ES 350 Exam 2

For a group of normally distributed scores with a mean of 30 and a standard deviation of 6, the middle 68% of the scores will be between A. 30 and 36 B. 18 and 42 C. 24 and 36 D. 12 and 48

24 and 36

In logistic regression, one is able to predict a continuous variable membership in one of three or more groups a binary outcome variable multiple criterion variables

a binary outcome variable

The term that describes the position (right or left; positive or negative) of the hump in the curve of a distribution is A. skewness B. kurtosis C. the stem D. the leaves

skewness

To determine whether data are normally distributed, one can test to see whether the curve is shifted to the left or right. This shift is called A. kurtosis B. robustness C. dispersion D. skewness

skewness

An important probability concept is relative frequency. Relative frequency is the idea that a normal coin will land on heads 50 times out of 100 the idea that a coin that lands on heads 60 times out of 100 is rigged the idea that a normal coin may land on heads 40 times out of 100 all of the above

the idea that a normal coin may land on heads 40 times out of 100

A statistical test that provides information about the relationship between two continuous variables is A. t test B. ANOVA C. chi-square test D. Pearson product moment coefficient of correlation

Pearson product moment coefficient of correlation

What is the median score for the following set of numbers? (3, 11, 8, 13, 5, 3, 6) A.5 B.6 C.7 D.8

6

The researcher obtained a significant F from the ANOVA. Partial 2 was found to be .30. This is interpreted to mean that 9% of the total variance is accounted for by treatment 15% of the total variance is accounted for by error 30% of the total variance is accounted for by the treatments 70% of the total scores are due to the treatments

30% of the total variance is accounted for by the treatments

What is the mode for the following set of numbers? (5, 10, 4, 1, 4, 5, 12, 8, 9, 4) A.4 B.4 and 5 C.5 D.5.5

4

A researcher finds a correlation of .70 between popularity ratings and self-concept scores. What percentage of common association can be inferred between the two variables? 35% 49% 60% 70%

49%

Why can't you just run multiple t-tests instead of running an ANOVA (and post-hoc tests if overall ANOVA is significant)? A. Because you would be violating the assumption of normality B. Because you would be inflating your type II error rate (i.e., mistakenly reducing chances of finding statistical significance) C. Because you would be inflating your type I error rate (i.e., mistakenly increasing chances of finding statistical significance) D. None of the above

Because you would be inflating your type I error rate (i.e., mistakenly increasing chances of finding statistical significance)

Why is standard deviation important in terms of considering the sample? A. If standard deviation is large, then the mean is likely to be a good representative score for the sample. B. If standard deviation is small, then the mean is likely to be a good representative score for the sample. C. If standard deviation is large, then the mode is the best score to represent the sample. D. If standard deviation is small, then the mean is likely to fall outside of the range of scores.

If standard deviation is small, then the mean is likely to be a good representative score for the sample.

A statistical test that provides information about the relationship between two continuous variables is A. ANOVA B. chi-square test C. Pearson product moment coefficient of correlation D. t test

Pearson product moment coefficient of correlation

Which one of the following statements does not describe an advantage of repeated measures? Repeated measures control for individual differences among participants. Repeated measures can eliminate the influence of some unwanted variable. Repeated measures are more economical because fewer participants are needed. Repeated measures allow the researcher to study a phenomenon across time.

Repeated measures can eliminate the influence of some unwanted variable.

A Pearson's correlation of .00 between two variables indicates: A. a perfect positive relationship B. independence (no association) between the variables C. a perfect negative relationship D. a relationship of unknown degree

independence (no association) between the variables

A variable that is a moderator is one that explains the effects of variable X on variable Y influences the strength of the effect of variable X on variable Y serves as a mechanism from variable X to variable Y has a moderate-size effect on variable Y

influences the strength of the effect of variable X on variable Y

The standard deviation represents the A. error in measurement B. spread of scores about the mean C. single score that best expresses the group's performance D. error in sampling from the population

spread of scores about the mean

If a researcher finds a small difference in average test scores between a large sample (over 700) of experimental participants and a large sample (same size) of control participants, it is very likely that the difference is statistically significant and has a high degree of meaningfulness not statistically significant but has a high degree of meaningfulness statistically significant but does not have a high degree of meaningfulness neither statistically significant nor meaningful

statistically significant but does not have a high degree of meaningfulness

After a population of 1,000 high school seniors is divided by sex and size of school attended, the random selection of a sample to represent these proportions of the population is called A. systematic sampling B. matched-pair sampling C. stratified random sampling D. cluster sampling

stratified random sampling

Imagine you are rolling a 10-sided die that is equally weighted and with each side showing a number from one to ten. If you roll the die 10 times and you roll a three 4 of those 10 times, what does this tell you? A. The die must be unequally weighted. B. The relative frequency may not be the same as the theoretical frequency. C. If you roll the dice another 10 times, you are highly likely to roll a three 4 times. D. If you roll the dice another 100 times, you are highly likely to roll a three 40 times.

The relative frequency may not be the same as the theoretical frequency.

Which hypothesis is stated in the null form? There is no difference between the vocabulary scores of average- and high-ability students. The math achievement scores from School A are significantly higher than the scores from School B. The perceptual-motor development of first-grade girls is higher than that of first-grade boys. There is a positive relationship between attitude toward school and achievement scores.

There is no difference between the vocabulary scores of average- and high-ability students.

Variables that show a relationship with one another may be statistically correlated. Referring to the figure below, what might you expect in terms of the correlation? A. a curvilinear relationship B. a positive linear relationship C. a negative linear relationship D. no relationship

a positive linear relationship

A null hypothesis is nearly always the same as the research hypothesis a statistical hypothesis that assumes that the participants in two treatment groups were unequal before treatment began a statistical hypothesis that assumes that there is a difference among the effects of treatments a statistical hypothesis that assumes that there is no difference among the effects of treatments

a statistical hypothesis that assumes that there is no difference among the effects of treatments

Which option is a common test statistic? t F r All of the above

all of the above

If the null hypothesis is false, one may assume the research hypothesis is the explanation for the results if p < .05 there is no experimenter bias all other possible explanations have been controlled there is a reasonable number of participants in each group

all other possible explanations have been controlled

A researcher sought to find out which of two exercises was more effective in building endurance. One group used exercise A, and another group used exercise B. At the end of study, the researcher should compare the two groups' scores with a dependent samples t test an independent samples t test the Spearman rank-difference correlation multiple regression

an independent samples t test

When the purpose of the research is to determine the effects of one independent variable (e.g., four groups) on one dependent variable (e.g., self-concept), the best choice of a statistical analysis is analysis of variance multiple t tests discriminant analysis MANOVA

analysis of variance

Which of the following is an example of snowball sampling? A. recruiting a third-grade class from a local elementary school B. randomly selecting names from a high school yearbook C. selecting every 20th name from a list of freshmen at a university D. asking college athletes to recruit their teammates

asking college athletes to recruit their teammates

For scores from a test to have good content validity, which of the following statements must be true? The test is highly correlated with the final grade in the course. The test adequately samples what was covered in the course. The percentage of points for each topic area reflects the amount of emphasis given to that topic. b and c only a, b, and c

b and c only

A statistical technique that tests for significant differences between observed and expected frequencies of occurrence is analysis of covariance canonical correlation Mann-Whitney test chi square

chi square

Which of the following is a technique for providing information about the reliability of an instrument? bivariate prediction coefficient alpha factor analysis chi square

coefficient alpha

Of the following, which is a nonparametric statistical test? discriminant analysis dependent t test ANOVA contingency coefficient

contingency coefficient

A chi-square analysis compares the responses to a question on recreational preferences of males and females at three grade levels. The resulting two-way classification structure is called a frequency distribution contingency table stem-and-leaf display Yates' continuity table

contingency table

Prediction studies use which of the following as the basic analysis technique? ANOVA correlation factor analysis multiple-range comparison

correlation

A measure that expresses the difference between the experimental and control group in standard deviation units is the effect size r mean chi square

effect size

A researcher decides to use an alpha of .01 and a power of .80. To determine the needed sample size the researcher must also ascertain the expected beta stem-and-leaf distribution effect size skewness

effect size

What two things can statistics do? A. establish significance and assess the magnitude of the effect B. establish significance and assess the meaningfulness of the effect (practical meaning) C. prove a hypothesis and assess the meaningfulness of the effect D. prove a hypothesis and assess the magnitude of the effect

establish significance and assess the magnitude of the effect

In which of the following circumstances would you be likely to set alpha = .01 instead of alpha = .05? if you were conducting a pilot study and wanted to give yourself every opportunity to identify a significant result if you were testing a drug that had the potential to save lives but also had serious side effects if you were not concerned about the risk of making a type I error if you had a very small sample size

if you were testing a drug that had the potential to save lives but also had serious side effects

A teacher wishes to determine the reliability of three trials on a performance test. He uses ANOVA to obtain the reliability coefficient. This technique is called interclass correlation partial correlation equivalence correlation intraclass correlation

intraclass correlation

The property of a distribution of scores that relates to how peaked or flat the curve is called kurtosis robustness dispersion skewness

kurtosis

If two measures have a high positive correlation, and a person has a low score on one measure, her score on the other measure is most likely to be low high the same score dependent on whether one variable is the cause of the other

low

In discriminant function analysis, one is able to predict a continuous variable membership in one of three or more groups the probability of an occurrence a multiple criterion variable

membership in one of three or more groups

Data such as sex, city of residence, or political party affiliation are what kind of measure? nominal ratio interval ordinal

nominal

Chi square is appropriate for which one of the following types of data? small samples ratios observed frequencies percentages

observed frequencies

In multiple regression, one is able to predict two or more criteria from two or more predictors two or more criteria from one predictor one criterion from one predictor one criterion from two or more predictors

one criterion from two or more predictors

Power is defined as the probability of A. failing to reject a false null hypothesis B. rejecting a false null hypothesis C. rejecting a true null hypothesis D. entertaining a false null hypothesis

rejecting a false null hypothesis

If a thermometer measured the temperature in an oven as 400° five days in a row when the temperature was actually 337°, this measuring instrument would be considered reliable and valid valid but not reliable reliable but not valid unreliable and invalid

reliable but not valid

The type of scale that uses two adjectives, such as Worthless and Valuable, is a Thorndike scale Thurstone scale semantic differential scale Likert scale

semantic differential scale

When an experimenter states that the level of significance is at the .05 level, he or she is setting the probability of committing which type of error? type I error type II error egregious error design error

type I error

If the researcher fails to reject the null hypothesis when there really is a difference A. one-tailed test B. two-tailed test C. type I error D. type II error

type II error

If the researcher fails to reject the null hypothesis when there really is a difference, this is an example of a one-tailed test two-tailed test type I error type II error

type II error