Exam 12: Experiments With More Than One Independent Variable

RESEARCH STUDY 12.3: 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."

You read an article that states, "How well you remember different types of information depends on the context in which you learned them." Based on this information, what else is true about this study?

RESEARCH STUDY 12.1: 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. In Dr.Elder's study, how many possible main effects exist?

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

Dr.Rhodes notices an interaction in his factorial study.In describing this, which statement might he use to explain the link between Independent Variable A and Independent Variable B in predicting the dependent variable?

Why are factorial designs useful in testing theories?

Dr.Gavin is conducting a 2 × 4 independent-groups factorial design.How many cells are in his design?

RESEARCH STUDY 12.1: 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 best describes Dr.Elder's study?

RESEARCH STUDY 12.1: 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. To make his study a 2 × 2 × 3 factorial design, which of the following would Dr.Elder need to do?

RESEARCH STUDY 12.1: 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. By examining the marginal means, it appears that in this study:

A simple difference is also called:

RESEARCH STUDY 12.1: 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. In graphing the results of his study, which of the following would be true for Dr.Elder?

RESEARCH STUDY 12.3: 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?

Dr.Gavin is conducting a 2 × 4 independent-groups factorial design.How many main effects will Dr.Gavin need to examine?

Imagine that you are reading a journal article and you see the following sentence: "The study used a 2 × 2 × 4 design." Based on this sentence alone, you would know which of the following pieces of information?

If a person describes the results of a study to you by saying that there is a zero difference in one condition but a large difference in another condition, the person is most likely describing which of the following?

Explain why researchers care about interactions more than main effects.

RESEARCH STUDY 12.3: 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 the data table alone, discuss whether Dr.Lopez should conclude that an interaction exists in his study.