# contingency tables

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Category: Education

## Presentation Description

How to construct a two-by-two contingency table for cross tabulation.

## Presentation Transcript

### Two-by-Two :

Two-by-Two Contingency Table

### Rules: each case :

Rules: each case must go into a cell

### Rules: each case :

Rules: each case must go into a cell can only go into one cell

### Separate Groups :

Separate Groups Rows for I.V. or predictor

### Separate Groups :

Separate Groups Rows for I.V. or predictor: Male vs. Female

### Separate Groups :

Separate Groups Rows for I.V. or predictor: Male vs. Female Pass vs. Fail

### Separate Groups :

Separate Groups Rows for I.V. or predictor Columns for D.V. or criterion

### Separate Groups :

Separate Groups Rows for I.V. or predictor Columns for D.V. or criterion Vote YES or NO

### Separate Groups :

Separate Groups Rows for I.V. or predictor Columns for D.V. or criterion Vote YES or NO PASS or FAIL test

### What percent of :

What percent of The experimental group passed?

### What percent of :

What percent of The experimental group passed? 100 X A/(A+C)

### What percent of :

What percent of The experimental group passed? 100 X A/(A+B) 100 X 15/20 = 75%

### What percent of :

What percent of The control group passed?

### What percent of :

What percent of The control group passed? 100 X C / (C+D)

### What percent of :

What percent of The control group passed? 100 X C / (C+D) 100 X10 / 30 = 33%

### Repeated Measures :

Repeated Measures Two raters Two times

### Repeated Measures :

Repeated Measures Two raters Interviewers Quality judges

### Repeated Measures :

Repeated Measures Two raters Two times Before vs. After

### What percent of :

What percent of Cases had it the first time?

### What percent of :

What percent of Cases had it the first time? 100 X A / (A+C)

### What percent of :

What percent of Cases had it the first time? 100 X A / (A+C) 100 X 8/10 = 80%

### What percent of :

What percent of Cases had it the second time?

### What percent of :

What percent of Cases had it the second time? 100 X A / (A+C)

### What percent of :

What percent of Cases had it the second time? 100 X A / (A+C) 100 X 8/15 = 53%

### Two-by-Two :

Two-by-Two Contingency Table