Flashcards in Chi-Square Statistics Deck (32):

1

## Data sets that are not contiguous. For example: Dead or alive, head injury or no head injury, cancer or no cancer, etc.

### Categorical Variables

2

## There is no mean,median, mode, or normal distribution for

### Categorical data

3

## Take on values that are names or labels

### Categorical Variables

4

##
Different categorical variables can be associated with

-Ex: Is there a difference between college students and medical students in the number of hours of sleep per week?

### Eachother

5

## Categories may be inherent in the data or created by the researchers from

### continuous data

6

## We may want to change the data into categories if the categories are more clinically meaningful, or if the data are

### Non-normally distributed

7

## What is the conventional data presentation for the associations between categorical variables?

### Contingency tables

8

## In a contingency table, all data is independent, meaning that each person fits into only

### 1 box

9

## What should we always do for contingency tables?

### Put totals outside of each row/column

10

## The appropriate statistic to use for categorical data

### Chi-Square test

11

## In the Chi-square test, we first want to establish categories and the determine the

### Frequency within each category

12

## Once we know the frequency within each category, we want to

### Formulate a model

13

## The last thing we want to do in our Chi square test is compare the normal to the expected to see if the categories are

### Independent

14

## The Chi squared test is written as

### χ^2

15

## Measure the observed frequencies and compares them to the expected

### Chi-squared test

16

## How do we calculate the expected values for each box on the contingency table?

### Expected value = (row total x column total) / grand total

17

## For the chi-squared test, if our calculated value of X^2 is GREATER than the critical value, we

### Reject the null hypothesis

18

## For the chi-squared test, if our calculated value of X^2 is LESS than the critical value, we

### Can not reject null hypothesis

19

## The Chi-squared test is not valid for a 2x2 contingency table with very small samples. In this case, we use a

### Fisher Exact Test

20

## In Chi-squared tests, we make the assumptions that the data are frequency data, there is an adequate sample size, and the measures are

### Independent of eachother

21

## The study of disease occurence in human populations

### Epidemiology

22

## Epidemiology also uses

### Contingency tables

23

## Follow two groups of people, some who are exposed to a factor

### Cohort studies

24

##
Look at people with and without the disease and determine whether or not they were exposed

-like i the bone mineral example

### Case-control studies

25

## Measures the odds of getting a disease, given an exposure, and compares that to the odds of getting the disease without it

### Case-control study

26

## For a case-control study, we use the

### Odds ratio (OR)

27

## When using the odds ratio, OR = 1 means

### No difference in odds of exposure

28

## When using the odds ratio, OR > 1 means

### The odds of getting the disease are increased w/ exposure

29

## When using the odds ratio, OR less than one

### The odds of getting the disease decrease w/ exposure

30

## If the 95% confidence interval contains 1, than there is

### No effect of the exposure

31

## Used when data is normally distributed, there are more than 2 groups, and each person can only fall into one of the groups (I.e. Married, divorced, single, etc.)

### One way ANOVA

32