# Discovering Statistics; Chapter 2 Flashcards

1
Q

Why do we build statistical models of the real world?

A

In an attempt to predict how these processes operate under certain conditions. We can only make inferences based on models.

2
Q

What is the fit?

A

Degree to which data fits the model.

3
Q

What is the population?

A

The group of people the sample has been taken from.

4
Q

What is the sample?

A

The smaller group of people to be tested, taken from the population.

5
Q

What is the standard error?

A

The standard deviation of sample means, therefore is a measure of how representative a sample is likely to be of a population.

6
Q

What is the alternate hypothesis?

A

Denoted as H1, states there will be a correlation.

7
Q

What is the null hypothesis?

A

Denoted as H0, states there will not a correlation. We are always trying to disprove the null hypothesis.

8
Q

What is the test statistic?

A

The ratio of systematic:unsystematic variation.

9
Q

What is the familywise/experimental error rate?

A

The error rate across statistical tests conducted on the same data.

10
Q

What is the statistical power?

A

The ability of a test to find an effect.

11
Q

What is null hypothesis significance testing?

A

We test the significance of the NULL hypothesis. A non-significant result doesn’t necessarily mean the null hypothesis is true. A significant response doesn’t necessarily mean the alternative experiment is true.

12
Q

What is Cohen’s d?

A

The difference between scores expressed in units of standard deviation.

13
Q

What is the correlation coefficient?

A

Measure of the strength of a relationship of two variables.

```r = .10 => small effect.
r = .30 => medium effect.
r = .50 => large effect.```
14
Q

What is a meta-analysis?

A

Combining multiple studies to get a definitive estimate for the population value.