# Discovering Statistics; Chapter 2 Flashcards

Why do we build statistical models of the real world?

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

What is the fit?

Degree to which data fits the model.

What is the population?

The group of people the sample has been taken from.

What is the sample?

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

What is the standard error?

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

What is the alternate hypothesis?

Denoted as H1, states there will be a correlation.

What is the null hypothesis?

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

What is the test statistic?

The ratio of systematic:unsystematic variation.

What is the familywise/experimental error rate?

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

What is the statistical power?

The ability of a test to find an effect.

What is null hypothesis significance testing?

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.

What is Cohen’s d?

The difference between scores expressed in units of standard deviation.

What is the correlation coefficient?

Measure of the strength of a relationship of two variables.

r = .10 => small effect. r = .30 => medium effect. r = .50 => large effect.

What is a meta-analysis?

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