chapter 7 (hypothesis testing)

Question 1

hypothesis testing

Answer 1

statistical tests that estimate the probability of sample outcomes if assumptions about the population (null hypothesis) are true.

Question 2

five-step model

Answer 2

step-by-step guideline for conducting tests of hypotheses. framework that organizes decisions and computations for all tests of significance.
1. make assumptions and meet test requirements. (need srs.)
2. state null hypothesis. (in form of equation. usually state research hypothesis too.)
3. select sampling distribution and establish critical region. (size of critical region reported as alpha level.)
4. compute test statistic.
5. make a decision and interpret the results of the test.

Question 3

null hypothesis (H0)

Answer 3

statement of no difference/relationship. in context of chi square, variables are assumed to be independent in population.

Question 4

research hypothesis (H1)

Answer 4

statement the contradicts the null hypothesis. in context of chi square, research hypothesis says variables are dependent in population.

Question 5

alpha level

Answer 5

proportion of area under sampling distribution that contains unlikely sample outcomes, given that null hypothesis is true. also probability of type I error. associated with critical statistic score.

Question 6

critical value

Answer 6

point in sampling distribution that is compared to test statistic (obtained score) to decide if null hypothesis should be rejected,

Question 7

p value

Answer 7

area under sampling distribution that indicates the exact likelihood of rejecting the null hypothesis when it is true (risk of type 1 error.) associated with test (obtained) statistic.

Question 8

type I (alpha) error

Answer 8

probability of rejecting a null hypothesis that is true.

Question 9

type II (beta) error

Answer 9

probability of failing to reject a null hypothesis when it is false.

Question 10

chi square test

Answer 10

non-parametric test of hypothesis for variables that are organized in a bivariate table.

Question 11

non-parametric

Answer 11

“distribution-free.” refers to tests that do not assume a normal sampling distribution. (ex: chi square.)

Question 12

bivariate tables

Answer 12

table that displays the joint frequency distributions of two variables.

Question 13

rows

Answer 13

horizontal dimension of bivariate table. represents score for dependent variable.

Question 14

columns

Answer 14

vertical dimension of a bivariate table. represents score for independent variable.

Question 15

cells

Answer 15

cross-classification categories of variables in a bivariate table.

Question 16

marginals

Answer 16

the row and column subtotals in a bivariate table.

Question 17

independence

Answer 17

null hypothesis in chi square test. two variables are independent if, for all cases, the classification of a case on one variable has no effect on the probability that the case will be classified in any particular category of the second variable. the variables do not affect each other.

Question 18

expected frequencies

Answer 18

cell frequencies that would be expected in a bivariate table if the variables were independent.