Show:
Correlation
Regression
Chi-Square
Effect Sizes
Formulas
100

What kind of data do you need to run a correlation?

Interval or ratio.

100

What kind of data do you need to run a regression?

Interval or ratio.

100

What kind of data do you need to run a chi-square?

Nominal or ordinal

100

What is our effect size measure for a correlation?

The correlation itself (r).

100

Name this equation: y-hat = a + bx


Linear regression equation – the equation for a straight line.

200

What is Pearson’s r?

Correlational coefficient

• Measure of the linear association between variables (the extent the plotted data form a straight line).

200

Why would you use a regression instead of a correlation?

Varies.

⚠️ • Consider: Is there a difference between causation and correlation?

200

What is dependence in a chi-square? 


What is independence in a chi-square?

Dependence: Two variables are related.

Independence: Two variables are unrelated.

200

What is our effect size measure for a regression

Coefficient of determination (R2; R-squared).

200

How do you calculate degrees of freedom for a correlation?

df = n - 2

300

What is a positive correlation? What is a negative correlation?

As one variable increases, the other increases; as one variable increases, the other decreases.

300

In a regression, what do we call the IV? The DV?

X and Y

300

What can you use a chi-square test to determine?

If there is an association between variables 

300

What is our effect size measure for a chi-square?

Cramer’s V.

300

What is b in the following regression equation: y-hat = a + bx

The slope of the line

  • The value of b is interpreted as: increase in y for every unit increase in x).
400

What two pieces of information does the correlation coefficient provide?

1.) Strength (i.e., magnitude) of the relationship 

2.) Direction of the relationship 

400

True or False: You can only have one predictor in a regression.

❌ False.

400

True or False: We can compute means and standard deviations with chi-square tests.

❌ False.

• Why?

400

What is the coefficient of determination if r = .3?

It’s r-squared so it is...

• R2 = .09.

400

What is a in the following regression equation: 

y-hat = a + bx

The y-intercept.

  • Value when x = 0.
500

What does a correlation of 0 mean?

There is no LINEAR relationship between variables. (But there could still be a nonlinear relationship.)

500

Can you ever include a categorical variable in a regression? If so, how?

Dummy code

500

The rows and columns in an observed frequency matrix should sum to the _____.

Sample size (n)

500

If we have a Cramer’s V of .4, we have a _____ effect.


Medium.

Cramer's V Thresholds:

• Small = 0.1

• Medium = 0.3

• Large = 0.5

500

The formula for Pearson’s r is comprised of _____ and _____.


1.) Variances

2.) Covariances