PSY 2020 Exam 2
Dr. Jones is interested in studying how indoor lighting can influence people's moods during the winter. A sample of 100 households is selected. Fifty of the homes are randomly assigned to the bright-light condition where Dr. Jones replaces all the lights with 100-watt bulbs. In the other 50 houses, all the lights are changed to 60-watt bulbs. After two months, Dr. Jones measures the level of depression for the people living in the houses. In this example, how many dependent variables are there?
1
If a between-subjects experiment produces 50 scores in treatment 1 and 50 scores in treatment 2, then how many participants were in the entire experiment?
100
How many participants would be needed for a within-subjects experiment comparing four different treatment conditions with a total of 20 scores in each treatment?
20
A research study evaluates changes in behavior related to age by examining different groups of individuals with each group representing a different age. What is the name for this research design?
A cross-sectional developmental design
A research study evaluates changes in behavior related to age by examining one group of participants who are all roughly the same age, at different times. What is the name for this research design?
A longitudinal developmental design
What is the appropriate hypothesis test for a within-subjects design comparing mean differences for three treatment conditions?
A repeated-measures analysis of variance.
Which of the following is a general plan for implementing a research strategy?
A research design
Which of the following describes a completely counterbalanced within-subjects experiment?
A series of treatments is presented in every possible sequence.
Which of the following is an example of a nonexperimental study?
A study comparing self-esteem scores for children with a learning disability versus scores for children without a learning disability
Which of the following is an advantage of a two-treatment within-subjects design compared to a multiple-treatment design?
All of the above are advantages of a two-treatment design.
What is the appropriate statistical analysis for comparing non-numerical data for a differential design comparing samples representing two populations?
Chi-square test for independence
In order to establish an unambiguous relationship between two variables, it is necessary to eliminate the possible influence of which of the following variables?
Confounding variables
Which of the following is common in within-subjects experimental designs but is impossible in a pre-post design?
Counterbalance order of treatments
Cues given to participants about how they are expected to behave define which of the following terms?
Demand Characteristics
Which research design is used by a researcher comparing self-esteem scores for children from divorced families versus scores for children from families with no divorce?
Differential research design
Which statement best characterizes a between-subjects experimental design?
Each participant is assigned to one condition of the experiment.
Which of the following accurately defines diffusion?
Elements of the treatment in one group have spread to another group.
The degree to which your research results generalize beyond the specific characteristics of your study refers to
External Validity
Results from a research study suggest that a stop-smoking program is very successful. However, the participants who volunteered for the study were all highly motivated to quit smoking and the researcher is concerned that the same results may not be obtained for smokers who are not as motivated. What kind of validity is being questioned?
External validity
Which of the following describes a variable that exists in a study but is not being directly examined?
Extraneous
Which of the following is an option for limiting the variance within treatment conditions?
Hold a participant variable constant
What can a researcher determine by using a series of observations before treatment?
If scores are influenced by some factor unrelated to the treatment.
Which of the following maximizes the likelihood of a successful research result?
Increase the differences between treatments and decrease the variance within treatments
What is the appropriate statistical analysis for evaluating the after treatment mean difference for a posttest-only nonequivalent control group design?
Independent-measures t test
When comparing means in a two-group design, which statistical analysis is most appropriate?
Independent-measures t-test
Which of the following is the primary threat to internal validity for nonequivalent group designs?
Individual differences between treatment groups
For a between-subjects experiment, which of the following is a possible threat to internal validity?
Individual differences that exist between treatments
A researcher measures mood for a group of participants who have listened to happy music for 20 minutes and for a second group who have listened to sad music for 20 minutes. If different mood scores are obtained for the two groups, the researcher would like to conclude that music influences mood. However, the happy music group was tested in a room painted yellow and the sad music group was in a room painted dark brown and the researcher is concerned that the room color and not the music may influence mood scores. What kind of validity is being questioned?
Internal Validity
In a between-subjects experiment, if the participants in one group have characteristics that are different from the participants in another group, then which of the following is threatened?
Internal Validity
In a within-subjects research study comparing different treatment conditions at different times, what kind of validity is threatened by factors that change over time, such as history and maturation?
Internal validity
What aspect of a study is threatened if the participants are tested in one treatment condition at one time and then tested in a second treatment condition at a different time?
Internal validity
What is the effect of increasing the time between treatment conditions in a within-subjects experiment?
It decreases the threat of the order effect fatigue.
How does holding a variable constant prevent the variable from becoming a confound?
It eliminates the possibility that the variable will be substantially different from one group to another.
Which of the following is an advantage of the between-subjects design versus the within-subjects design?
It eliminates the risk of order effects.
In an experiment, what is the purpose for manipulating the independent variable?
It helps establish the direction of the relationship and it helps eliminate the third-variable problem.
A researcher exposes people to a stressful situation (such as public speaking) to examine the effect of stress on depressed mood. Why would the researcher also include a measure of stress?
It is a manipulation check.
Which of the following is the primary limitation of a two-group design?
It may not provide a complete picture of the relationship between the variables.
Which of the following characteristics are necessary for an extraneous variable to become a confounding variable?
It must change systematically when the independent variable is changed.
What is the purpose for using a control condition in an experiment?
It provides a baseline that can be used to evaluate the size of the treatment effect.
Which of the following is a potential problem with holding a participant variable constant?
It threatens the external validity of the study.
Although field studies tend to have higher external validity than traditional laboratory studies, what risk do they tend to have?
Lower internal validity
In an experiment comparing two treatments, the researcher assigns participants to treatment conditions so that each condition has fifteen 7-year-old children and ten 8-year-old children. For this study, what method is being used to control participant age?
Matching
Which of the following is a limitation of using matching rather than random assignment to form groups in a between-subjects experiment?
Matching requires another measurement procedure.
In a within-subjects study that extends over a relatively long time, it is possible that there will be systematic changes in the participants' skills or knowledge during the time of the study. If these changes influence the participants' scores, causing scores at the end of the study to be different from scores at the beginning, then what is the effect is called?
Maturation
Which of the following is the primary goal for randomly assigning participants to treatment conditions in an experiment?
Minimize the likelihood that a participant variable (such as age or gender) becomes a confounding variable
For which of the following studies does the researcher not control which individuals are assigned to which group?
Nonequivalent group design
A cross-sectional developmental design is an example of which general category of research designs?
Nonequivalent group designs
A research study attempts to describe the relationship between self-esteem and birth order position by measuring self-esteem for each individual in a group of first-born boys, and then comparing the results with self-esteem scores for a group of later-born boys. Which research strategy is being used?
Nonexperimental
Which of the following accurately defines compensatory equalization?
One group demands the same benefits received by another group.
Which of the following accurately defines compensatory rivalry?
One group works extra hard to make up for not receiving the benefits received by another group.
How do studies using the experimental research strategy differ from other types of research?
Only experiments can demonstrate a cause-and-effect relationship between variables.
Which of the following accurately describes the scores in a between-subjects experiment?
Only one score is obtained for each participant.
An experiment includes a treatment condition, a no-treatment control, and a placebo control. Which two conditions should be compared to determine the size of the effect that is actually caused by the treatment?
Placebo versus treatment
What design is being used by a researcher comparing depression scores before and after treatment in one group of clients?
Pre-post design
Which of the following does not guarantee that a specific participant variable will not become a confounding variable?
Randomizing the variable across treatment
For a within-subjects study comparing two treatments, A and B, a researcher expects that practice in the first treatment will improve the participants' scores in the second treatment. If the order of treatments is counterbalanced, then what scores will be influenced by the practice?
Scores in treatment A for half the participants and scores in treatment B for half the participants.
When comparing means in a single-factor multiple group design, which statistical analysis is most appropriate?
Single-factor ANOVA
A journal article reports that a new teaching strategy is very effective for first-grade students. A teacher wonders if the same strategy would be effective for a class of third-grade students. What is the teacher questioning?
The external validity of the report
What is measured and removed to reduce the variance in within-subjects design compared to a between-subjects design.
The individual differences
Which of the following is the primary advantage of a pretest-posttest nonequivalent control group design, in comparison to other nonequivalent group designs?
The pretest scores can help reduce the threat of individual differences between groups.
How can sensitization threaten external validity of a study?
The results may be limited to individuals who have experienced a pretest.
A clinical psychologist measures body satisfaction for a group of clients diagnosed with anorexia nervosa each day for 1 week before and for 1 week after the psychologist begins a series of group therapy sessions. What kind of design is being used?
Time-series
Which of the following questions can be addressed with the descriptive strategy?
What is the average number of text messages that a typical adolescent sends in a month?
For an experiment that compares two treatment conditions with ten scores in each treatment, which design would require fewer subjects?
Within-subjects design
A researcher moves an experiment out of the laboratory and into the real world. This type of research is called
a field study.
A study examining the relationship between humor and memory compares memory performance scores for one group presented with humorous sentences and a second group presented with nonhumorous sentences. The participants in one group are primarily 8-year-old students and those in the second group are primarily 10-year-old students. In this study, age is potentially a(n) ________ variable.
confounding
Experimental research studies tend to have very _______ internal validity but often have relatively _______ external validity.
high; low
Holding a variable constant is a technique for removing one threat to ________, but it can limit the ________ of an experiment.
internal validity, external validity
Researchers often use simulation experiments in an attempt to obtain the _________ of an experiment and still keep much of the _________ of research conducted in the real world.
internal validity, external validity
A nonexperimental design
makes no attempt to minimize threats to validity.
Research indicates the people who suffer from depression also tend to experience insomnia. However, it is unclear whether the depression causes insomnia or the lack of sleep causes depression. What problem is demonstrated by this example?
the directionality problem
