PSY 3801

What are the two main uses of statistics in research?

Estimates, hypothesis testing, and prediction.

Define Descriptive Statistics.

Descriptive statistics allow us to describe patterns seen in the data we have.

What is the difference between a sample and a population?

A sample is drawn from a population, while a population includes all individuals of interest.

What is a Parameter?

A parameter is a measure that describes a population, often denoted by Greek letters.

What is the role of Extraneous Variables in research?

Extraneous variables are other variables that may affect the response variable but are not of primary interest.

What are Confounding Variables?

Confounding variables are extraneous variables that systematically vary with the explanatory variable, making it hard to determine their effect.

What is Measurement in research?

Measurement involves observing and recording values for a given variable, accounting for true levels and errors.

What defines a Nominal Scale of Measurement?

A nominal scale consists of categories that have no order or quantitative distinctions.

Provide an example of an Ordinal Scale of Measurement.

Clothing sizes or Amazon star ratings.

What characterizes an Interval Scale of Measurement?

An interval scale has ordered categories with equal intervals but no meaningful zero.

Give an example of a Ratio Scale of Measurement.

Reaction time or gain in height since last year.

What is a potential source of error when measuring stress levels with a questionnaire?

The wording of the question.

What level of measurement do letter grades represent?

Ordinal level of measurement.

What factors influence our inferences when taking samples?

Sample size, who is in the sample, study design, and the presence of extraneous or confounding variables.