General Stats and Odds Ratios

Question 1

What are some common types of analysis?

Answer 1

Univariate statistics
Bivariate statistics
Multivariate statistics

Question 2

What are univariate statistics?

Answer 2

• Frequency
• Mean
• Median
• Mode
• Standard deviation, etc.

Question 3

What are bivariate statistics?

Answer 3

Relationship between 2 variables. Chi-square, Pearson’s correlation (r), t-test.

Question 4

What are multivariate statistics?

Answer 4

Relationships among more than 2 variables

Question 5

What are the four main Scales of Measurement?

Answer 5

NOIR
Nominal
Ordinal
Interval
Ratio

Question 6

What are nominal measurements?

Answer 6

Measures mere differences (ex. hometowns, gender)

Question 7

What are ordinal measurements?

Answer 7

Measures differences + rank order (ex. place finish in a race; SES [working class, middle class, etc.], religiosity)

Question 8

What are interval measurements?

Answer 8

Measures differences + rank order + equal distances between values of the variable (ex. IQ - few examples of these non-meaningful zero values)

Question 9

What are ratio measurements?

Answer 9

Measures differences + rank order + equal distances between values of the variable + true, meaningful zero point (ex. income)

Question 10

What two Scales of Measurement are categorical/dichotamous?

Answer 10

Nominal, Ordinal

Question 11

What two Scales of Measurement are continuous?

Answer 11

Interval, Ratio

Question 12

What is the definition and examples of Nominal?

Answer 12

2 or more categories/groups; measures differences

ex: eye color, city of birth

Question 13

What is the definition and examples of Ordinal?

Answer 13

2 or more categories/groups with order/rank; measures differences + order
(ex: place finished in a race, SES status)

Question 14

What is the definition and examples of Interval?

Answer 14

Numerical value measured on a continuum; measures differences + order + equal units of measurement
(ex: temperature, IQ)

Question 15

What is the definition and examples of Ratio?

Answer 15

Numerical value measured on a continuum; measures differences + order + equal units of measurement + true/absolute zero point
(ex: height, weight)

Question 16

What things should you keep in mind with Scales of Measurement?

Answer 16

• How we measure phenomena is a choice (ex: race, gender)
• Technically, the statistical test you run depends on: how your variables are measured, your research question
• It is common for researchers to break test & measurement rules

Question 17

What statistical test is used for nominal vs. nominal measurements?

Answer 17

Chi-squared

Question 18

What statistical test is used for Nominal (2 groups only) vs. Interval or Ratio?

Answer 18

t-test

Question 19

What statistical test is used for Nominal (2 or more groups, 1 IV only) vs. Interval or Ratio?

Answer 19

One way analysis of variance (F-test) - ANOVA

Question 20

What statistical test is used for Nominal (2 or more groups, 2 or more IV) vs. Interval or Ratio?

Answer 20

Factorial design analysis of variance (F-test)

Question 21

What statistical test is used for Ordinal/Interval/Ratio vs. Ordinal/Interval/Ratio?

Answer 21

Pearson Correlation Coefficient

Question 22

What is the most common stat you’ll see with categorical outcomes?

Answer 22

Chi-Square test and accompanying p-value

-Categorical = dichotomous outcomes = yes/no values (often as %’s)

Question 23

What are quantitative outcomes also called?

Answer 23

continuous variables

Question 24

What is an example of when you’d do a Chi-Square test?

Answer 24

Ex. comparison of the % of men vs % of women who are diagnosed with major depression
Ex. Comparison of freshman, sophomore, junior and senior UMD undergrads earning at least 1 “F” letter grade.

Question 25

When is a Chi-Square test significant?

Answer 25

When P-value significant data

Question 26

What does a t-test do?

Answer 26

Another way of comparing values. - Checking to see if means are significantly different - T-test designed to compare MEANS - mean values are generally generated for continuous values

Question 27

What is the Odds Ratio (OR)?

Answer 27

Measure of association between two variables (ex. an IV and a DV)

Question 28

What is another way of defining OR?

Answer 28

"Odds" that some outcome would occur in the presence of a predictor (IV) vs. absence of the predictor

Question 29

When are Odds Ratios often discussed within medicine?

Answer 29

Case-control studies | -Though they are approbate for all kinds of categorical data

Question 30

In many studies we don't actually know incidence data. What do we use to estimate relative risk in these cases?

Answer 30

Odds Ratio

Question 31

What does OR = 1 mean?

Answer 31

Exposure does not affect odds of outcome.

Question 32

What does OR > 1 mean?

Answer 32

Exposure associated with higher odds of outcome.

Question 33

What does OR

Answer 33

Exposure associated with lower odds of outcome.

Question 34

What is the equation for OR?

Answer 34

AD/BC

Question 35

What is A, B, C, and D?

Answer 35

``` A = Disease +, RF + B = Disease -. RF + C = Disease +, RF- D = Disease -, RF- ```