Chapter 10 - Hypothesis Testing (Categorical Data) Flashcards Preview

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Flashcards in Chapter 10 - Hypothesis Testing (Categorical Data) Deck (8)
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1
Q

Categorical data

A
  • discrete data require inference too
  • we will strictly focus on categorical data that can be assumed to have an underlying binomial distribution
  • our goal is to infer about parameter p
2
Q

Contingency table method

A
  • a 2 x 2 contingency table is a table composed of two rows cross-classified by two columns
  • displays data that can be classified by two different variables, each of which has only two possible outcomes
3
Q

Contingency table - types of tests

A
  • test for homogeneity of binomial proportions

- test of independence or a test of association

4
Q

Test for homogeneity of binomial proportions

A
  • tests whether the proportions are the same in two independent samples
5
Q

Test of independence or a test of association

A
  • tests whether there is some association between two reported measures of a characteristic
6
Q

Contingency tables - the cells

A
  • (1,1)
  • (1, 2) = first row, second column
  • (2, 1) = second row, first column
  • (2,2)
7
Q

Contingency tables - presentation of totals

A
  • the number of units in each row are displayed in the right margins, which are called row marginal totals, or row margins
  • the number of units in each column are displayed in the bottom margins, which are called column marginal totals, or column margins
  • the total number of units in the four cells, which is displayed in the lower-right hand corner of the table, is called the grand total
8
Q

Chi-square test statistics

A
  • if there are large difference between observed and expected values then that provides evidence against H0
  • this is referred to as the Pearson chi-square test statistic as it has a chi-square distribution with 1 df