PSY 250 Deskovitz Exam 3

3

A researcher computes a 2 × 4 between-subjects ANOVA. What are the degrees of freedom for Factor B for this study?

2

There are ______ factors in a 2 × 3 ANOVA design.

estimated

A key difference between a t statistic and a z statistic is that the standard error is ______ to compute a t statistic.

-1; +1

The correlation coefficient ranges between ______ and ______.

The related-samples t test had greater power to detect the effect

Two researchers analyze the same data set. Researcher A uses a two-independent-sample t test and decides to retain the null hypothesis. Researcher B uses a related-samples t test and decides to reject the null hypothesis. Which of the following is a likely explanation for the disparity in the decisions made?

A and B interaction

Using a two-way between-subjects ANOVA with Factor A (gender: male, female) and Factor B (type of employment: blue collar, white collar), a researcher found that scores for men and women significantly varied across the levels of the second factor (type of employment). In this study, the researcher found a significant ______.

-0.90

Which of the following indicates the strongest correlation? a. r = -0.57 b. r = +0.78 c. r = -0.90 d. r = +0.88

Tukey's HSD test

Which of the following post hoc tests is associated with the least power to detect an effect?

one-sample t test (one sample and making estimation)

You read about a study testing whether night shift workers sleep the recommended 8 hr per day. Assuming that the population variance of sleep (per day) is unknown, what type of t test is appropriate for this study?

never

A correlation coefficient can ______ demonstrate cause

Not enough information to give answer

A local elementary school determined that the average number of volunteers for their "Step into Spring" annual fundraiser has been 14 persons on average (per event). After taking additional measures to recruit volunteers this year, they got 28 people to volunteer. Test whether these additional measures increased the number of volunteers at a .05 level of significance.

matched-samples design

A researcher asks a sample of brothers and sisters to rate how positive their family environment was during childhood. In this study, the differences in ratings between each brother and sister pair were compared. The type of design described here is called a ______.

.23 (120/518)

A researcher conducts a 2 × 3 between-subjects ANOVA. She finds a significant interaction, where SSAB = 120 and SST = 518. What is the effect size for this test using eta-squared?

(3, 84)

A researcher conducts a study in which k = 4 and n = 22 in each group. What are the degrees of freedom for the one-way between-subjects ANOVA?

a. a related-samples t test c. a one-way within-subjects ANOVA

A researcher measures anxiety levels among participants in the presence and absence of a fearful stimulus. If the same participants are observed in each group, then what type of statistical design is appropriate for this study?

c. 27; (n-1), 9 x 3

A researcher measures attractiveness ratings of a male confederate among 30 women who were told the confederate was either single, dating, or married (n = 10 per group). What are the degrees of freedom for error for the one-way between-subjects ANOVA?

the speed at which people eat

A researcher measures the extent to which the speed at which people eat (in minutes) predicts calorie intake (in kilocalories). Which factor is the predictor variable in this example?

.01

A researcher measures the following correlation between number of years of education and life satisfaction: r = +.08. What is the value of the coefficient of determination?

two-independent-sample t test

A researcher records differences in ratings of emotion among participants watching either a drama or a romance film. Assuming that the population variance is unknown, what type of t test is appropriate for this study?

the interval estimate is not given

A researcher reports that college students consume an average of 3.6 alcoholic drinks per week. What is the interval estimate in this example

not enough information given to answer

A researcher reports that the mean time it takes to complete an experimental task is 1.4 ± 8.0 (M ± SD) s. If the null hypothesis was that the mean equals 1.0, then what is the effect size for this test using estimated Cohen's d?

10.23

A researcher reports the following regression equation for two variables, X and Y: Y= 5.10X - 1.50. If X = 2.30, then what is the value of Y ?

34% (median)

A researcher reports with 90% confidence that 31-37% of Americans believe in ghosts. What is the point estimate for this interval?

53 (n-1)

A researcher selects a sample of 54 participants who are assigned to participate in a study with one group. What are the degrees of freedom for this one sample t-test?

different participants are assigned to each of two groups the population variance is unknown participants are observed one time in a given group all of these

Computing a two-independent-sample t test is appropriate when ______.

.5 (18/36)

In a study with 3 groups and 13 participants in each group, the sum of squares for the within-groups source of variation is 18. What is the value for the mean square within-groups in this study?

a. degrees of freedom error b. degrees of freedom denominator c. degrees of freedom within-groups d. all of these

The degrees of freedom for error is called ______.

smaller

The less that scores overlap between groups, the ______ the error variance.

one is continuous and one is dichotomous

The point-biserial correlation coefficient is a measure of the direction and strength of the linear relationship between two variables, where ______.

between-groups variability

The source of variation that is associated with differences between groups in a study is called ______.

observing the same participants in each group

The term "within-subjects" refers to ______.

(nD - 1)

What are the degrees of freedom for the related-samples t test?

both

A researcher conducts two studies on self-perception. In Study 1, 24 participants rate how positively they view themselves (on a 5-point scale) in one of three groups (n = 8 per group). In Study 2, the researcher conducts a similar study, except that k = 3 and n = 8. If SSBG = 28 and SSE = 42 in both studies, then in which study will the decision be to reject the null hypothesis at a .05 level of significance for a one-way between-subjects ANOVA?

Study 2

A researcher conducts two studies using the one-way between-subjects ANOVA. The sum of squares between groups is smaller in Study 1 than in Study 2; the sum of squares total is the same in both studies. Using eta-squared, in which study will the effect size be larger?

following a significant ANOVA test to make pairwise comparisons

Post hoc tests are computed ______.

t statistic

The ______ is an inferential statistic used to determine the number of standard deviations in a t distribution that a sample mean deviates from the mean value or mean difference stated in the null hypothesis.

a stronger relationship between two factors

The correlation coefficient ranges from -1.0 to +1.0, with values closer to ±1.0 indicating ______.

40

The following is a summary of a one-way between-subjects ANOVA: F(2, 37) = 3.42, p < .05, = .12. How many participants were observed in this study?