PSYCH 303- Research Methods Final (Exam 5)

Observer bias threatens internal validity because ______ and threatens construct validity because _______.

-an alternative explanation exists -the ratings are inaccurate

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. (listed cutting out picture, drawing pictures) Dogs and cats: 15 , 9 Dogs only: 7 , 6 How many participant variables exist in Dr. Elder's study?

0

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

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. (listed cutting out picture, drawing pictures) Dogs and cats: 15 , 9 Dogs only: 7 , 6 In Dr. Elder's study, how many possible main effects exist?

2

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. (listed cutting out picture, drawing pictures) Dogs and cats: 15 , 9 Dogs only: 7 , 6 To determine if there is a main effect for type of activity, Dr. Elder must examine how many marginal means?

2

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. In the study described above, Dr. Elder will need to examine how many two-way interactions?

3

A researcher wants to run a 2 x 3 mixed factorial design. The first factor is within-subjects. The second factor is between-subjects. If the researcher wants 20 observations per cell, how many participants will he need in total?

60

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

8

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. (listed cutting out picture, drawing pictures) Dogs and cats: 15 , 9 Dogs only: 7 , 6 In graphing the difference between the differences, which of the following values would Dr. Elder use?

9

In previous studies, Dr. Schulenberg has established that finding meaning in one's everyday work activities can lead to greater success in the workplace (e.g., productivity, creativity). He is curious as to whether this can happen in the college classroom. Specifically, he is curious whether finding meaning in one's classroom experience can lead to greater academic performance. In the spring semester, he has his teaching assistant randomly assign half the class to write a paragraph each class period about how the material has meaning for their lives (meaning group). The other half writes a paragraph about what they did to prepare for class (preparation group). He does not know which of his students are writing which paragraph, and the students are not aware they are responding to different writing assignments. To measure academic performance, he gives the students a midterm essay exam and a final exam. Which of the following aspects of Dr. Schulenberg's study allows him to prevent observer bias?

Ensuring the person grading the exams is unaware of each students writing group

Random selection enhances ________ and random assignment enhances ________.

External validity, internal validity

Dr. Lonsbary is a cognitive psychologist who is curious about how mood affects memory. She recruited 60 high school students and divided them into three groups. Group A listened to a five-minute piece of music intended to make them feel happy (a song titled "Don't Worry, Be Happy"). Group B listened to a five-minute piece of music intended to make them feel sad (a song titled "Alone Again"). Group C listened to no music and instead was asked to sit quietly for five minutes (thought to make them feel neutral). When a participant would come to her laboratory, Dr. Lonsbary would greet the participant and then ask him or her to draw a card. Participants who drew a 1, 2, or 3 were assigned to Group A. Participants who drew a 4, 5, or 6, were assigned to Group B. Participants who drew a 7, 8, or 9, were assigned to Group C. The participants were then given an unlabeled CD to listen to based on their group assignment. The CD contained either the song selection or five minutes of silence. They were then escorted into a different room, where they were greeted by a research assistant who conducted the experiment. The research assistant sat the participants in front of a computer screen and told them that a list of 25 words would be displayed on the screen. They were instructed to listen to the CD with headphones while trying to memorize the list of words. All participants were given the same list of 25 words to remember. When five minutes had passed, the screen displayed a question asking them whether they felt happy, sad, or neutral. After the participant responded, a new screen was displayed asking them to type in all the words they could remember from the list of 25 words. All participants were given three minutes to type the words they remembered. Afterward, the participant was thanked and dismissed. In response to the mood question, a majority of Group A participants said they were happy, a majority of Group B participants said they were sad, and a majority of Group C participants said they were neutral in their mood. Dr. Lonsbary found the following results in response to the number of words remembered. Which of the following allows Dr. Lonsbary to conclude that she met the temporal precedence rule for causality?

Having people listen to music or silence before they wrote down the list of words they remembered

Dr. Kline, an environmental psychologist, conducts a study to examine whether visiting zoos causes people to have more positive attitudes toward environmental conservation. He asks a group of 45 people attending the zoo on a Saturday morning about their attitudes. He finds that 69% of the people report having a positive attitude after their visit. Which of the following is NOT true of Dr. Kline's study?

He does not have a dependent variable

According to the textbook, why is it important to study interactions?

Many outcomes in psychology are interactions

When reading popular press articles, why does the inclusion of participant variable information often denote a factorial design?

Participant variables are often used as moderators

In previous studies, Dr. Schulenberg has established that finding meaning in one's everyday work activities can lead to greater success in the workplace (e.g., productivity, creativity). He is curious as to whether this can happen in the college classroom. Specifically, he is curious whether finding meaning in one's classroom experience can lead to greater academic performance. In the spring semester, he has his teaching assistant randomly assign half the class to write a paragraph each class period about how the material has meaning for their lives (meaning group). The other half writes a paragraph about what they did to prepare for class (preparation group). He does not know which of his students are writing which paragraph, and the students are not aware they are responding to different writing assignments. To measure academic performance, he gives the students a midterm essay exam and a final exam. Imagine that in Dr. Schulenberg's study, he notes that all of the students do extremely well on the midterm exam. When he looks at the results of the final exam, he notices that all the students' exam scores went down. Given this information, which of the following threats might be present in his study?

Regression

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?

The effect of Variable A is mediated by Variable B

Dr. Gavin decides that instead of conducting a 2 x 4 independent-groups factorial design, he is going to conduct a 2 x 3 x 4 mixed factorial design. Which of the following things will NOT have to change?

The number of researchers needed

Neely is examining the graph of an interaction and sees that one line is flat and one line rises sharply to the right. Which of the following should Neely conclude?

There is a spreading interaction

Which of the following is NOT true of selection effects?

They are unimportant for interrogating internal validity

Which of the following is true of instrumentation threats?

They can be avoided with counterbalancing

Regression is especially problematic in which of the following situations?

When one group has an extremely high score at pretest

Using a matched-group design is especially important in which of the following cases?

When you have only a few people in your 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. (listed cutting out picture, drawing pictures) Dogs and cats: 15 , 9 Dogs only: 7 , 6 Which of the following best describes Dr. Elder's Study?

a 2' 2 crossed factorial design

When conducting an experiment, what is provided by the independent variable?

a comparison group

The mathematical way to describe an interaction is:

a difference in differences

In previous studies, Dr. Schulenberg has established that finding meaning in one's everyday work activities can lead to greater success in the workplace (e.g., productivity, creativity). He is curious as to whether this can happen in the college classroom. Specifically, he is curious whether finding meaning in one's classroom experience can lead to greater academic performance. In the spring semester, he has his teaching assistant randomly assign half the class to write a paragraph each class period about how the material has meaning for their lives (meaning group). The other half writes a paragraph about what they did to prepare for class (preparation group). He does not know which of his students are writing which paragraph, and the students are not aware they are responding to different writing assignments. To measure academic performance, he gives the students a midterm essay exam and a final exam. The study described above is an example of which of the following?

a double blind study

Dr. Lonsbary is a cognitive psychologist who is curious about how mood affects memory. She recruited 60 high school students and divided them into three groups. Group A listened to a five-minute piece of music intended to make them feel happy (a song titled "Don't Worry, Be Happy"). Group B listened to a five-minute piece of music intended to make them feel sad (a song titled "Alone Again"). Group C listened to no music and instead was asked to sit quietly for five minutes (thought to make them feel neutral). When a participant would come to her laboratory, Dr. Lonsbary would greet the participant and then ask him or her to draw a card. Participants who drew a 1, 2, or 3 were assigned to Group A. Participants who drew a 4, 5, or 6, were assigned to Group B. Participants who drew a 7, 8, or 9, were assigned to Group C. The participants were then given an unlabeled CD to listen to based on their group assignment. The CD contained either the song selection or five minutes of silence. They were then escorted into a different room, where they were greeted by a research assistant who conducted the experiment. The research assistant sat the participants in front of a computer screen and told them that a list of 25 words would be displayed on the screen. They were instructed to listen to the CD with headphones while trying to memorize the list of words. All participants were given the same list of 25 words to remember. When five minutes had passed, the screen displayed a question asking them whether they felt happy, sad, or neutral. After the participant responded, a new screen was displayed asking them to type in all the words they could remember from the list of 25 words. All participants were given three minutes to type the words they remembered. Afterward, the participant was thanked and dismissed. In response to the mood question, a majority of Group A participants said they were happy, a majority of Group B participants said they were sad, and a majority of Group C participants said they were neutral in their mood. Dr. Lonsbary found the following results in response to the number of words remembered. Dr. Lonsbary's study contains which of the following techniques designed to address a threat to construct validity?

a manipulation check

Dr. Lonsbary is a cognitive psychologist who is curious about how mood affects memory. She recruited 60 high school students and divided them into three groups. Group A listened to a five-minute piece of music intended to make them feel happy (a song titled "Don't Worry, Be Happy"). Group B listened to a five-minute piece of music intended to make them feel sad (a song titled "Alone Again"). Group C listened to no music and instead was asked to sit quietly for five minutes (thought to make them feel neutral). When a participant would come to her laboratory, Dr. Lonsbary would greet the participant and then ask him or her to draw a card. Participants who drew a 1, 2, or 3 were assigned to Group A. Participants who drew a 4, 5, or 6, were assigned to Group B. Participants who drew a 7, 8, or 9, were assigned to Group C. The participants were then given an unlabeled CD to listen to based on their group assignment. The CD contained either the song selection or five minutes of silence. They were then escorted into a different room, where they were greeted by a research assistant who conducted the experiment. The research assistant sat the participants in front of a computer screen and told them that a list of 25 words would be displayed on the screen. They were instructed to listen to the CD with headphones while trying to memorize the list of words. All participants were given the same list of 25 words to remember. When five minutes had passed, the screen displayed a question asking them whether they felt happy, sad, or neutral. After the participant responded, a new screen was displayed asking them to type in all the words they could remember from the list of 25 words. All participants were given three minutes to type the words they remembered. Afterward, the participant was thanked and dismissed. In response to the mood question, a majority of Group A participants said they were happy, a majority of Group B participants said they were sad, and a majority of Group C participants said they were neutral in their mood. Dr. Lonsbary found the following results in response to the number of words remembered. Dr. Lonsbary's decision to randomly assign participants to the three groups was done to avoid which of the following?

a selection effect

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, they are most likely describing which of the following?

a spreading interaction

Dr. Morimoto is curious as to whether exposing people to violent video games causes them to be more aggressive. He assigns half his participants to play a video game for five minutes and the other half to play for seven minutes. He finds that there is no relationship between playing the game longer and being more aggressive. What might be to blame for this null effect?

a weak manipulation

Adding a comparison group would allow one to show that the intervention had :

an effect above and beyond the normal effects of maturation.

Random assignment avoids selection effects since each participant has:

an equal chance of being assigned to either condition.

In a study that only lasts a few minutes, _____ isn't usually an issue. There was no mention of participant loss.

attrition

The rise in scores on the second test may be due to the loss of these extreme scores, which is ______

attrition

Dr. Sanderson is curious as to whether exposing people to violent video games causes them to be more aggressive. She assigns half her participants to play a violent video game for 5 minutes and the other half to play the same game for 25 minutes. Afterward, she has them play a board game and has a well-trained coder determine whether they are very aggressive in their playing style, barely aggressive, or not at all aggressive. She finds that a vast majority of her participants, regardless of group assignment, are rated as very aggressive. This outcome would be known as a/an:

ceiling effect

Adding more participants to a study reduces the impact of individual differences within groups and will increase the ______

chance of finding differences between groups

instrumentation: the raters, who are the measuring instrument, are______

changing over time

Dr. Whetstone is curious about how self-esteem changes as a result of a new counseling program. She is concerned about testing threats in her study. Which of the following would you NOT recommend to her as a way to address this type of threat?

collecting pretest data twice

A ________ can be used to control for maturation threats.

comparison group (the changes in the treatment group that differ from those in the comparison group can be ascribed to the treatment.)

The group that represents "no treatment" or the neutral condition is the ______..

control group

A variable that could be a nuisance variable is held constant and called a _______.

control variable.

Which of the following things CANNOT be done to reduce the effect of individual differences?

decrease power

An interaction means there is a ______.

difference in the differences.

Dr. Lonsbary is a cognitive psychologist who is curious about how mood affects memory. She recruited 60 high school students and divided them into three groups. Group A listened to a five-minute piece of music intended to make them feel happy (a song titled "Don't Worry, Be Happy"). Group B listened to a five-minute piece of music intended to make them feel sad (a song titled "Alone Again"). Group C listened to no music and instead was asked to sit quietly for five minutes (thought to make them feel neutral). When a participant would come to her laboratory, Dr. Lonsbary would greet the participant and then ask him or her to draw a card. Participants who drew a 1, 2, or 3 were assigned to Group A. Participants who drew a 4, 5, or 6, were assigned to Group B. Participants who drew a 7, 8, or 9, were assigned to Group C. The participants were then given an unlabeled CD to listen to based on their group assignment. The CD contained either the song selection or five minutes of silence. They were then escorted into a different room, where they were greeted by a research assistant who conducted the experiment. The research assistant sat the participants in front of a computer screen and told them that a list of 25 words would be displayed on the screen. They were instructed to listen to the CD with headphones while trying to memorize the list of words. All participants were given the same list of 25 words to remember. When five minutes had passed, the screen displayed a question asking them whether they felt happy, sad, or neutral. After the participant responded, a new screen was displayed asking them to type in all the words they could remember from the list of 25 words. All participants were given three minutes to type the words they remembered. Afterward, the participant was thanked and dismissed. In response to the mood question, a majority of Group A participants said they were happy, a majority of Group B participants said they were sad, and a majority of Group C participants said they were neutral in their mood. Dr. Lonsbary found the following results in response to the number of words remembered. Dr. Lonsbary is considering doing a follow-up study in which instead of asking participants to listen to music to induce mood, she has them write either a story about a character who just won the lottery or a story about a character who just experienced the death of their spouse. This change in the mood variable is designed to enhance the study's:

external validity

Correlation is not a term used in describing the results of a strictly ______ study, though it may be used within the same article.

factorial

Independent variables can also be called_______.

factors

Which of the following threats to internal validity CANNOT occur in just any study?

history threats

Manipulation checks help researchers measure:

how well their manipulation worked.

Selection effects can lead to a confounded experiment, but would not ____.

increase variability within groups.

Dr. Lonsbary is a cognitive psychologist who is curious about how mood affects memory. She recruited 60 high school students and divided them into three groups. Group A listened to a five-minute piece of music intended to make them feel happy (a song titled "Don't Worry, Be Happy"). Group B listened to a five-minute piece of music intended to make them feel sad (a song titled "Alone Again"). Group C listened to no music and instead was asked to sit quietly for five minutes (thought to make them feel neutral). When a participant would come to her laboratory, Dr. Lonsbary would greet the participant and then ask him or her to draw a card. Participants who drew a 1, 2, or 3 were assigned to Group A. Participants who drew a 4, 5, or 6, were assigned to Group B. Participants who drew a 7, 8, or 9, were assigned to Group C. The participants were then given an unlabeled CD to listen to based on their group assignment. The CD contained either the song selection or five minutes of silence. They were then escorted into a different room, where they were greeted by a research assistant who conducted the experiment. The research assistant sat the participants in front of a computer screen and told them that a list of 25 words would be displayed on the screen. They were instructed to listen to the CD with headphones while trying to memorize the list of words. All participants were given the same list of 25 words to remember. When five minutes had passed, the screen displayed a question asking them whether they felt happy, sad, or neutral. After the participant responded, a new screen was displayed asking them to type in all the words they could remember from the list of 25 words. All participants were given three minutes to type the words they remembered. Afterward, the participant was thanked and dismissed. In response to the mood question, a majority of Group A participants said they were happy, a majority of Group B participants said they were sad, and a majority of Group C participants said they were neutral in their mood. Dr. Lonsbary found the following results in response to the number of words remembered. What type of design did Dr. Lonsbary use in her study?

independent groups design

Selection effects only apply to _________ designs.

independent-groups

If the study's results show an interaction, the _______ is the most important effect.

interaction itself

In an experiment, researchers:

manipulate one variable and measure another.

Pilot studies help researchers test out a :

manipulation before using it in their study of primary interest.

Floor effects are a special case of ______ and________, not one of the three most common threats.

manipulations and insensitive measures

Identifying Factorial Designs in Popular Press Articles — Peer-reviewed journals publish _________, so this would not be a cue specific to a factorial study.

many types of studies

Which of the following research designs is used to address possible selection effects?

matched-groups designs

Spontaneous remission in clinical studies is an example of which of the following threats to internal validity?

maturation

Table 10.2 indicates that when d = .050, the effect size is _________.

moderate/medium

An interaction of two independent variables allows researchers to establish whether or not a variable is a ______.

moderator

Double-blind studies can control for _____ and _______, but this wouldn't help with the contribution of individual differences to within-group variability.

observer effects and demand characteristics

Since there is a main effect for both variables, the lines would be _______, and since there is no interaction, the lines would be ________.

parallel, parallel

Dr. Acitelli studies sleep and sleep disorders. She is curious as to whether falling asleep in front of a television set causes people to fall asleep more slowly than falling asleep without watching TV. She recruits a sample of 60 middle-aged women from a local church who reported no history of sleep problems. She creates three conditions. All participants come to the sleep lab for three nights in a row and experience all three conditions. In the first condition (A), participants fall asleep in front of a television that is off. In the second condition (B), participants fall asleep in front of a television that is turned on to the same 24-hour news channel. In the third condition (C), participants fall asleep in front of a television that is turned on to the same 24-hour news channel but is muted. With the use of an electroencephalograph (EEG), the researcher measures how long it takes participants to fall asleep. Given that Dr. Acitelli's participants have agreed to participate for three nights each, which type of counterbalancing should she use?

partial counterbalancing

A repeated-measures design is a type of within-groups design in which:

participants are measured on a dependent variable after exposure to each level of the independent variable.

Dr. Lonsbary is a cognitive psychologist who is curious about how mood affects memory. She recruited 60 high school students and divided them into three groups. Group A listened to a five-minute piece of music intended to make them feel happy (a song titled "Don't Worry, Be Happy"). Group B listened to a five-minute piece of music intended to make them feel sad (a song titled "Alone Again"). Group C listened to no music and instead was asked to sit quietly for five minutes (thought to make them feel neutral). When a participant would come to her laboratory, Dr. Lonsbary would greet the participant and then ask him or her to draw a card. Participants who drew a 1, 2, or 3 were assigned to Group A. Participants who drew a 4, 5, or 6, were assigned to Group B. Participants who drew a 7, 8, or 9, were assigned to Group C. The participants were then given an unlabeled CD to listen to based on their group assignment. The CD contained either the song selection or five minutes of silence. They were then escorted into a different room, where they were greeted by a research assistant who conducted the experiment. The research assistant sat the participants in front of a computer screen and told them that a list of 25 words would be displayed on the screen. They were instructed to listen to the CD with headphones while trying to memorize the list of words. All participants were given the same list of 25 words to remember. When five minutes had passed, the screen displayed a question asking them whether they felt happy, sad, or neutral. After the participant responded, a new screen was displayed asking them to type in all the words they could remember from the list of 25 words. All participants were given three minutes to type the words they remembered. Afterward, the participant was thanked and dismissed. In response to the mood question, a majority of Group A participants said they were happy, a majority of Group B participants said they were sad, and a majority of Group C participants said they were neutral in their mood. Dr. Lonsbary found the following results in response to the number of words remembered. Which of the following is an independent variable in Dr. Lonsbary's study?

participants mood

Testing threats involve ________ whereas instrumentation threats involve ________.

participants; measurements

Dr. Bloedorn is a health psychologist who researches nutrition. She is curious as to whether a new drink additive will help people consume fewer calories during a meal. The drink additive is a white, odorless, tasteless powder that a person can add to any drink. She collects a random sample of 63 overweight students on campus and measures the calories they eat during lunch, using a bomb calorimeter. She then gives this additive to the same 63 participants to use at dinner and measures how many calories they eat (again, using the bomb calorimeter). The addition of a group that does not use the drink additive but adds a similar-looking substance that they think is the additive would help Dr. Bloedorn address which of the following threats to internal validity?

placebo effects

When the control group is exposed to an inert treatment such as a sugar pill, it is called a

placebo group

For full counterbalancing, all the _______ must be used.

possible

he ability for a study to reveal a statistically significant difference between the levels of an independent variable when one truly exists is known as:

power

Which of the following is a threat to internal validity found in within-groups designs but not in independent-groups designs?

practice effects

_______ are one of the possible problems in within-groups designs, as the participants respond to each independent variable more than once.

practice effects

Experiments use random assignment to avoid which of the following?

selection effects

Disadvantages of Within-Groups Design — That extraneous differences are held constant is a _______, not a weakness.

strength

Attrition is not a threat if it occurs uniformly across both groups, but if it is _________, it becomes a threat.

systematic

insensitive measures: the scale does not have the precision to detect ______

the differences between two treatments

An author might use all of the following methods to indicate statistical significance EXCEPT:

the inclusion of a graph

In interactions the effect depends on:

the level of another vairable

Marginal means are a way of looking at:

the main effect of one variable.

Instrumentation threat occurs when:

the pretest and posttest are not sufficiently equivalent.

All of the following are true of ceiling and floor effects EXCEPT:

they are only problematic in pretest/postest designs

Which of the following is NOT a reason a researcher might choose to conduct a double-blind placebo control group study?

to prevent attrition

What are the two main reasons to conduct a factorial study?

to test limits and to test theories

Dr. Deveraux has conducted a study that has resulted in a null effect. Nonetheless, she suspects that there truly is a causal relationship between her independent and dependent variables. Which of the following is UNLIKELY to be to blame?

too many participants