Q&A Hero

Q: A health psychologist conducts an experiment to test the effectiveness of four techniques for helping a person to relax. The psychologist has a limited number of people available to participate in the experiment and each relaxation technique takes some time to complete. The psychologist has decided, therefore, to use the incomplete repeated measures design with all possible orders to balance practice effects. What is the minimum number of participants the psychologist will need for this experiment? A. 4 B. 12 C. 24 D. 48

Q: When selected orders of conditions (Latin Square or random starting order with rotation) are used to balance practice effects in the incomplete repeated measures design, A. the number of selected orders must be exactly equal to the number of conditions in the experiment. B. the number of selected orders will always be equal to some multiple of the number of conditions in the experiment. C. the number of selected orders will always be equal to one less than the number of conditions in the experiment. D. there is no restriction on the number of possible orders needed to balance practice effects in the incomplete repeated measures design.

Q: Compared to random starting order with rotation, an advantage of the Latin Square technique for selecting orders in the incomplete repeated measures design is that in the Latin Square A. each condition is presented to each subject several times. B. practice effects are balanced within each individual. C. a random order of conditions is generated for each participant. D. each condition precedes and follows each other condition exactly once.

Q: The additional step needed when analyzing the results in a complete repeated measures design is to A. compute the mean (or median) score for each participant for each condition of the experiment. B. multiply participants' score in each condition by the order in which the condition appeared. C. add the participants' scores across all conditions and divide by the number of conditions. D. subtract the mean of all conditions from each participant's score.

Q: Repeated measures designs are more sensitive than random groups designs because the systematic variation due to individual differences is _________ the statistical analyses. A. eliminated from B. added to C. averaged into D. a critical part of

Q: The problem of _____ in a repeated measures design occurs when the effects of a condition persist or carryover to affect performance in the subsequent conditions. A. sensitivity B. anticipation effects C. differential transfer D. counterbalancing

Q: An incomplete repeated measures design experiment was done to test people's ability to solve problems that varied in difficulty at three levels (easy, moderate, and hard). The researcher used all possible orders to balance practice effects. Results indicated that performance on the hard problems was better when they were preceded by a moderate difficulty problem than when they were preceded by an easy problem. Which of the following is a possible explanation of this finding? A. anticipation effects B. nonlinear practice effects C. progressive error D. differential transfer

Q: A researcher designs an experiment with six conditions but each condition takes only a very short amount of time to administer. The researcher has the opportunity, therefore, to administer many trials of each condition in the experiment. Which of the following techniques is likely to be most effective for balancing practice effects? A. ABBA counterbalancing B. block randomization C. stratified randomization D. all possible orders of conditions

Q: An advantage of block randomization in the complete repeated measures design experiment is that A. each condition of the experiment is represented an equal number of times at all stages of practice. B. all trials of one condition are presented first, followed by all trials of a second condition, etc., making statistical computations easier. C. one condition is assigned to one "block" of participants, a second condition is assigned to a second block of participants, etc. D. stages of practice are randomly assigned to the different blocks of conditions.

Q: A student is considering doing a complete repeated measures design experiment involving motor skills. The student's advisor has told him that people show a large initial improvement on the task followed by slow steady improvement after this initial change. The student must choose a technique for balancing practice effects. Which technique should the student not use? A. ABBA counterbalancing B. block randomization C. Latin Square D. all possible orders

Q: When a participant in an experiment that involves the complete repeated measures design develops expectations about which condition should occur next in the sequence, the methodological problem that occurs is called A. reactivity effects. B. sequential effects. C. differential transfer. D. anticipation effects.

Q: In the incomplete repeated measures design, the levels of the independent variable for each participant are perfectly confounded with the A. characteristics of that particular participant. B. order in which the levels are presented. C. individual differences variables in the experiment. D. characteristics of the experimental task.

Q: Practice effects in the incomplete repeated measures design are balanced by A. ensuring first that the results for each participant are balanced across conditions. B. subtracting the results for the different groups of participants in the experiment. C. averaging across the results for all participants. D. first obtaining a summary score within each condition for each participant.

Q: Each of the three techniques that are used to balance practice effects in the incomplete repeated measures design conforms to a general rule that can be stated as A. each condition must appear in only one ordinal position. B. each condition must appear in the first ordinal position equally often. C. each condition must appear in each ordinal position at least twice. D. each condition must appear in each ordinal position equally often.

Q: (p. 223, 228-229) A researcher compares students' performance using a new learning strategy to their performance using the old strategy. Students' performance is first tested with the old strategy, followed by the new strategy. The results indicate that students perform better with the new strategy. These results A. show that the order of the two learning strategies does not matter. B. are uninterpretable due to the confounding with practice effects. C. indicate that teachers should use the new strategy. D. all of these

Q: Counterbalancing is an important research technique because it is used to A. average practice effects across conditions of a repeated measures design. B. average practice effects across conditions of an independent groups design. C. average individual differences variables across conditions of a repeated measures design. D. all of these

Q: Balancing the order of conditions in a repeated measures design A. equates practice effects with those found in random groups designs. B. eliminates practice effects in the conditions of the experiment. C. averages practice effects across the conditions of the experiment. D. balances individual differences variables across the conditions of the experiment.

Q: A marketing researcher wants to test the effectiveness of three different types of advertisement. Participants will respond to 50 examples of each type of advertisement so that the researcher can determine each person's preference. What type of design is this researcher using? A. conditional repeated measures design B. partial repeated measures design C. complete repeated measures design D. incomplete repeated measures design

Q: A researcher plans to conduct a complete repeated measures design in which the independent variable is manipulated using four conditions that vary the level of violence depicted in a photograph (none, low, medium, high). There are 10 photographs in each of the four conditions. Each participant will rate each photo once. If the researcher wishes to have 80 ratings for each photo, how many participants should the researcher recruit? A. 2 B. 10 C. 40 D. 80

Q: A psychologist wishes to have participants rate two different sets of inkblots (labeled A and B) for their "emotionality." The inkblots differ in their use of color. Ten inkblots in set A are created in shades of gray; ten inkblots in set B use shades of red, blue, and yellow. The psychologist hypothesizes that color will influence participants' ratings of emotionality. Each participant will rate all twenty inkblots. What potential confounding variable must be balanced in this research? Explain what balancing procedure would be best for this experiment.

Q: In an independent groups design, a separate group of people serves as a control group. In the repeated measures design, A. there is no control. B. participants serve as their own controls. C. all participants participate in one condition of the experiment. D. test-retest reliability is the main goal of the research.

Q: The need to balance practice effects in the repeated measures design is analogous to the need to balance ________ in the independent groups design. A. order effects B. reactivity C. individual differences D. subject loss

Q: Which of the following is not one of the reasons researchers choose to use the repeated measures design? A. Repeated measures designs are generally less sensitive than are independent groups designs. B. Repeated measures designs are more convenient and efficient. C. Repeated measures designs require fewer subjects. D. Repeated measures designs are needed when the experimental procedures require participants to compare two or more stimuli.

Q: A sensitive experiment refers to the ability to detect the effect of the independent variable even if the effect is _________. A. uneven B. small C. large D. very large

Q: In general, participants in a repeated measures design will vary within themselves less over conditions of the experiment than participants in a random groups design will vary from other participants across conditions. This means there is likely to be ________ in repeated measures designs compared to random groups designs. A. less error variation B. less sensitivity C. more bias D. more individual differences

Q: The difference between repeated measurements to establish test-retest reliability and experiments using repeated measures designs is that in experiments with repeated measures designs A. the reliability of measurement is not important. B. a correlation coefficient would be used to determine consistency across measurements. C. measurements occur only twice. D. measurements are compared for different conditions of an independent variable.

Q: There can be no confounding by individual differences variables in the repeated measures designs because A. intact groups of participants are assigned to the different conditions of the experiment. B. individual differences variables are held constant. C. the same participants are tested in all conditions. D. participants are tested in only one condition of the experiment.

Q: When using a repeated measures design, researchers must control the potential threat to internal validity referred to as A. individual differences variables. B. sensitivity. C. incomplete orders. D. practice effects.

Q: Define differential transfer and describe one method a researcher could use to detect whether differential transfer is a problem in a repeated measures experiment.

Q: (p. 220, 222-224) Identify the differences between the random groups design and the repeated measures design in terms of how the independent variable is manipulated and what potential confounding variable must be balanced in each design. What method(s) are available for balancing in each design?

Q: Explain why ABBA counterbalancing would be ineffective in balancing practice effects in the complete repeated measures design when the practice effects involve an abrupt initial change followed by little change thereafter.

Q: What are one advantage and one disadvantage of using all possible orders to balance practice effects in the incomplete repeated measures design?

Q: Researchers found a relationship between insults and aggressive behavior for 5-year olds. If they want to test the external validity of the conceptual relationship between insults and aggressive behavior for a sample of 35-year olds, they should A. test the findings in the real world rather than in a laboratory setting. B. use the same measure of aggression as was used with the 5-year olds. C. use age-appropriate insults and measures of aggression for the 35-year olds. D. use the same insults as was used with the 5-year olds.

Q: A cognitive psychologist wants to do an experiment to test a variable that may influence the memory of elderly people. She has the following constraints: only 12 people are available as possible participants, and the independent variable she plans to manipulate requires the use of a separate group for each of the two conditions. The psychologist has a reliable and valid pretest she can use to evaluate participants' memory prior to the manipulation. Which design is this psychologist likely to use? A. random groups design B. natural groups design C. matched groups design D. placebo control design

Q: When conducting an experiment using the matched groups design, the preferred matching variable is A. completely different from the dependent variable. B. an inexpensive test that participants could complete quickly. C. a measure with limited reliability and validity. D. the same measure that will be used as the dependent variable.

Q: Which of the following conditions would lead you to recommend against the use of a matched groups design and in favor of a random groups design? A. a small number of participants from a heterogeneous population is available B. a large number of participants from a homogeneous population is available C. a separate group is required for each level of the independent variable of interest D. a reliable and valid matching variable is available

Q: A researcher plans to use a matched groups design to assess a treatment for increasing body weight of premature infants. The independent variable has two conditions, treatment and control. Eight pairs of premature infants are matched according to their body weight prior to manipulating the independent variable. In order to control for other potentially relevant characteristics of the participants, the researcher should A. identify a matching variable uncorrelated with body weight. B. assign the lower weight infant in each pair to the treatment condition. C. randomly assign infants in each pair to the treatment or control group. D. none of these

Q: Which of the following is an example of an individual differences (subject) variable? A. individuals randomly assigned to one of three different treatments in a diabetes study B. an independent variable involving three levels of nicotine in a smoking cessation program C. a law enforcement training program compared over a 4-week or an 8-week period D. individuals classified as introverted or extraverted in a study of alcohol use

Q: To differentiate experiments involving individual differences (subject) variables and those involving manipulated independent variables, those experiments involving groups selected based on individual differences (subject) variables are called A. selected subjects designs. B. matched groups designs. C. random groups designs. D. natural groups designs.

Q: The natural groups design represents an illustration of the general research approach that is called A. correlational research. B. descriptive research. C. experimental research. D. observational research.

Q: Which of the following is the most critical problem in drawing causal inferences based on the natural groups design? A. establishing covariation B. correlating participants' characteristics and their performance C. eliminating plausible alternative causes for the obtained relationship D. using the natural groups variable to make predictions for the dependent variable

Q: Cite two reasons why a researcher might choose to use a repeated measures design.

Q: Provide brief answers to the following question regarding the repeated measures designs. What distinguishes the complete repeated measures design from the incomplete repeated measures design?

Q: (p. 224-227, 230-232) Provide brief answers to the following question regarding the repeated measures designs. What techniques are used in the complete and incomplete repeated measures designs to balance practice effects?

Q: In what situation is it argued that external validity is irrelevant? A. when psychologists seek to describe real-world settings based on laboratory research. B. when research is conducted with college student samples. C. when the goal of an experiment is to observe the most typical case found in nature. D. when the purpose of the experiment is to test a specific hypothesis derived from a theory.

Q: A researcher read a research report indicating that a certain medication was found to be effective when tested on men. The researcher plans to do an experiment testing the effectiveness of the same medication, but in his experiment both men and women will be tested. The researcher is planning to do a A. partial replication of the experiment to test the reliability and external validity of the finding from the original experiment. B. replication of the experiment to test the internal validity of the original experiment. C. replication of the experiment to test the sensitivity of the original experiment. D. partial replication of the experiment to test the statistical power of the original experiment.

Q: The problem of Type I and Type II errors occurs because A. decision making based on inferential statistics depends on probabilities. B. researchers rarely conduct internally valid experiments. C. the null hypothesis is difficult to define. D. all of these

Q: A Type I error occurs when the null hypothesis is really true and we claim A. the independent variable did not have an effect on behavior. B. the independent variable did have an effect on behavior. C. the inferential test was not statistically significant. D. that the results are not statistically significant.

Q: When we conclude that an experiment does not provide sufficient evidence to reject the null hypothesis when, in fact, an independent variable does produce an effect, the inferential statistics problem is called a A. Type I error. B. Type II error. C. no-confidence interval. D. probability error.

Q: (p. 181, 205) ________ refers to the researcher's ability to make causal inferences regarding an experimental outcome and _________ refers to the researcher's ability to generalize the findings beyond the scope of the specific experiment. A. Reliability; validity B. Replication; confounding C. Internal validity; external validity D. External validity; internal validity

Q: When the findings of experiments testing the effectiveness and safety of drugs on animals are replicated in clinical trials with people, the original findings of the animal research are shown to have A. external validity. B. internal validity. C. statistical significance. D. sensitivity.

Q: A researcher conducted an experiment in which participants played either a violent or a nonviolent video game. After the game, the researcher measured hostile cognitions. The effect size, Cohen's d, for the difference in mean hostile cognition between the violent and nonviolent conditions was .83. Based on this, it is possible to state that the video game independent variable had a _______ effect on hostile cognition in this experiment. A. nonsignificant B. small C. medium D. large

Q: Which of the following is not an advantage of using measures of effect size? A. Measures of effect size provide information about the strength of the relationship between an independent variable and a dependent variable. B. Measures of effect size provide the best information about whether the effect of the independent variable is statistically significant. C. Measures of effect size can provide an estimate of the overall effect size for an independent variable by averaging effect sizes across a series of experiments. D. Measures of effect size can be used to make quantitative comparisons of the different outcomes found in a series of experiments involving the same independent variable.

Q: The statistical technique that is used to analyze the results of several independent experiments is called A. F-test. B. central tendency. C. meta-analysis. D. Cohen's d analysis.

Q: Two statistical methods that researchers use to determine whether an independent variable has a reliable effect on a dependent variable are A. null hypothesis significance testing and confidence intervals. B. statistical significance and odds-likelihood analysis. C. analysis of error variation and effect size. D. Cohen's d and alpha.

Q: The nonsystematic (random) variation due to differences among subjects within each group is called A. spurious variation. B. nonsignificant variation. C. inferential variation. D. error variation.

Q: A statistically significant outcome is an outcome that A. leads us to reject the null hypothesis. B. assures the internal validity of the experiment. C. assures that practical applications of the outcome will be successful. D. all of these

Q: A statistically significant outcome is an outcome that A. has a large likelihood of occurring if the null hypothesis is true. B. has a small likelihood of occurring if the null hypothesis is true. C. always has a large effect size. D. has neither Type I nor Type II errors.

Q: A researcher computes an inferential statistic to test the difference between mean scores for an experimental group and a control group. The probability of the obtained statistical value for the t-test is .025, which is less than the alpha level of significance (p < .05). The researcher should A. reduce the alpha level of significance to .025 to form a definite conclusion. B. accept the null hypothesis of no difference between the experimental and control groups because the probability is so small; thus, the independent variable had no effect. C. reject the null hypothesis of no difference between the experimental and control groups because the probability is so small; thus, the independent variable had a reliable effect on the dependent variable. D. neither accept nor reject the null hypothesis of no difference because the probability value of .025 is significantly different than .05.

Q: We can be confident that the population means differ for two conditions of an experiment when the confidence intervals for the two sample means A. are of different size. B. have different standard deviations. C. overlap. D. do not overlap.

Q: A researcher computes a .95 confidence interval for an experimental group to be 3.0 B 7.0, and computes a .95 confidence interval for a control group to be 0.0 B 4.0. Based on these confidence intervals, the researcher can state that A. the results for the effect of the independent variable on the dependent variable are inconclusive. B. the independent variable definitely influenced participants' scores on the dependent variable because the confidence interval for the experimental group is higher than that that of the control group. C. the independent variable definitely did not affect participants' scores because the confidence interval for the control group includes zero. D. the population value for the experimental group is .95.

Q: Our ability to draw appropriate conclusions based on the results of an experiment depends most of all on the A. external validity of the experiment. B. internal validity of the findings. C. amount of variation in the experiment. D. statistical significance of the findings.

Q: Which of the following is a measure of the strength of the relationship between the independent and dependent variables that is independent of sample size? A. t-test B. standard deviation C. mean difference score D. effect size

Q: If participants know they have been given alcohol in an experiment, they may expect certain effects such as giddiness or relaxation. The general term for such cues that guide participants' behavior in a study is A. double-blind effects. B. self-inflicted characteristics. C. expectation effects. D. demand characteristics.

Q: When observers have biases regarding what they expect participants' behavior to be like in an experiment, the observations may be influenced by A. placebos. B. demand characteristics. C. experimenter effects. D. selective subject loss.

Q: Placebo control groups and double-blind procedures are typically used to control for A. individual differences variables and matching variables. B. demand characteristics and experimenter effects. C. selective subject loss and mechanical subject loss. D. manipulated variables and extraneous variables.

Q: Which of the following is the best way to determine whether the differences in means obtained in an experiment are reliable? A. Replicate the experiment. B. Use confidence intervals to compare the means. C. Perform an inferential statistics test (null hypothesis significance testing). D. Find the difference between two sample means.

Q: The three steps of data analysis are A. find any outliers, compute confidence intervals, and do null hypothesis significance testing. B. check the data, summarize the data, and confirm what the data reveal. C. find Type I and Type II errors, compute means, and compute inferential statistics. D. calculate the standard deviation, find the effect size, and do null hypothesis significance testing.

Q: After checking the data for errors and outliers, the next step in analyzing the data from a research study is to use A. confidence intervals. B. meta-analysis. C. descriptive statistics. D. inferential statistics and null hypothesis significance testing.

Q: The procedure for using block randomization in an independent groups experiment with three conditions (A, B, C) and 60 subjects is to generate twenty random orders of the conditions (e.g., ACB, BAC) and assign subjects one block at a time (i.e., 3 subjects in the first block, 3 in the second block, and so on). B. generate one random order of conditions (e.g., ACB) and test the first 20 subjects in condition A, the second 20 subjects in condition C, and the last 20 subjects in condition B. C. select intact groups of 20 subjects each and randomly assign the groups to condition A, B, or C. D. generate sixty random orders of the conditions, one for each subject.

Q: In addition to creating groups of equal size, an advantage of block randomization is that it A. decreases the number of participants needed in each condition. B. averages the effect of the dependent variable across the conditions of the experiment. C. holds constant the time in which an experiment is run. D. balances potential confoundings that occur during the time in which an experiment is run.

Q: A researcher randomly assigns one classroom to a new teaching method and a second classroom to the control condition (the regular teaching method). This researcher faces the potential problem of confounding due to A. experimenter effects. B. selective subject loss. C. intact groups. D. extraneous variables.

Q: An instructor randomly assigns two sections of his course to an experimental condition (new teaching method) or control condition (regular teaching method). Students in the 9:30 section receive the experimental treatment and students in the 1:30 section participate in the control condition. At the end of the semester the instructor's tests reveal that students in the 9:30 section had significantly higher test scores than students in the 1:30 section. Based on this summary, we can state that A. the results are uninterpretable because of intact groups. B. the findings have external validity across two times of day. C. the experiment has internal validity. D. all of these

Q: In order to conduct an experiment more efficiently, a researcher tests groups of participants in several small groups. The number of participants in each group differs because of participants' availability at different times. The different number of participants in each group represents a potential A. intact group problem. B. selective subject loss problem. C. experimenter effect. D. extraneous variable problem.

Q: Four students plan to conduct an experiment with four conditions (A, B, C, and D) during one semester. Each student will serve as an experimenter. The best way to control for the extraneous variable of having four experimenters test participants in the study is to A. make sure each experimenter tests only one of the conditions. B. have the first experimenter test a random order of conditions during the first two weeks of the semester, the second experimenter test a second random order during the next two weeks, and so on. C. have each experimenter test randomized blocks of conditions. D. have each experimenter test condition A during the first two weeks of the semester, condition B during the next two weeks, and so on.

Q: When participants begin an experiment but fail to complete it, the internal validity of the experiment can be threatened. Which of the following types of subject loss poses the most serious threat to internal validity? A. the loss occurs because of an error by the experimenter. B. the loss leads to different numbers of participants in the groups in the experiment. C. the loss occurs because of equipment failure. D. the loss occurs because of some characteristic of the participant that is related to the outcome of the study.

Q: Subject loss (attrition) poses a problem for a random groups design because A. extraneous variables are more likely to affect subjects who drop out. B. group equivalence established at the beginning of the experiment may be lost. C. participants may respond to demand characteristics. D. participants may change their natural group designation.

Q: One preventive step researchers can take when they suspect selective subject loss might occur in their experiment involves using a pretest to screen out participants who may drop out of the study. The disadvantage of this method is decreased A. external validity. B. internal validity. C. statistical significance. D. all of these

Q: The most common solution to the problem of forming comparable groups in the random groups design is A. random-digit dialing. B. random assignment. C. random selection. D. matching participants on the dependent variable.

Q: Which of the following arises when the independent variable of interest and an unintended independent variable are allowed to covary? A. contamination effect B. decrease in external validity C. illusory correlation D. confounding