Chapter 3: Analyzing Two-Variable Data

Front

What is a response variable?

Back

A response variable measures an outcome of a study.

Front

What is an explanatory variable?

Back

An explanatory variable may help predict or explain changes in a response variable.

Front

Can explanatory and response variables be categorical or quantitative?

Back

Yes, explanatory and response variables can be either categorical or quantitative.

Front

What does it mean if two variables have an association?

Back

Two variables have an association if knowing the value of one variable helps us predict the value of the other.

Front

Does association imply causation?

Back

No, association does not imply causation.

Front

What is a segmented bar chart?

Back

A segmented bar chart displays the possible values of a categorical variable as segments of a rectangle, with the area of each segment proportional to the percent of individuals in the corresponding category.

Front

What is a scatterplot?

Back

A scatterplot shows the relationship between two quantitative variables measured on the same individuals, with one variable on the horizontal axis and the other on the vertical axis.

Front

How do you describe a scatterplot?

Back

Describe a scatterplot by looking for the overall pattern and for striking departures from that pattern, including direction, form, and strength of the relationship.

Front

What is an outlier in a scatterplot?

Back

An outlier is an individual value that falls outside the overall pattern of the relationship.

Front

What is correlation?

Back

Correlation is a measure of the strength and direction of a linear relationship between two quantitative variables, taking values between −1 and 1.