Stats Metacog 4

Question 1

What is the consequence of making a Type I error?

Answer 1

Concluding the treatment has an effect when it truly does not

Question 2

T or F: a statistically significant treatment effect does not always indicate a large treatment effect

Answer 2

True

Question 3

T or F: if the power for a hypothesis test is .80, then the probability of committing a Type II error = .20

Answer 3

True

Question 4

What do you first use to calculate power?

Answer 4

Delta

Question 5

What is the equation for delta?

Answer 5

δ = 𝑑 × (square root of n/2)

Question 6

How do you interpret the delta?

Answer 6

Using the delta table

Question 7

How does the size of the sample effect delta?

Answer 7

As the sample size increases, so does the power

Question 8

What does a power table do?

Answer 8

Can be used in place of a delta table. You work backwards to figure out how large of an effect or sample size you would need for a given sig level

Question 9

When can you calculate power?

Answer 9

Before completing a study or after as a post hoc

Question 10

What is correlation?

Answer 10

Correlation is the measure of how related two things are to one another

Question 11

What are other names for Pearson’s correlation coefficient?

Answer 11

Pearson’s r, Pearson’s p, Bivariate correlation, r, or p

Question 12

What does Pearson’s r measure?

Answer 12

measures the linear relationship between two continuous variables (X and Y). It also describes the strength of the relationship

Question 13

What is the range of r?

Answer 13

• Ranges from -1 to +1

Question 14

What does a + r represent?

Answer 14

A positive relationship between X and Y

Question 15

What does a - r represent?

Answer 15

A negative relationship between X and Y

Question 16

What does a scatterplot do?

Answer 16

It allows us to plot both X and Y at the same time

Question 17

T or F: Scatterplots can be in different scales

Answer 17

True

Question 18

What are we able to do if there is a stronger relationship between X and Y?

Answer 18

We are better able to guess or predict a value knowing the other

Question 19

In what situations does r not work well?

Answer 19

• Nonlinear data
• When variation in one variable increases as the other variable changes values
• Skewed data
• When the data has outliers

Question 20

What are the steps to calculate Pearson’s r?

Answer 20

1. Make a new XY variable
2. calculate the mean of X, Y, and XY
3. Calculate the sum of X, Y, and XY
4. Calculate the SS for X and Y
5. Solve for Rxy (using the formula)

Question 21

What will a strong relationship look like?

Answer 21

Data points that are close together without a lot of variation

Question 22

What can correlations help us do?

Answer 22

Allows us to predict where a data point will lie to a certain extent