SOCI 313: Final Exam Review

If we calculate an r of .60, the proportion of the variation of Y that is explained by X is

.36 (.6)^2

Information derived from survey data that examines the relationship between the race of a person and his employment status yields a lambda of .20. This information indicated that we are ____% better off knowing race when attempting to predict employment status.

20

A researcher was interested in studying the effects of days spent in drug rehabilitation and number of subsequent arrests and found the following regression equation: y=6.13-.59x. If a person spends 3 days in rehab what would be their predicted number of future arrests?

4.36 plug 3 into x

Which of the following is NOT true of hypothesis testing

A relevant statistic is calculated from population information and summarized into a test statistic

Which of the following is NOT true when computing Cramer's V? a.it is appropriate for 2 x 2 tables b.it is based on chi-square c.it is an example of PRE measure d.it is a measure of association for nominal variables

A. it is an appropriate for 2 x 2 tables & C. it is an example of a PRE measure

What would be the most appropriate test of significance for research situations in which we have an interval ratio dependent variable and an independent variable with three or more categories?

ANOVA Test

Which assumption about level of measurement is made for the Chi square test?

All variables are nominal in level of measurement

A researcher asked a sample of dual career families about the amount of the family budget contributed by the wife's job (y) and the total number of children (x). Pearson's r for this relationship is -.34. Which of the following is an appropriate interpretation of these results? a.for every dollar contributed by the wife the number of children increases by .34 b.for every additional child, the wife must work longer hours c.every additional child lowers the economic wellbeing of the family d.as number of children increase, the percentage of the budget contributed by the wife decreases

As number of children increases, amount contributed by wife decreases

In order to examine which of the independent variables has the strongest effect on the dependent variable you would use a. unstandardized partial slopes b. standardized partial slopes c. Y intercepts d. ANOVA

B. standardized partial slopes

The characteristic of a relationship between two variables that must be analyzed for a full understanding of the relationship is

Bivariate Analysis

To conduct a chi square test, the variables must first be organized into a ....

Bivariate table

A study found that parenting classes were closely related to a child's performance in school (as measured by GPA). Each week of parenting classes taken by a child's parents raised their high school GPA by .23 points. If there was an intercept of 1.68, what would your regression equation look like? a.2.52 b.3.21 c.3.52 d.3.79

C. 3.52

Gamma provides a summary measure of the a. existence of a bivariate relationship. b. strength of a relationship. c. direction of a relationship. d. All of the above

D. all of the above

The sampling distribution for the ANOVA test is...

F-distribution

Like lambda ____ uses proportional reduction in error logic to determine relationships

Gamma

Which measure of association is based on predicted the order of pairs of cases?

Gamma

If we cannot reduce our errors of prediction for the order of pairs of cases on one variable by predicting from the order of pairs of cases on the other variable.

Gamma will be zero

A researcher can demonstrate a strong association between gender and income. Which variable is independent?

Gender

Correct way to interpret 95% confidence interval

If repeated samples were taken and the 95% confidence interval was computed for each sample, 95% of the intervals would contain the population mean. A 95% confidence interval has a 0.95 probability of containing the population mean. 95% of the population distribution is contained in the confidence interval.

A bivariate table shows the association between gender and whether or not a person ever attends formal religious services. Lambda was .34. What may be concluded?

Knowing a person's gender improves our ability to predict whether or not they attend religious services by 34%.

One key assumption of correlation analysis is that the variables have an essentially _______ relationship.

Linear

The Y intercept is the point where

Point where the regression line crosses the Y axis

The null hypothesis for ANOVA states that....

Population means are equal

What does PRE stand for?

Proportional reduction in Error

A random sample of LA residents averages 1.4 children while the state as a whole averages 1.7 children. The Z score computed in this test is 2.78. The alpha level is .05 and the critical Z value is + or - 1.96. Therefore, the difference in the size of family...

SKIP

A random sample of San Diego residents averages 1.4 children while the state as a whole averages 1.7 children. The Z score computed in this test is .78. The alpha level is .05 and the critical Z value is + or - 1.96. Therefore, the difference in the size of family... a. is due to random chance b. does not reflect the situation of all the people in San Diego c. is statistically significant d. all of the above

SKIP

Which of the following was presented as a reason for the decline in the accuracy of modern day polling?

SKIP

hypothesis testing

hypothesis test is a statistical test that is used to determine whether there is enough evidence in a sample of data to infer that a certain condition is true for the entire population

When we have an interval-ratio dependent variable and are comparing two groups the appropriate test of significance is the _________. When we have an interval ratio dependent variable and are comparing three or more groups, the appropriate test of significance is the _______.

T-Test; ANOVA

When we are interested in running a t-test but have small sample sizes we should use

T-distribution

One limitation of the Chi square test (and all tests of hypothesis) is that they cannot tell us if relationship between variables are....

important

The regression equation for a particular relationship is Y = 10 + (.78) X1 + (-.54) X2. Which conclusion is consistent with this

The two independent variables have opposite effects on the dependent.

A two tailed hypothesis test is used when

a statistical test in which the critical area of a distribution is two-sided and tests whether a sample is greater than or less than a certain range of values. If the sample being tested falls into either of the critical areas, the alternative hypothesis is accepted instead of the null hypothesis

In a study of the relationship between geographical mobility (number of times a person has changed residences) and number of friends, Pearson's r² is reported as .40. Which of the following would be a correct interpretation?

There is a strong positive relationship between number of friends and mobility

Which of the following does NOT describe homoscedasticity?

Variance of the Y scores is uniform for all value of X or the Y scores are evenly spread about and below the regression line

We have rejected the null hypothesis in an ANOVA test. This means that the variation _____ with the samples is significantly greater than the variation _____ the samples.

between, within

As one variable decreases and the other variable decreases this is an example of...

positive relationship

In the ANOVA test, if the null hypothesis is true....

sample means should be roughly equal in value

A researcher examines the relationship between poverty and crime rates for 100 metropolitan areas and finds a zero-order correlation of .37. She controls for the percent of families that are headed by single parents and finds a first order partial correlation of .06. Which of the following correctly describes the outcome? This is a ______ relationship

spurious

The partial correlation coefficient between X and Y after controlling for Z shows a much weaker relationship than the Pearson's r computed for X and Y. This would be taken as evidence of a ________ relationship between X and Y

spurious or intervening

Measure of Association if the value is greater than .60

strong

For variables measured at the ordinal level gamma measures

symmetrical PRE measure of association

William Gosset discovered...

t-distribution

In regression analysis the symbol "a" stands for...

the Y intercept

The alternative research hypothesis for the ANOVA test is __________________________.

the means are not all equal

In most correlation matrices, the diagonal line has a value of

1

A researcher has found a strong relationship between level of education and income and concludes that "higher levels of

By itself, association does not prove causation.

Which of the following is NOT true when computing phi? a.it is appropriate for 2 x 2 tables b.it is based on chi-square c.it is an example of PRE measure d.it is a measure of association for nominal variables

C. it is an example of PRE measure

EPSEM Sampling

Equal Probability of Selection Method NOT SNOWBALLING SAMPLING

An obtained chi square of 2.78 has been calculated critical chi square is 3.841. What should be concluded?

Fail to reject the null, variables are independent (the obtained score is lower than the critical)

A researcher has analyzed differences in average College Board scores for random samples of students from four different colleges. The obtained F score is .45 and the critical F score is 3.65. What can be concluded about the null hypothesis?

Fail to reject, the differences are not statistically significant

ANOVA output from SPSS: Is the result significant?

If F(obtained) exceeds the F(critical) we reject the null, meaning it is significant.

The relationship between measures of association and causal relations between variables may be summarized as

association doesn't prove causation

With two independent variables the least squares multiple regression equation would be

Y= a + b1X1 + b2X2

A one tailed hypothesis test is used when

a statistical test in which the critical area of a distribution is one-sided so that it is either greater than or less than a certain value, but not both. If the sample that is being tested falls into the one-sided critical area, the alternative hypothesis will be accepted instead of the null hypothesis. The one-tailed test gets its name from testing the area under one of the tails (sides) of a normal distribution, although the test can be used in other non-normal distributions as well.

A researcher is trying to determine if income(X1) or number of friends (X2) is more important in determining personal happiness (Y). Which of the following would be the most profitable course of action? a. Examine the standardized partial slopes of X1 and X2 on Y. b. Examine the unstandardized partial slopes of X1 and X2 on Y. c. Compute the partial correlation coefficient for X1 and X2 controlling for Y. d. Examine the partial slope of Y on each independent separately.

a. Examine the standardized partial slopes of X1 and X2 on Y.

After controlling for Z a researcher finds evidence of a spurious relationship between X and Y. What step should be taken next? a. Z should become the new independent variable. b. Z should become the new dependent variable. c. Z should be disregarded and a new control variable should be selected. d. Z should be disregarded and a new independent variable should be selected.

a. Z should become the new independent variable.

After controlling for Z, the partial correlation coefficient between X and Y is the same value as the bivariate Pearson's r. This pattern would be taken as evidence of a. a direct relationship between X and Y. b. a spurious relationship between X and Z. c. interaction between X, Y, and Z. d. an intervening relationship between X and Y, interaction between X and Z.

a. a direct relationship between X and Y.

An analysis of the relationship between income and education found a correlation of .43. After controlling for age, the partial correlation was .43. The relationship between income and education seems to be a. direct b. spurious c. intervening d. interactive

a. direct

A gamma computed on the relationship between marital happiness and amount of TV viewing is +.78. This means that a. if we know how pairs of couples compare on TV viewing, we would be 78% better off predicting their ranks on marital happiness. b. happily married couples don't watch TV. c. couples that watch a lot of TV tend to be unhappy. d. TV causes divorce.

a. if we know how pairs of couples compare on TV viewing, we would be 78% better off predicting their ranks on marital happiness.

The direction of a relationship between variables can be detected on a scatterplot by considering the angle of the regression line. The relationship is... a. positive when the line slopes upward from left to right. b. positive when the line slopes downward from left to right. c. negative when the line slopes upward from left to right. d. negative when the line slopes downward from right to left.

a. positive when the line slopes upward from left to right.

The F ratio is a ratio of _____________________ to ______________________.

amount of variation between categories to amount of variation within categories

Which of the following must be normally distributed in order to proceed with hypothesis testing of means and proportions? a. the sample distribution b. the sampling distribution c. the population distribution d. both the sample distribution and the population distribution

b. the sampling distribution

If the regression line showing the effect of education on income has a slope of 1000, a. the variables are not related. b. every year of education increases income by 1000. c. every change in education increases income. d. the Y intercept would be 1.00.

b. every year of education increases income by 1000.

If we fail to reject the null hypothesis in a test of significance for a Pearson's r we conclude that a. there is a negative association between the variables b. no inference can be made about the relationship of the two variables in the population c. the relationship exists but its direction and strength and unknown d. variables are related in the population

b. no inference can be made about the relationship of the two variables in the population

If the beta weight of the first independent (X1) is .45 and the beta weight of the second independent (X2) IS -.5 then A. X1 has a stronger direct effect than X2. B. X2 has a stronger direct effect than X1. C. Y2 must equal zero. D. the multiple correlation coefficient must be negative.

beta weights are another name for standardized slopes, so you would look for the bigger number to tell you which one has a stronger effect on the dependent variable. In this case, -.5 is bigger than .45, so X2 has a stronger effect than X1. Answer choice:B

A researcher is examining the effects of income(X1) and number of friends(X2) on personal happiness and finds an R^2 of .45. Which of the following is a correct interpretation of this result? a. Money CAN buy happiness. b. Friends are more important than money for happiness. c. Taken together, income and number of friends explain 45% of the variance in happiness. d. Taken together, income and number of friends explain 0.45% of the variance in happiness.

c. Taken together, income and number of friends explain 45% of the variance in happiness.

A study of traffic safety shows a correlation of 0.57 between average speed of traffic and number of fatal accidents for a particular stretch of highway. This means that a. drivers should speed up to get through this area as quickly as possible. b. as speed increases, fatalities decrease. c. fatalities tend to increase as average speed increases. d. every 1 mile per hour increase in average speed increases the number of traffic fatalities by .57.

c. fatalities tend to increase as average speed increases.

Gamma will be zero if... a. the variables are strongly related b. the relationship is negative c. knowledge of the IV does not improve our ability to predict the dependent variable d. the scores of each case are symmetrical to the scores of all other cases

c. knowledge of the IV does not improve our ability to predict the dependent variable

The positive of the least-squares regression line is defined by two elements: a. the X intercept and the slope of the line. b. the X intercept and the Y intercept. c. the Y intercept and the slope of the line. d. the intersection point of the X and Y axes and the slope of the line.

c. the Y intercept and the slope of the line.

In the multiple regression equation the unstandardized partial slopes show a. the point where the line crosses the Y axis. b. the combined effects of all independents on the dependent variable. c. the amount of change in Y for a unit change in one independent variable while controlling for all other independent variables. d. the residual effects of the independent after partialling out the effect of the dependent variable.

c. the amount of change in Y for a unit change in one independent variable while controlling for all other independent variables.

Dummy variables make it possible to include ______________ in regression analysis.

categorical variables

A researcher wants to measure the strength of the association between income (measured in dollars per year) and education (measured in number of years of formal schooling). Which of the following would be the most appropriate measure of association? a. the slope (b) b. gamma c. chi square d. Pearson's r

d. Pearson's r

If you wanted to measure the association between the age of people (in years) and the number of arrests for driving while a. gamma. b. lambda. c. phi. d. Pearson's r.

d. Pearson's r

Partial and multiple correlation are based on a. bivariate tables b. chi-square statistics c. the analysis of variance d. Pearson's r

d. Pearson's r

Partial and multiple correlation require data which are a. nominal and continuous b. ordinal and discrete c. inferential and bivariate d. interval-ratio

d. interval ratio

Which of the following is not a prerequisite for the use of the techniques of multiple regression and correlation? a. interval ratio level of measurement b. linear relationships c. no interactions among the variables d. partial slopes less than zero

d. partial slopes less than zero

In the ANOVA test the symbol 'dfb' refers to

degrees of freedom associated with SSB

In the ANOVA test the symbol 'dfw' refers to...

degrees of freedom associated with SSW

The population variance is a measure of ____________________.

dispersion

If there is no association between two variables, knowledge of the independent variable

does not change the number of errors of prediction

One limitation of ANOVA is that when the null hypothesis is rejected the test...

doesn't tell us which sample means are different

The techniques of multiple correlation and regression can be used as long as

every variable is measured at the interval-ratio level (you can also include a nominal variable if you transform it into a dummy variable). Other criteria: the independent variables must NOT be correlated with one another, and each independent variable must be linearly related with the dependent variable.

A researcher is interested in the relationship between social class (measured as upper middle or lower) and support (measured as strong, moderate, or weak) for a program of welfare reform. An appropriate measure of association for these two variables would be...

gamma

The central limit theorem states

given a sufficiently large sample size from a population with a finite level of variance, the mean of all samples from the same population will be approximately equal to the mean of the population. "the more values you get, you will be closer to the mean"

In hypothesis testing you can reject the null hypothesis whenever the observed test statistic is ____ than the critical test statistic, as well as whenever the p-value _____ is than the alpha value (which is normally .05)

higher; lower

In the chi square test of hypothesis the null hypothesis states that the variables are ....

independent

The ANOVA test is designed for dependent variables that have been measured at__________.

interval ratio level

For the relationship involving education and library use gamma was +.37 this indicates that

library use increases with education

When the null hypothesis in the chi square test for independence is true there should be..

little difference between observed frequency and the expected frequency

inferential statistics

make judgments of the probability that an observed difference between groups is a dependable one or one that might have happened by chance in this study.

The subtotals calculated for bivariate tables are also known as....

marginals

Test of significance tell us if our results are non-random. To investigate the strength and direction of relationship, we must use...

measures of association

The regression line is a line that a. minimizes the squared residuals b. equals the average of all the scores c. connects the lowest score to the highest score d. is always parallel to the horizontal axis

minimizes the squared residuals

Measure of Association if the value is between .31 and .60

moderate

In multivariate regression you have

multiple independent variables and multiple dependent variables

In the Chi square test, expected frequencies are computed by

multiplying the proper row and column marginals for each cell and dividing by N

As one variable increases and the other variable decreases this is an example of...

negative relationship

Lambda is a PRE measure that is used when variables are measured at the...

nominal level

Phi and Cramer's V would be appropriate as measures of association for variables measured at the...

nominal level

To prove that one variable causes another, we use

none of the above, neither measures can prove casual relationships

Gamma is an appropriate measure of association for ...

ordinal level

For the relationship between social class and movie attendance, a researcher found a gamma of -0.45. This indicates that a. as social class increases, so does movie attendance. b. rich people watch more movies than poor people. c. there is no relationship between these variables. d. people from higher social classes are less likely to attend movies.

people from higher social classes are less likely to attend movies.

As one variable increases and the other variable increases this is an example of...

positive relationship

In an ANOVA test when the null hypothesis is rejected, we know that at least one of the means is significantly different from the others. In order to find out which means are significantly different we must conduct a...

post hoc

The two quantities needed to calculate lambda are prediction errors using the independent variables and

prediction errors ignoring the independent variable

According to the logic of proportional reduction of error (PRE), if two variables are associated then information about the independent variable...

reduces the number of errors in predicting the dependent variable

If our F (obtained) exceeds F (critical), we

reject the null

A Chi square test has been conducted to assess the relationship between marital status and church attendance. The obtained Chi square is 23.45 and the critical Chi square is 9.488. What may be concluded?

reject the null, variables are dependent

If we fail to reject the null hypothesis in a test using analysis of variance, we are concluding that...

the population from which our samples come are similar

If we reject the null hypothesis in a test using analysis of variance we are concluding that...

the populations from which our samples come are different

in the context of chi square variables are independent if...

the score of a case on one variable has no effect on the score of the case on the other variable

Stated generally, the null hypothesis for the ANOVA test is

u1=u2=u3=...=uk

In a research study conducted to determine if arrests were related to the socioeconomic class of the offender, the chi square

variables are dependent

In the Chi square test for independence the alternative research hypothesis is...

variables are dependent

In the Chi square test for independence the null hypothesis and the research hypothesis...

variables are independent

Measure of Association if the value is between .00 and .30

weak

Lambda is an asymmetric measure, meaning it ________.

will change value depending on which variable is dependent and which is independent

The ANOVA test uses means and standard deviations to compare the amount of variation ____________________ with the amount of variation _____________________.

within categories; between categories