Experimental Psychology chapter 9-11

b. bar; histogram

292. To graph a qualitative variable, use a ________ graph, and to graph a quantitative variable, use a ___________ graph. a. pie; bar b. bar; histogram c. histogram; bar d. line; bar

a. it only uses the extreme scores and so does not tell us how variable the scores are between those extreme scores.

303. One limitation of the range is that a. it only uses the extreme scores and so does not tell us how variable the scores are between those extreme scores. b. it can only be calculated when the variable is measured on a nominal scale of measurement. c. calculation of the range increases our risk of a Type I error. d. calculation of the range increases our risk of a Type II error.

b. The scores tend to be spread out.

304. What does a large number for variance mean? a. The scores tend to be clustered together. b. The scores tend to be spread out. c. The distribution must be bimodal. d. The distribution must be normal.

d. square root of variance

305. What is the formula for standard deviation? a. ΣX/N b. (variance)2 c. variance x 2 d. square root of variance

d. normal distribution.

306. A symmetrical, bell-shaped curve is known as a a. bimodal distribution. b. positively skewed distribution. c. negatively skewed distribution. d. normal distribution.

d. 95%

311. Approximately _____ of all scores in a normal distribution occur between 2 SDs below the mean and 2 SDs above the mean. a. 13% b. 34% c. 68% d. 95%

c. 55

320. There is a perfect positive correlation in the data below. X Y 25 40 26 43 27 46 28 49 29 52 If someone scores a 30 on the X variable, what should we predict the Y value to be? a. 30 b. 52 c. 55 d. Cannot be determined from the information given.

a. Descriptive; inferential

242. ___________ statistics summarize numbers and _____________ statistics determine whether the results are significant.

c. a measure of central tendency.

243. Ethan wants to determine the representative score in his distribution. Ethan will need to calculate a. variability. b. inferential statistics. c. a measure of central tendency. d. the range.

d. measurement.

244. The assignment of symbols to events according to a set of rules is known as a. statistics. b. a Type I error. c. a Type II error. d. measurement

b. interval

253. Temperature in Fahrenheit represents a(n) __________ scale of measurement. a. ordinal b. interval c. ratio d. nominal

b. ratio

256. The presence of a true zero point is characteristic of the ________ scale of measurement. a. nominal b. ratio c. interval d. ordinal

d. All of the above.

258. Which of the following is a property of the ratio scale of measurement? a. True zero point b. Equal intervals between scores c. Scores are rank ordered d. All of the above.

c. ratio

259. "Rachel made half as many mistakes as Erin." This statement represents a(n) __________ level of measurement. a. ordinal b. interval c. ratio d. nominal

c. Nominal

260. Which scale of measurement provides the least amount of information? a. Ratio b. Interval c. Nominal d. Ordinal

a. Ratio

261. Which scale of measurement provides the greatest amount of information? a. Ratio b. Interval c. Nominal d. Ordinal

c. mode.

262. The most frequently occurring score in a distribution is the a. median. b. mean. c. mode. d. range

a. 3

263. Consider the following scores: 1, 2, 3, 3, 11. What is the mode? a. 3 b. 4 c. 11 d. 20

a. 2

269. Consider the following scores: 1, 1, 2, 2, 3, 3, 3. What is the median? a. 2 b. 3 c. 2.14 d. 15

c. ordinal, interval, or ratio data.

270. The median can be calculated for a. nominal data only. b. interval or ratio data. c. ordinal, interval, or ratio data. d. nominal, ordinal, interval, or ratio data.

b. median.

271. Darnell would like to calculate a measure of central tendency for his rank-ordered data. Darnell should use the a. mean. b. median. c. mode. d. Central tendency cannot be calculated for this data.

b. mean

272. The __________ is the arithmetic average. a. mode b. mean c. median d. standard deviation

b. Add up all the scores.

274. What does ΣX mean? a. Add up all the scores and divide by the sample size. b. Add up all the scores. c. Divide by the sample size. d. Multiple the scores together

c. 20

275. Consider the following scores: 2, 3, 4, 11. What is ΣX? a. 3.5 b. 4 c. 20 d. ΣX cannot be calculated for these scores.

b. ΣX/N

276. What is the formula for calculating the mean? a. ΣX - N b. ΣX/N c. N/ΣX d. N - ΣX

b. Median

279. Consider the following ratio-level scores: 1, 2, 3, 4, 24. What is the best choice for central tendency? a. Mode b. Median c. Mean d. Variance

a. Mean

280. Which measure of central tendency takes into account the value of every number in the distribution? a. Mean b. Mode c. Median d. Variance

a. small

348. Eileen calculates an effect size of d = .45 for her study. According to Cohen (1977), this is considered a(n) ________ effect size. a. small b. medium c. large d. extra-large

b. t test.

Nora would like to conduct an experiment to determine whether behavior modification techniques can help children eliminate bedwetting. She obtains a sample of children who wet the bed and randomly assigns half to the behavior modification therapy and half to a control group who receive no therapy. After six months, she measures how often children in each group wet the bed. 329. In order to determine whether the therapy group is significantly different from the control group, Nora will have to conduct a a. two-factor ANOVA. b. t test. c. z test. d. correlational test.

b. Mean

281. Which measure of central tendency is favored by most psychologists? a. Median b. Mean c. Mode d. Variance

.c. statistics

241. The branch of mathematics that involves the collection, analysis, and interpretation of data is referred to as a. algebra. b. calculus. c. statistics. d. geometry.

d. Variable

246. Which of the following is NOT one of the four scales of measurement? a. Ratio b. Interval c. Ordinal d. Variable

b. β

341. The symbol for a Type II error is: a. α b. β c. Σ d. Φ

d. decrease; increase

342. By changing the significance level from .05 to .01, you _______ the chance for a Type I error and ________ the chance for a Type II error. a. increase; increase b. decrease; decrease c. increase; decrease d. decrease; increase

a. Type I; Type II

343. ________ errors are under the direct control of the experimenter, and _______ errors are not under the direct control of the experimenter. a. Type I; Type II b. Type II; Type I c. Type II; hypothesis d. Type I; hypothesis

b. Increase the sample size.

344. Which of the following can help minimize Type II errors? a. Decrease the sample size. b. Increase the sample size. c. Use one dependent variable instead of several. d. Use convenience sampling instead of random sampling.

d. Effect size

345. ________ is a statistical measure that conveys information about the magnitude of the effect produced by the independent variable. a. A t test b. Pearson's product-moment correlation coefficient c. Standard deviation d. Effect size

a. A significant statistical test tells us that the IV had an effect, and the effect size tells us about the size of the significant effect.

346. If our statistical result was significant, what is the value of calculating effect size? a. A significant statistical test tells us that the IV had an effect, and the effect size tells us about the size of the significant effect. b. Effect size tells us that the IV had an effect, and a significant statistical test tells us about the size of the significant effect. c. Effect size tells us if we need to change our test from a one-tailed test to a two-tailed test. d. If the statistical result was significant, you do not need to calculate effect size (the information is redundant).

c. d = .70

347. Which of the following would be considered a medium effect size? a. d = .20 b. d = .40 c. d = .70 d. d = .80

c. How many independent variables will my experiment have?

349. Which of the following is the FIRST question researchers should ask themselves when considering any experimental design? a. How many groups (levels) will my independent variable have? b. What type of participant groups do I have (independent or correlated)? c. How many independent variables will my experiment have? d. How many confounds should I include?

b. type of therapy; four

350. Miguel conducts a study in which he compares the effectiveness of behavioral therapy, cognitive therapy, humanistic therapy, and psychodynamic therapy to treat phobias. In this study, the independent variable is _________ and it has ____ level(s). a. type of therapy; one b. type of therapy; four c. effectiveness of therapy; one d. effectiveness of therapy; four

c. principle of parsimony.

351. The belief that explanations of phenomena should remain simple until the simple explanations are no longer valid is known as the a. error variability. b. asymptotic principle. c. principle of parsimony. d. placebo principle

a. How many levels of the IV will I use?

352. Suppose you know you would like to conduct a one-IV experiment. What is the second question that you need to answer? a. How many levels of the IV will I use? b. Will I conduct an experiment or a correlational study? c. Will I conduct a confounded experiment or a true experiment? d. All of the above

d. three or more

353. A multiple-group design compares _________ level(s) of the independent variable. a. one b. two c. one or two d. three or more

b. treatment

354. Participants who receive the IV are referred to as the _________ group. a. control b. treatment c. confound d. random

c. Cathy's results supported the hypothesis.

355. Cathy examined the effect of different teaching methods on students' exam performance. She randomly assigned college students to listen to one of three lectures and then tested them over the material. As hypothesized, she found that students taught by Method 1 earned significantly higher exam grades than students taught by Method 2 or Method 3. Which of the following is the best conclusion to draw from these results? a. Because Cathy has not done an experiment, she should not draw any cause-and-effect conclusions. b. Cathy has proven that Method 1 is superior to Method 2 and Method 3. c. Cathy's results supported the hypothesis. d. Cathy's study has high external validity.

b. independent

356. Groups of participants that are formed by random assignment are known as _________ groups. a. correlated b. independent c. matched pairs d. natural pairs

c. correlated

357. Groups of participants that are related in some way are known as _________ groups. a. random b. independent c. correlated d. confounded

b. random

358. If each participant in an experiment has an equal chance of being in any of the groups, then the researcher has used __________ assignment. a. correlated b. random c. nonrandom d. ex post facto

a. the groups should be equalized on potential extraneous variables.

359. If a researcher has used random assignment, then a. the groups should be equalized on potential extraneous variables. b. participants are matched on characteristics thought to be important for the dependent variable. c. participants experience the dependent variable two or more times. d. everyone in the population has an equal chance of being included in the experiment.

d. Convenience sampling

360. Which of the following is NOT a control procedure? a. Random assignment b. Matching c. Natural sets d. Convenience sampling

c. confounded

361. An experiment in which an extraneous variable varies systematically with the IV is a(n) ________ experiment. a. ex post facto b. correlated-groups c. confounded d. true

b. She has confounded gender and type of television program

362. Latitia conducted an experiment in which all the men watched an aggressive television program, and all the women watched a non-aggressive television program. Her results showed that people who watched the aggressive program were later more aggressive than people who watched the non-aggressive program. She concludes that aggressive television programming is detrimental. What is the biggest problem in Latitia's experiment? a. She has not used random selection procedures. b. She has confounded gender and type of television program. c. She should have used a correlated-groups design instead of an independent-groups design. d. None of the above; there are no problems in Latitia's experiment.

d. All of the above.

363. Researchers often choose a correlated-groups design over an independent-groups design when a. their sample size is small. b. they expect small differences owing to their IV. c. they want to reduce error variance. d. All of the above.

c. matched

364. Researchers form ________ sets by measuring participants on some variable that will affect their performance on the DV. a. random b. independent c. matched d. natural

d. matched

365. Larry conducts an experiment with three groups: (1) writing about traumatic events, (2) writing about happy events, and (3) writing about neutral events. Larry then measures the number of visits each participant makes to the health center over the next six months. Larry gives the participants a pretest regarding their health visits prior to the study so that he can create sets of participants who are equivalent on that variable. Participants are randomly assigned to condition from each set. Larry has used _________ sets. a. natural b. independent c. repeated measures d. matched

b. We decrease our chances of finding a significant effect.

366. What happens when we match participants on a variable that is unrelated to the dependent variable? a. We increase our chances of finding a significant effect. b. We decrease our chances of finding a significant effect. c. We increase the generalizability of our experiment. d. We decrease our chances of having experimenter bias in the study.

c. repeated measures

367. When you use _________, each participant must take place in all the various treatment conditions. a. matched sets b. natural sets c. repeated measures d. random assignment

d. Repeated measures

368. Darryl conducts a study in which participants rate their liking for their professor on the first day of class, at midterm, and on the last day of class. Darryl has used which research design? a. Matched sets b. Natural sets c. Independent groups d. Repeated measures

c. natural

369. Lisa is conducting a study using sets of siblings. She assigns each sibling from a family into a different group. Lisa is using _____ sets. a. repeated b. matched c. natural d. independent

d. Random assignment

370. Which of the following is NOT a way to create correlated groups? a. Repeated measures b. Matched sets c. Natural sets d. Random assignment

c. You add another level to an independent variable.

371. In what way is a two-group design different from a multiple-group design? a. You add another independent variable. b. You add another dependent variable. c. You add another level to an independent variable. d. You add another level to a dependent variable.

a. Will participants become bored or fatigued over time?

372. Suppose you were interested in conducting a repeated measures experiment with 15 levels. Which of the following might be your greatest concern? a. Will participants become bored or fatigued over time? b. Will I be able to secure enough participants for that many groups? c. Will I be able to find significant effects given that I am using so few groups? d. Will the groups be equivalent before the study begins?

c. Decreasing; increase

373. __________ error variability will __________ your likelihood of finding a significant effect. a. Increasing; not affect b. Decreasing; decrease c. Decreasing; increase d. Decreasing; not affect.

b. Correlated groups; independent groups

374. ___________ designs have decreased error variability compared to __________ designs. a. Independent groups; correlated groups b. Correlated groups; independent groups c. Natural sets; correlated groups d. Repeated measures; matched sets

c. Natural sets that are large enough may be difficult to obtain.

375. What is one limitation of using natural sets in a multiple-group design? a. The probability of finding a significant result is lower compared to when you use independent groups. b. There is not as much control in the experiment compared to an independent-groups design. c. Natural sets that are large enough may be difficult to obtain. d. There is an increased risk of experimenter bias with natural sets.

a. You will need a large number of participants to fill the multiple groups.

376. Which of the following is a practical consideration in a multiple-independent-groups design? a. You will need a large number of participants to fill the multiple groups. b. You will need a large number of participants to conduct proper matching of a variable of interest. c. You will need to guard against participants becoming bored or fatigued over many administrations of the dependent variable. d. All of the above.

d. a placebo effect.

377. An experimental effect caused by expectation or suggestion rather than the IV is known as a. a parsimonious effect. b. error variability. c. randomization. d. a placebo effect.

c. independent groups; placebo

378. Melinda conducts a study in which some participants receive an antidepressant, others receive a sugar pill that they think is an antidepressant, and the rest receive nothing at all. She finds that both the antidepressant group and the sugar pill group report being less depressed than the control group. Melinda has conducted a(n) _____________ study and the results for the sugar pill group are likely due to a ____________ effect. a. repeated measures; placebo b. repeated measures; sugar c. independent groups; placebo d. independent groups; sugar

a. ex post facto

379. Research conducted with a measured rather than manipulated independent variable is referred to as __________ research. a. ex post facto b. repeated measures c. correlated groups d. independent groups

c. ex post facto

380. Nina obtains a sample of people who are classified as low, medium, and high in generalized anxiety. She then measures their persistence on a difficult laboratory task. Nina's research would best be classified as __________ research. a. repeated measures b. correlated groups c. ex post facto d. true experiment

c. one-way ANOVA.

381. A statistical test used to analyze data from an experiment with one independent variable that has three or more groups is known as a a. two-factor ANOVA. b. t-test. c. one-way ANOVA. d. z-test.

a. one-way ANOVA

382. Rich has conducted a study in which he compares the reading skills of 6-year-olds, 7-year-olds, and 8-year-olds. What kind of statistical test should Rich use? a. one-way ANOVA b. t-test c. three-way ANOVA d. Pearson product-moment correlation coefficient

c. completely randomized

383. When you assign your participants to multiple groups randomly, you analyze your data using a _____________ ANOVA. a. repeated-measures b. correlated-groups c. completely randomized d. within-subjects

b. repeated-measures ANOVA

384. What kind of statistical analysis would you conduct if you used multiple groups and correlated groups of participants? a. repeated-measures t-test b. repeated-measures ANOVA c. completely randomized ANOVA d. independent samples t test

c. true experiment; completely randomized ANOVA

385. Courtney conducts a study in which she randomly assigns some rats to receive a high dose of alcohol, other rats to receive a low dose of alcohol, and a final group receives no alcohol. She measures the time it takes them to learn a new maze. Courtney's study represents a(n) __________ and her statistical technique for analyzing the data should be a ___________. a. ex post facto design; repeated-measures ANOVA b. ex post facto design; completely randomized ANOVA c. true experiment; completely randomized ANOVA d. true experiment; repeated-measures ANOVA

c. repeated-measures ANOVA

386. Daisy conducts a study in which a sample of rats receives a high dose of alcohol on one day, a low dose of alcohol on one day, and no alcohol on one day. Each day, she measures the time it takes them to learn a new maze. What statistical technique should Daisy use to analyze her data? a. completely randomized ANOVA b. repeated-measures t test c. repeated-measures ANOVA d. repeated-measures three-factor ANOVA

b. operational definitions

387. What kind of definitions do researchers use when planning their experiments? a. dictionary definitions b. operational definitions c. ANOVA definitions d. summarized definitions

a. Between; within

388. ________-groups variability represents the variation in the DV that is due to the IV, and ________-groups variability represents the variation in the DV that is due to such factors as individual differences and errors in measurement. a. Between; within b. Within; error c. Error; within d. Within; between

d. between-groups

389. The differences among the groups in a multiple-group experiment represent _____________ variability. a. within-groups b. randomized c. controlled d. between-groups

a. within-groups

390. Individual differences among people in each group in a multiple-group experiment represent _________ variability. a. within-groups b. randomized c. controlled d. between-groups

a. between-groups variability / within-groups variability

391. The ANOVA formula is best conceptualized as: a. between-groups variability / within-groups variability b. within-groups variability / between-groups variability c. (within-groups variability + between-groups variability) / between-groups variability d. (within-groups variability - between-groups variability) / within-groups variability

c. much larger than one.

392. If our IV has a strong effect, then the F value should be a. close to zero. b. close to one. c. much larger than one. d. negative

c. large; significant

393. If the between-groups variability is much larger than the within-groups variability, then the F value should be ______ and our results will be __________. a. small; significant b. small; nonsignificant c. large; significant d. large; nonsignificant

b. source

394. A table that contains the results of an ANOVA is referred to as a(n) _________ table. a. sum of squares b. source c. statistics d. F-ratio

a. sum of the squared deviations around the mean.

395. Sum of squares refers to the a. sum of the squared deviations around the mean. b. between-groups variability squared. c. within-groups variability squared. d. sum of the squared means

d. Not enough information is provided to assess significance.

396. Suppose you conduct a one-way ANOVA and obtain the following means: M = 8.78 for Group 1, M = 6.55 for Group 2, and M = 4.22 for Group 3. Which of the following conclusions is correct? a. Group 1 scored significantly higher than Group 2 or Group 3. b. All three means are significantly different from each other. c. Group 3 scored significantly lower than Group 1 or Group 2. d. Not enough information is provided to assess significance.

c. dividing each source's sum of squares by its degrees of freedom.

397. Mean squares are computed by a. squaring each source's sum of squares and dividing by its degrees of freedom. b. squaring each source's degrees of freedom and dividing by its sum of squares. c. dividing each source's sum of squares by its degrees of freedom. d. dividing each source's degrees of freedom by its sum of squares.

a. Number of participants - number of groups

398. What is the formula for within-groups degrees of freedom? a. Number of participants - number of groups b. Number of groups - number of participants c. Number of groups - 1 d. Number of participants - 1

c. Number of groups - 1

399. What is the formula for between-groups degrees of freedom? a. Number of participants - number of groups b. Number of groups - number of participants c. Number of groups - 1 d. Number of participants - 1

b. variance.

400. A mean square is similar to a. the range. b. variance. c. the mode. d. the median.

b. Mean square between groups / mean square within groups

401. What is the formula for the F ratio? a. Mean square within groups / mean square between groups b. Mean square between groups / mean square within groups c. Mean square between groups / df between groups d. Mean square within groups / df within groups

b. between; within

402. If you obtain an F ratio of 5, this means that the __________-groups variability is five times larger than the __________-groups variability. a. within; between b. between; within c. within; mean square d. mean square; between

a. less than .05.

403. A significant effect in an ANOVA occurs when the probability value is a. less than .05. b. greater than .05 c. less than .50. d. greater than .50

a. 3.38

404. Suppose we conduct a study in which the between-groups df was 2 and the within-groups df was 25. According to the F table, what value does our F ratio have to be in order for our ANOVA to be significant at the .05 level? a. 3.38 b. 5.57 c. 19.45 d. 99.46

c. significant ANOVA to determine which groups differ significantly from each other.

405. Post-hoc comparisons are conducted after a a. significant ANOVA to determine whether the between-groups variability exceeded the within-groups variability. b. nonsignificant ANOVA to determine whether the between-groups variability exceeded the within-groups variability. c. significant ANOVA to determine which groups differ significantly from each other. d. nonsignificant ANOVA to determine which groups differ significantly from each other.

c. approach the baseline but never touch the baseline

406. The tails of a distribution are asymptotic, which means that the tails a. touch the baseline at approximately five standard deviations from the mean. b. curve upward from the baseline at approximately five standard deviations from the mean. c. approach the baseline but never touch the baseline. d. flatten out after approximately five standard deviations from the mean.

b. there are significant differences between the participants on the dependent variable.

407. When the "subjects" source is significant in an ANOVA source table, it means that a. there are significant differences associated with the independent variable. b. there are significant differences between the participants on the dependent variable. c. there is a significant interaction between subjects and the independent variable. d. there are significant pairwise comparisons using the Tukey HSD test.

b. Conduct a post hoc test to determine which means are significantly different from each other.

408. Suppose you find an overall significant F ratio in your one-way ANOVA. What should you do next? a. Write up your results in APA format. b. Conduct a post hoc test to determine which means are significantly different from each other. c. Conduct a follow-up study with new participants. d. Check the output to make sure the results are asymptotic.

b. Multiple-independent-groups design

409. Consult Table 11-1. What kind of research design is this? a. Multiple-correlated-groups design b. Multiple-independent-groups design c. Ex post facto research design d. Correlational research design

c. alcohol dose; ratings of responsibility

410. Consult Table 11-1. The independent variable in this study is __________ and the dependent variable in this study is ____________. a. sex of character; ratings of responsibility b. alcohol dose; sex of character c. alcohol dose; ratings of responsibility d. ratings of responsibility; alcohol dose

a. One-way ANOVA for independent samples

411. Consult Table 11-1. What kind of statistical analysis was conducted? a. One-way ANOVA for independent samples b. One-way ANOVA for correlated samples c. Two-factor ANOVA for independent samples d. Two-factor ANOVA for correlated samples

b. Because there are three groups.

412. Consult Table 11-1. Why are the degrees of freedom between groups equal to 2? a. Because there are two groups b. Because there are three groups. c. Because there are two significant differences d. Because the formula for df between is always 1 + 1

c. less; are

413. Consult Table 11-1. The p-value is ______ than .05; therefore, the results of the statistical analysis _____ significant. a. greater; are b. greater; are not c. less; are d. less; are not

c. The high dose group and the low dose group are significantly different from the no dose group, and the high dose and low dose group do not significantly differ from each other.

414. Consult Table 11-1. Which means are significantly different from each other? a. The high dose group is significantly different from the low dose group, and no other comparisons are significant. b. The high dose group is significantly different from the no dose group and the low dose group, and the low dose group and the no dose group do not significantly differ from each other. c. The high dose group and the low dose group are significantly different from the no dose group, and the high dose and low dose group do not significantly differ from each other. d. All three groups are significantly different from each other.

b. People who consumed alcohol (either a high or low dose) rated a perpetrator of sexual assault as significantly less responsible than people who consumed no alcohol.

415. Consult Table 11-1. Which of the following is the best written interpretation of the data? a. Consuming alcohol affects peoples' ratings of a sexual assault scenario. b. People who consumed alcohol (either a high or low dose) rated a perpetrator of sexual assault as significantly less responsible than people who consumed no alcohol. c. People who consumed a high dose of alcohol rated a perpetrator of sexual assault as significantly less responsible than people who consumed a low dose of alcohol or no alcohol at all. d. People who consumed a high dose of alcohol rated a perpetrator of sexual assault as significantly less responsible than people who consumed a low dose of alcohol, who rated the perpetrator as significantly less responsible than people who consumed no alcohol at all.

a. Multiple-groups design for correlated groups

416. Consult Table 11-2. What kind of research design is this? a. Multiple-groups design for correlated groups b. Multiple-groups design for independent groups c. Single-case experimental design d. Two-groups design for correlated groups

b. age of participants; scores indicating impressions of smokers

417. Consult Table 11-2. The independent variable in this study is __________ and the dependent variable in this study is ____________. a. age of participants; number of participants b. age of participants; scores indicating impressions of smokers c. scores indicating impressions of smokers; age of participants d. scores indicating impressions of smokers; number of participants

b. One-way ANOVA for correlated samples

418. Consult Table 11-2. What kind of statistical analysis was conducted? a. One-way ANOVA for independent samples b. One-way ANOVA for correlated samples c. Two-factor ANOVA for independent samples d. Two-factor ANOVA for correlated samples

b. Because there are three levels of the independent variable.

419. Consult Table 11-2. Why are the degrees of freedom for the age variable equal to 2? a. Because there are two levels of the independent variable. b. Because there are three levels of the independent variable. c. Because there are two significant differences. d. Because the formula for df between is always 1 + 1.

c. there were significant differences between the responses of the different children.

420. Consult Table 11-2. The SUBJECTS effect is significant, which means that a. the independent variable had a significant effect on the dependent variable. b. the dependent variable had a significant effect on the independent variable. c. there were significant differences between the responses of the different children. d. there were significant differences in the responses of 8-year-olds versus 10-year-olds versus 12-year-olds.

c. less; are

421. Consult Table 11-2. The p-value for age is ______ than .05; therefore, the results of the statistical analysis _____ significant. a. greater; are b. greater; are not c. less; are d. less; are not

c. The 12-year-old group differs significantly from the 10-year-old group, the 12-year-old group differs significantly from the 8-year-old group, and no other comparisons are significant

422. Consult Table 11-2. Which means are significantly different from each other? a. The 8-year-old group is significantly different from the 10-year-old group and the 12-year-old group, and the 10- and 12-year old groups do not differ significantly from each other. b. The 12-year-old group and the 10-year-old group differ significantly from each other, and no other comparisons are significant. c. The 12-year-old group differs significantly from the 10-year-old group, the 12-year-old group differs significantly from the 8-year-old group, and no other comparisons are significant. d. All three groups are significantly different from each other.

d. Twelve-year-olds hold more positive impressions of smokers than either 10- or 8-year-olds

423. Consult Table 11-2. Which of the following is the best written interpretation of the data? a. Age affects people's impressions of smokers. b. Eight-year-olds hold more positive impressions of smokers than either 10- or 12-year-olds. c. Twelve-year-olds hold more positive impressions of smokers than 10-year-olds, who hold more positive impressions of smokers than 8-year-olds. d. Twelve-year-olds hold more positive impressions of smokers than either 10- or 8-year-olds.

Questions 61 - 67 refer to the following computer output. In this study, participants were randomly assigned to consume one of three doses of alcohol: high, low, or none. Participants then read a scenario in which a male character sexually assaulted a female character. Participants rated the male character's responsibility for his behavior on a scale ranging from 1 (not at all responsible) to 20 (completely responsible).

Table 11-1 GROUP N MEAN STD DEV STD ERROR 1 (high dose) 10 14.80 1.32 0.42 2 (low dose) 10 16.10 1.79 0.57 3 (no dose) 10 18.60 1.17 0.37 ONEWAY ANOVA: ALCOHOL by RESPONSIBLE SUM OF MEAN SOURCE SQUARES DF SQUARES F RATIO PROB. BETWEEN GROUPS 74.60 2 37.30 17.70 .000 WITHIN GROUPS 56.90 27 2.11 TOTAL 131.50 29 POST HOC TEST: Tukey-HSD with significance level .05 * Indicates significant differences shown for pairings G G G r r r p p p 1 2 3 Mean ALCOHOL 14.80 Grp 1 16.10 Grp 2 18.60 Grp 3 * *

Questions 68 - 75 refer to Table 11-2. In this study, 10 children completed a survey regarding their impressions of smokers at age 8 and then again at age 10 and 12. Scores could range from 1 (extreme negative impression of smokers) to 20 (extreme positive impression of smokers).

Table 11-2 GROUP N MEAN STD DEV STD ERROR 1 (AGE 8) 10 9.70 5.89 1.86 2 (AGE 10) 10 10.40 5.58 1.76 3 (AGE 12) 10 11.80 5.94 1.88 ONEWAY ANOVA: SMOKING by AGE (CORR SAMP) SUM OF MEAN SOURCE SQUARES DF SQUARES F RATIO PROB. AGE 22.87 2 11.43 6.76 .006 SUBJECTS 879.63 9 97.74 34.71 .000 WITHIN CELLS 30.47 18 1.69 TOTAL 932.97 29 POST HOC TEST: Tukey-HSD with significance level .05 * Indicates significant differences shown for pairings G G G r r r p p p 1 2 3 Mean AGE 9.70 Grp 1 10.40 Grp 2 11.80 Grp 3 * *

b. 9

302. Consider the following scores: 1, 2, 2, 2, 3, 3, 4, 4, 6, 7, 8, 10. What is the range? a. 2 b. 9 c. 10 d. 4.5

c. nominal

245. You are using a(n) _________ scale of measurement if events are assigned to categories. a. interval b. ordinal c. nominal d. ratio

c. Nominal

247. Karen categorizes people in her sample as either male or female, which represents which scale of measurement? a. Ordinal b. Interval c. Nominal d. Ratio

b. abscissa; ordinate

298. For an experiment, the IV is plotted on the ________ and the DV is plotted on the ________. a. ordinate; y axis b. abscissa; ordinate c. x axis; abscissa d. ordinate; abscissa

c. Line graph

299. Leo randomly assigns half of his participants to read a neutral paragraph and half to read a biased paragraph. Participants rate the extent to which they liked the paragraph. Which kind of graph should he use to depict his results? a. Histogram b. Polygon c. Line graph d. Pie chart

b. variability.

300. The extent to which scores spread out around the mean is known as a. central tendency. b. variability. c. a Type II error. d. a Type I error.

c. range

301. To find the _______, subtract the smallest score from the largest score. a. standard deviation b. mode c. range d. variance

a. line graph

293. Researchers frequently present the results of an experiment in a a. line graph. b. histogram. c. pie chart. d. frequency polygon.

d. ordinate.

294. The vertical or y axis of a graph is known as the a. abscissa. b. pie axis. c. line axis. d. ordinate.

a. abscissa.

295. The horizontal or x axis of a graph is known as the a. abscissa. b. pie axis. c. line axis. d. ordinate.

c. two-thirds

297. Generally, the y axis should be about _________ as tall as the x axis is long. a. one-half b. one-third c. two-thirds d. three-fifths

d. ordinate; abscissa

296. The y axis of a graph is also known as the ________ and the x axis of a graph is also known as the ________. a. abscissa; ordinate b. Type I axis; abscissa c. ordinate; Type I axis d. ordinate; abscissa

c. frequency polygon.

290. If we place a dot in the middle of each bar in a histogram, connect the dots, and remove the bars, we have created a a. line graph. b. bar graph. c. frequency polygon. d. pie chart.

c. Histogram

291. Which of the following graphs can be used interchangeably with a frequency polygon? a. Bar graph b. Pie chart c. Histogram d. Line graph

a. The scale of measurement for the dependent variable determines the kind of statistical test that can be conducted.

248. Why is it important to understand scales of measurement? a. The scale of measurement for the dependent variable determines the kind of statistical test that can be conducted. b. Scales of measurement are integral for inferential statistics (but not necessarily descriptive statistics). c. Scales of measurement are integral for descriptive statistics (but not necessarily inferential statistics). d. Researchers can only analyze data on interval and ratio levels of measurement.

d. ordinal

249. Tammy conducted a study in which participants rank-ordered their favorite free-time activities. Tammy used a(n) _________ scale of measurement. a. ratio b. nominal c. interval d. ordinal

c. When variables are measured on an ordinal scale of measurement, the intervals between numbers are not necessarily equal

250. Which of the following is a limitation of the ordinal scale of measurement? a. The ordinal scale of measurement represents a simple classification system. b. There is no way to measure central tendency for variables measured on the ordinal scale of measurement. c. When variables are measured on an ordinal scale of measurement, the intervals between numbers are not necessarily equal. d. All of the above are limitations of the ordinal scale of measurement.

b. ordinal

251. If we rank the winners of a horse race (first, second, third), we are using a(n) ____________ scale of measurement. a. ratio b. ordinal c. interval d. nominal

c. interval

252. If there are equal intervals between numbers but no true zero point, we are using a(n) __________ scale of measurement. a. ordinal b. ratio c. interval d. nominal

b. Because there are equal intervals between scores but no true zero point

254. Why does temperature in Fahrenheit represent an interval scale of measurement? a. Because it has a true zero point b. Because there are equal intervals between scores but no true zero point c. Because the zero point indicates the absence of heat d. None of the above

c. there are equal intervals between scores but not a true zero point.

255. ACT scores are measured on an interval scale of measurement because a. ACT scores are rank ordered and there are not equal intervals between scores. b. there is a true zero point. c. there are equal intervals between scores but not a true zero point. d. the scores represent mutually exclusive categories.

d. ratio

257. Number of errors on a math test represents a(n) __________ scale of measurement. a. nominal b. interval c. ordinal d. ratio

c. mode

264. The _________ is the only measure of central tendency that can be used for nominal data. a. mean b. median c. mode d. range

b. mode.

265. Joseph would like to find a measure of central tendency for his occupation variable (measured as "sales," "teacher," or "other"). Joseph should use the a. median. b. mode. c. mean. d. It is impossible to find central tendency for this variable.

c. median

266. The _________ is the score that divides the distribution in half. a. mean b. mode c. median d. variance

d. Rank order the scores from lowest to highest.

267. What is the first step in calculating the median? a. Add up all the scores. b. Locate the most frequently occurring score. c. Count the number of scores. d. Rank order the scores from lowest to highest.

b. 3

268. Consider the following scores: 2, 2, 2, 4, 5, 9. What is the median? a. 2 b. 3 c. 4 d. 2.5

a. Add up all the scores.

273. What is the first step in calculating the mean? a. Add up all the scores. b. Locate the most frequently occurring score. c. Rank-order the scores from lowest to highest. d. Locate the least frequently occurring score.

b. 2

277. Consider the following scores: 1, 1, 1, 3, 4. What is the mean? a. 1 b. 2 c. 10 d. The mean cannot be calculated for these scores

b. mean.

278. Isabelle would like to calculate a measure of central for the number of errors rats made while running a maze. Isabelle should calculate the a. range. b. mean. c. mode. d. standard deviation

a. When there are a limited number of extreme scores in the distribution

282. Under what circumstances should you calculate the median instead of the mean? a. When there are a limited number of extreme scores in the distribution b. When scores are measured on a nominal scale of measurement c. When the scores form a bimodal distribution d. When the scores are all the same

c. Median

283. Consider the following amounts that were donated to charity: $1, $1, $1, $5, $10, $10, $100. What would be the best measure of central tendency in this case? a. Mean b. Mode c. Median d. Standard deviation

d. Pie chart

284. Casey needs to graph percentages that total 100%. Casey should use which kind of graph? a. Histogram b. Line graph c. Polygon d. Pie chart

a. it is not possible to calculate a mean.

285. When data are presented in a pie chart, a. it is not possible to calculate a mean. b. it is not possible to calculate a mode. c. it is possible to calculate standard deviation. d. it is possible to calculate a correlation coefficient.

c. histogram.

286. A graph in which the frequency for each category of a quantitative variable is represented as a vertical column which touches the adjacent column is called a a. bar graph. b. frequency polygon. c. histogram. d. pie chart.

c. histogram.

287. April would like to create a frequency graph of the following quiz scores: 1, 1, 1, 2, 2, 4, 4, 4, 5, 5, 5, 8, 8, 9, 9, 9, 10. April should use a a. bar graph. b. pie chart. c. histogram. d. None of the above.

d. bar graph.

288. A graph in which the frequency for each category of a qualitative variable is represented as a vertical column which does not touch the adjacent column is called a a. pie chart. b. histogram. c. line graph. d. bar graph.

d. bar graph.

289. Jordan would like to graph the number of men versus women in her class. Jordan should use a a. histogram. b. line graph. c. frequency polygon. d. bar graph.

d. Most scores cluster in the middle, with fewer scores as you move away from the middle

307. Which of the following accurately depicts a normal distribution? a. Most scores occur in the extreme ends of the distribution and few scores occur in the middle. b. Most scores cluster on the right-hand side of the graph, with fewer scores on the left-hand side. c. Most scores cluster on the left-hand side of the graph, with fewer scores on the right-hand side. d. Most scores cluster in the middle, with fewer scores as you move away from the middle.

a. the mean, median, and mode all have the same value.

308. In a normal distribution, a. the mean, median, and mode all have the same value. b. the mean has a higher value than the median and the mode. c. the mean has a lower value than the median and the mode. d. the mode has the highest value, followed by the median and then the mean.

b. 70; 80

309. Suppose exam scores are normally distributed with M = 70 and SD = 10. According to the text, 34.13% of exam scores should fall between ________ and ________. a. 60; 80 b. 70; 80 c. 69; 71 d. 70; 100

b. 68.26%

310. Suppose exam scores are normally distributed with M = 80 and SD = 5. Approximately what percentage of scores fall between the scores of 75 and 85? a. 34.13% b. 68.26% c. 13.59% d. 2.15%

a. As you move away from the mean, the scores occur progressively less frequently.

312. In a normal distribution, why isn't the percentage of scores between 0 and 1 SD above the mean the same as the percentage of scores between 1 and 2 SDs above the mean? a. As you move away from the mean, the scores occur progressively less frequently. b. As you move away from the mean, the scores occur progressively more frequently. c. The scores are more spread out as you move away from the mean. d. The scores are less spread out as you move away from the mean.

c. Economics

313. Suppose in your English class, you earned a 70 on the first test (the class mean was 65 with SD = 3). In Math, you earned a 70 on the first test (the class mean was 65 with SD = 5). In Economics, you earned a 70 on the first test (the class mean was 65 with SD = 2). In which class did you do the best relative to the other students in the class? a. English b. Math c. Economics d. You did the same in all three classes relative to the other students.

a. 1 SD below the mean.

314. Suppose you earned an 80 on an exam. The class mean was 82 with SD = 2. Your exam score is a. 1 SD below the mean. b. 1 SD above the mean. c. 2 SDs below the mean. d. 2 SDs above the mean.

d. correlation coefficient

315. A __________ is a single number representing the degree of relation between two variables. a. mean b. median c. mode d. correlation coefficient

c. -1; +1

316. The value of a correlation coefficient can range from ____ to _____. a. 0; +1 b. -1; 0 c. -1; +1 d. -10; +10

c. -1

317. A correlation of ___ indicates a perfect negative relationship between two variables. a. 0 b. 1 c. -1 d. - .5

a. positive

318. Consider the following scores: X Y 8 9 3 4 5 5 1 2 4 2 7 9 These scores depict a ________ correlation. a. positive b. negative c. zero d. curvilinear

a. prediction.

319. Correlation coefficients are used for a. prediction. b. understanding causality. c. both prediction and understanding causality. d. neither prediction nor understanding causality.

d. All of the above.

321. Which of the following must be true in order to calculate the Pearson correlation coefficient? a. The x variable must be interval or ratio scale of measurement. b. The y variable must be interval or ratio scale of measurement. c. The data must appear to be linear. d. All of the above.

c. determine whether a statistical result is significant.

322. The purpose of inferential statistics is to a. provide a measure of central tendency and a measure of variability for the data. b. determine whether a correlation coefficient is positive, negative, or zero. c. determine whether a statistical result is significant. d. All of the above.

d. null

323. The _______ hypothesis states that all differences between groups are due to chance. a. alternative b. research c. statistical d. null

b. not significant.

324. If our statistical result occurs often by chance, we conclude that it is a. significant. b. not significant. c. proven. d. not proven.

a. significant.

325. If our statistical results occurs rarely by chance, we conclude that it is a. significant. b. not significant. c. proven. d. not proven

a. A result is considered significant if it would occur 5 (or fewer) times out of 100 when the null hypothesis is true.

326. What does a ".05 level of significance" mean? a. A result is considered significant if it would occur 5 (or fewer) times out of 100 when the null hypothesis is true. b. There is a 5% chance that the null hypothesis is true. c. There is a 5% chance of proving your results. d. There is a 5% chance of making a Type II error

b. t test.

327. An inferential statistical test used to evaluate the difference between two means is known as a a. one-factor ANOVA. b. t test. c. z test. d. correlational test.

a. degrees of freedom.

333. The ability of a number in a specified set to assume any value is known as a. degrees of freedom. b. a t test. c. a one-tailed test. d. a Type II error.

b. one-tailed; two-tailed

334. Directional hypotheses are associated with _____ tests and nondirectional hypotheses are associated with _______ tests. a. two-tailed; one-tailed b. one-tailed; two-tailed c. one-tailed; three-tailed d. two-tailed; three-tailed

b. one-tailed test.

335. It is somewhat easier to find a significant result when using a a. two-tailed test. b. one-tailed test. c. correlational research design instead of an experimental research design. d. case study design instead of an experimental research design.

b. the critical region for a two-tailed test is smaller than the critical region for a one-tailed test.

336. It is somewhat easier to find a significant result when using a one-tailed test rather than a two-tailed test because a. the critical region for a one-tailed test is smaller than the critical region for a two-tailed test. b. the critical region for a two-tailed test is smaller than the critical region for a one-tailed test. c. the critical region for a one-tailed test is in the middle of the distribution instead of in the tails. d. the critical region for a two-tailed test is in the middle of the distribution instead of in the tails.

b. accepting the experimental hypothesis when the null hypothesis is true.

337. A Type I error refers to a. accepting the null hypothesis when the experimental hypothesis is true. b. accepting the experimental hypothesis when the null hypothesis is true. c. accepting both the null hypothesis and the experimental hypothesis when neither is true. d. accepting neither the null hypothesis nor the experimental hypothesis when both are true.

c. Researchers can change the significance level from .05 to .01

338. How can researchers lower the probability of making a Type I error? a. Researchers can change their research design from an experiment to a correlational study. b. Researchers can decrease the sample size. c. Researchers can change the significance level from .05 to .01 d. Researchers can change the significance level from .01 to .05.

b. Type II

339. Accepting the null hypothesis when the experimental hypothesis is true is called a(n) _________ error. a. Type I b. Type II c. experimental d. null

a. α

340. The symbol for a Type I error is: a. α b. β c. Σ d. Φ

d. Not enough information to determine.

Nora would like to conduct an experiment to determine whether behavior modification techniques can help children eliminate bedwetting. She obtains a sample of children who wet the bed and randomly assigns half to the behavior modification therapy and half to a control group who receive no therapy. After six months, she measures how often children in each group wet the bed. 328. Suppose the results show that children in the control group wet the bed on average M = 5.50 times per week and children in the therapy group wet the bed M = 1.60 times per week. Do these results show that the therapy was effective? a. Yes; the means are slightly different from each other. b. Yes; the means are very different from each other. c. No; the means are not different enough from each other. d. Not enough information to determine.

b. two-tailed test.

Nora would like to conduct an experiment to determine whether behavior modification techniques can help children eliminate bedwetting. She obtains a sample of children who wet the bed and randomly assigns half to the behavior modification therapy and half to a control group who receive no therapy. After six months, she measures how often children in each group wet the bed. 330. Consider the following hypothesis: "If children undergo behavioral modification therapy, then they will have different rates of bedwetting than children in the control group." If this is Nora's hypothesis, then she should use a a. one-tailed test. b. two-tailed test. c. three-tailed test. d. correlational research design.

a. The results are significant; children treated with behavioral modification therapy wet the bed less often than children in the control group.

Nora would like to conduct an experiment to determine whether behavior modification techniques can help children eliminate bedwetting. She obtains a sample of children who wet the bed and randomly assigns half to the behavior modification therapy and half to a control group who receive no therapy. After six months, she measures how often children in each group wet the bed. 331. Suppose Nora obtains the following printout of information: GROUP N M SD Therapy 10 1.60 1.07 Control 10 5.50 0.85 t = -9.00 df = 18 p = .001 What decision should Nora make? a. The results are significant; children treated with behavioral modification therapy wet the bed less often than children in the control group. b. The results are not significant; children treated with behavioral modification therapy wet the bed less often than children in the control group. c. The results are significant; children treated with behavioral modification therapy and children in the control group did not differ in terms of bedwetting. d. The results are not significant; children treated with behavioral modification therapy and children in the control group did not differ in terms of bedwetting.

d. 2.101

Nora would like to conduct an experiment to determine whether behavior modification techniques can help children eliminate bedwetting. She obtains a sample of children who wet the bed and randomly assigns half to the behavior modification therapy and half to a control group who receive no therapy. After six months, she measures how often children in each group wet the bed. 332. Suppose Nora used α = .05 for a two-tailed test. According to the t distribution table, what value from the table did Nora's t value have to exceed in order for it to be considered significant? a. 1.725 b. 1.734 c. 2.086 d. 2.101