stats comp review

Question 1

What is a p-value?

Answer 1

the probability of obtaining the data (or the data showing as great or greater difference from the null hypothesis) if the null hypothesis were true

Question 2

What is sampling distribution?

Answer 2

the probability distribution of all values for an estimate that we might obtain when we sample a population

Question 3

What is the standard error of an estimate?

Answer 3

the standard deviation of the estimates sampling distribution

Question 4

The standard error of an estimate is an estimate of what?

Answer 4

the precision of the statistic in question

Question 5

What can standard error be calculated for?

Answer 5

Precision, median, correlation, difference between means

Question 6

What is variance

Answer 6

a measure of spread with useful mathematic properties

Question 7

What is standard deviation?

Answer 7

commonly used measure of the spread that measures how far from the mean the observations typically are

Question 8

What is standard deviation the square root of?

Answer 8

Variance

Question 9

What is Akaike Information Criterion (AIC)?

Answer 9

a mathematical method for evaluating how well a model fits the data it was generated from

Question 10

What is AIC used for?

Answer 10

comparing different models and determining which one is the best fit for the data

Question 11

What is AIC calculated from?

Answer 11

The number of independent variables used to calculate the model-the maximum likelihood estimate of the model (how well the model reproduces the data)

Question 12

What is the best fit model according to AIC?

Answer 12

the one that explains the greatest amount of variance using the fewest possible independent variables

Question 13

What is the significance level?

Answer 13

a probability used as a criterion for rejecting the null hypothesis

Question 14

What happens if your p-value is less than alpha?

Answer 14

reject the null hypothesis

Question 15

What happens if your p-value is greater than alpha?

Answer 15

fail to reject the null hypothesis

Question 16

What is type I error?

Answer 16

rejecting a true null hypothesis

Question 17

What is type II error?

Answer 17

failing to reject a false null hypothesis

Question 18

What is a test statistic?

Answer 18

a number calculated from the data that is used to evaluate how compatible the data are with the result expected under the null hypothesis

Question 19

Is the p-value a test statistic?

Answer 19

No, the test statistic is compared to the null distribution in calculating a p-value

Question 20

What is the null distribution?

Answer 20

The sampling distribution of outcomes for a test statistic under the assumption that the null distribution is true

Question 21

How can we get different values under the null hypothesis in regards to the null distribution?

Answer 21

Sampling error