Question 1

Nonparametric tests are used when the independent variables are nonmetric.

Accepted Answer

Nonparametric tests do not require the data to be normally distributed or to have a specific type of relationship between variables. Therefore, they are suitable for nonmetric independent variables.

Question 2

The F static is computed as the ratio of two sample variances.

Accepted Answer

The F statistic is calculated as the ratio of two sample variances, specifically the variance of the means between the groups and the variance of the observations within the groups.

Question 3

The runs test tests the goodness of fit of the observed number of observations in each category to the number expected under specified binomial distribution.

Accepted Answer

The runs test is used to examine the randomness of a sequence by analyzing the occurrences of sequences of consecutive similar elements (runs), not to test the goodness of fit of observed frequencies to those expected under a binomial distribution.

Question 4

In hypothesis testing,the observations are paired so that the two sets of observations relate to the same respondents.

Accepted Answer

This statement is true. In paired sample hypothesis testing, the two sets of observations are obtained from the same individuals or objects, either before and after an intervention or under two different conditions. Examples of paired samples include pre-test and post-test data, measurements of the same variable on two different occasions, or measurements of two different variables taken from the same subject. Paired samples are often used in experimental and longitudinal research designs to control for individual differences and increase the power of statistical tests.

Question 5

Paired samples are two samples that are not experimentally related.

Accepted Answer

Paired samples are two samples that are experimentally related, such as before and after measurements or measurements from matched pairs.

Question 6

Hypothesis-testing procedures can be broadly classified as parameter or nonparameter based on the measurement scale of the variables involved.

Accepted Answer

The answer of Hypothesis-testing procedures can be broadly classified as...

Question 7

The McNemar test is another paired sample nonparametric test that is used in the special case of a binary variable where the researcher wishes to test differences in proportions.

Accepted Answer

The McNemar test is a paired sample nonparametric test used to test differences in proportions for binary variables.

Question 8

When measuring the strength of association with the contingency coefficient,the maximum value of 1 is achieved when the variables are perfectly associated.

Accepted Answer

The contingency coefficient is a measure of association between two categorical variables, but its maximum value is always less than 1, even when the variables are perfectly associated. This is because it is based on the chi-square statistic and adjusted for the sample size, leading to a maximum value that depends on the size of the contingency table but is always less than 1.

Question 9

The two-sample median test is not as powerful as the Mann-Whitney U test.

Accepted Answer

The Mann-Whitney U test is generally more powerful than the two-sample median test, meaning it is more likely to correctly detect a significant difference between two groups.

Question 10

The two-sample median test examines whether the two distributions are the same.

Accepted Answer

The two-sample median test specifically assesses whether the medians of two independent samples are different, not whether their entire distributions are the same.

Question 11

The critical value of the F distribution depends upon two sets of degrees of freedom: those in the numerator and those in the denominator.

Accepted Answer

This is true. The critical value of the F distribution is determined by the degrees of freedom in the numerator and the degrees of freedom in the denominator.

Question 12

When conducting cross-tabulation analysis in practice,if H₀ is rejected,the pattern of the relationship should be interpreted by computing an appropriate statistic (phi coefficient,contingency,Cramer's V,lambda coefficient,or other statistics).

Accepted Answer

The answer of When conducting cross-tabulation analysis in practice,if H₀...

Question 13

When variables are perfectly associated,the phi coefficient assumes the value of 1.

Accepted Answer

Phi coefficient measures the degree of association between two variables and ranges from -1 to 1. When variables are perfectly associated, the phi coefficient assumes the value of 1, indicating a strong positive association.

Question 14

The Mann-Whitney U test is a statistical test for a variable measured on an ordinal scale,comparing the difference in the location of two populations based on observations from two independent samples.

Accepted Answer

The explanation given in the statement is correct. The Mann-Whitney U test is a non-parametric test used to compare the medians of two independent samples, where the data are measured on an ordinal scale or have an underlying distribution that is not normal.

Question 15

The binomial test is a test of randomness for a dichotomous variable.

Accepted Answer

The binomial test is used to determine if the proportion of successes in a dichotomous variable is significantly different from a hypothesized proportion, not to test for randomness.

Question 16

The chi-square statistic can be estimated on counts of data or on percentages.

Accepted Answer

The chi-square statistic is calculated using observed and expected frequencies (counts), not percentages. Converting percentages to counts is necessary before using the chi-square test.

Question 17

An asymmetrical lambda value of 1 happens when each independent variable category is associated with a single category of the dependent variable.

Accepted Answer

This is correct. An asymmetrical lambda value of 1 means that each category of the independent variable is perfectly associated with a single category of the dependent variable.

Question 18

In the Mann-Whitney U test,two samples are combined and the cases are ranked in order of increasing size.The test statistic,U,is computed as the number of times a score from sample 1 or group 1 follows a score from group 2.

Accepted Answer

The Mann-Whitney U test statistic, U, is computed as the sum of the ranks for the observations from one of the groups, not by counting the number of times a score from one group follows a score from the other group.

Question 19

The Kolmogorov-Smirnov one-sample test is a goodness of fit test that compares the cumulative distribution function for a variable with a specified distribution.

Accepted Answer

The Kolmogorov-Smirnov one-sample test is a goodness of fit test that compares the cumulative distribution function for a variable with a specified distribution. Therefore, the statement in the question is true.

Question 20

Lambda assumes that the variables are measured on an ordinal scale.

Accepted Answer

Lambda is a measure of association used for variables measured on a nominal scale, not an ordinal scale.

Quiz 15: Frequency Distribution,cross-Tabulation,and Hypothesis Testing