder conclude that there is a three-way interaction?

To study the effects of physical discomfort on attention, Dr. Lopez conducted the following study: A group of participants were required to keep one hand submerged in cold water (52 degrees). Half of the participants kept their hand in the water for 2 minutes, and half of the participants kept their hand in the water for 4 minutes. In addition, half of the participants were given a placebo pill and told it would reduce the pain of the water (pain relief assumed). The other half were given a placebo pill and told that it would have no effect (no pain relief assumed). While their hands were in the water, participants were asked to watch a video where a ball is quickly passed between and underneath three cups. At the end of the video, participants were asked to indicate under which cup the ball could be found. Whether or not the participant picked the correct cup was recorded (as a measure of whether they were paying attention). The results are below. Using Dr. Lopez's study as an example, explain why an interaction can be described as "a difference in differences."

Imagine that you read the following passage in a popular magazine. Should you conclude that the original article found evidence of an interaction? Why is or isn't there evidence of an interaction? "One study had participants watch a crime show. Half the participants watched a documentary of a murder that took place in rural Virginia, while the other half watched a movie adaptation of the same murder. The effect of viewing a crime show on people's fear of being a victim of crime depends on the participants' sex, with women in general being more fearful regardless of which show they saw, whereas men reported more fear after watching the documentary."

Which of the following phrases might a person encounter in a popular media article that indicates an interaction?

Studies with one independent variable can show:

If a study describes the "difference in differences," what is the minimum number of variables the researchers were studying?

The phrase "especially for" would be used to describe which of the following results?

If a study has a difference in the differences, you know the study definitely has a:

In the case of a factorial design, another term for independent variable is:

Dr. Green is interested in conducting a 2 × 2 × 3 within-group factorial design, with 20 participants in each cell. How many participants does she need overall?

A simple difference is also called:

To study the effects of physical discomfort on attention, Dr. Lopez conducted the following study: A group of participants were required to keep one hand submerged in cold water (52 degrees). Half of the participants kept their hand in the water for 2 minutes, and half of the participants kept their hand in the water for 4 minutes. In addition, half of the participants were given a placebo pill and told it would reduce the pain of the water (pain relief assumed). The other half were given a placebo pill and told that it would have no effect (no pain relief assumed). While their hands were in the water, participants were asked to watch a video where a ball is quickly passed between and underneath three cups. At the end of the video, participants were asked to indicate under which cup the ball could be found. Whether or not the participant picked the correct cup was recorded (as a measure of whether they were paying attention). The results are below. Provide a graph of the possible interaction in Dr. Lopez's study and discuss whether Dr. Lopez should conclude that an interaction exists in his study.

Dr. Elder was interested in the way people recognize objects as members of categories. For example, what makes us recognize a dog as being a dog and not a cat? More specifically, he was curious as to whether people think about categories in a more complex way if they contemplate an "opposite" category first. For example, does a person think differently about the category of "southern" if they first think about the category of "northern"? He is also curious as to whether people categorize differently if they are exposed to category members compared with generating category members. Dr. Elder has four groups of participants (with 30 people in each group). In Group A, participants were told to cut out pictures of dogs and cats from magazines. In Group B, participants were told to cut out pictures of just dogs from magazines. In Group C, participants were told to draw pictures of cats and dogs. In Group D, participants were told to draw pictures of just dogs. After doing this for 30 minutes, participants in all groups were asked to list the attributes that define the "dog" category. Having a higher number of attributes listed was considered to be an indication of thinking about the category in a more complex way. The results of his study are below. Which of the following reasons is the most likely reason Dr. Elder conducted a factorial design?

What does the author of the textbook mean when she writes, "We don't live in a main effect world"?

Dr. Elder was interested in the way people recognize objects as members of categories. For example, what makes us recognize a dog as being a dog and not a cat? More specifically, he was curious as to whether people think about categories in a more complex way if they contemplate an "opposite" category first. For example, does a person think more differently about the category of "southern" if they are also thinking about the category of "northern"? He is also curious as to whether people categorize differently if they are exposed to category members compared with generating category members. Dr. Elder has four groups of participants (with 30 people in each group). In Group A, participants were told to cut out pictures of dogs and cats from magazines. In Group B, participants were told to cut out pictures of just dogs from magazines. In Group C, participants were told to draw pictures of cats and dogs. In Group D, participants were told to draw pictures of just dogs. After doing this for 30 minutes, participants in all groups were asked to list the attributes that define the "dog" category. Having a higher number of attributes listed was considered to be an indication of thinking about the category in a more complex way. Dr) Elder also is curious as to whether categorization happens similarly for children as it does for adults. As such, he recruits a group of 10-year-olds and a group of 20-year-olds to participate in the study. The results are below. Dr) Elder will need to examine main effects and interactions.

To study the effects of physical discomfort on attention, Dr. Lopez conducted the following study: A group of participants were required to keep one hand submerged in cold water (52 degrees). Half of the participants kept their hand in the water for 2 minutes, and half of the participants kept their hand in the water for 4 minutes. In addition, half of the participants were given a placebo pill and told it would reduce the pain of the water (pain relief assumed). The other half were given a placebo pill and told that it would have no effect (no pain relief assumed). While their hands were in the water, participants were asked to watch a video where a ball is quickly passed between and underneath three cups. At the end of the video, participants were asked to indicate under which cup the ball could be found. Whether or not the participant picked the correct cup was recorded (as a measure of whether they were paying attention). The results are below. Using Dr. Lopez's study as an example, explain why an interaction is often described by saying "it depends."

Explain why researchers care about interactions more than main effects.

Imagine that you are reading a journal article and you see the following sentence: "The study used a 2 × 2 × 4 design." Where are you likely to have encountered this sentence?

Dr. Elder was interested in the way people recognize objects as members of categories. For example, what makes us recognize a dog as being a dog and not a cat? More specifically, he was curious as to whether people think about categories in a more complex way if they contemplate an "opposite" category first. For example, does a person think more differently about the category of "southern" if they are also thinking about the category of "northern"? He is also curious as to whether people categorize differently if they are exposed to category members compared with generating category members. Dr. Elder has four groups of participants (with 30 people in each group). In Group A, participants were told to cut out pictures of dogs and cats from magazines. In Group B, participants were told to cut out pictures of just dogs from magazines. In Group C, participants were told to draw pictures of cats and dogs. In Group D, participants were told to draw pictures of just dogs. After doing this for 30 minutes, participants in all groups were asked to list the attributes that define the "dog" category. Having a higher number of attributes listed was considered to be an indication of thinking about the category in a more complex way. Dr) Elder also is curious as to whether categorization happens similarly for children as it does for adults. As such, he recruits a group of 10-year-olds and a group of 20-year-olds to participate in the study. The results are below. Based on the graphs above, Dr. Elder should conclude which of the following?

To study the effects of physical discomfort on attention, Dr. Lopez conducted the following study: A group of participants were required to keep one hand submerged in cold water (52 degrees). Half of the participants kept their hand in the water for 2 minutes, and half of the participants kept their hand in the water for 4 minutes. In addition, half of the participants were given a placebo pill and told it would reduce the pain of the water (pain relief assumed). The other half were given a placebo pill and told that it would have no effect (no pain relief assumed). While their hands were in the water, participants were asked to watch a video where a ball is quickly passed between and underneath three cups. At the end of the video, participants were asked to indicate under which cup the ball could be found. Whether or not the participant picked the correct cup was recorded (as a measure of whether they were paying attention). The results are below. Imagine that Dr. Lopez decides to add another variable to his study. He is curious as to whether the results of the study vary based on sex (male and female). Using factorial notation, describe Dr. Lopez's study. Given this new study design, how does this change the number of cells, main effects, and interactions in Dr. Lopez's study?