Five w's of data

Who*, What*, Why*, When, Where

The who is the ________ the study is about.

Individual

Other words that may be used for the who are:

The characteristics of interest about the individual are called ________.

variables

Data that can be placed into categories, but cannot be averaged.

Categorial Variables

Variables recorded in numbers and used as numbers, which can be averaged.

Quantitative Variables/Numerical Data

C or Q: The number of calories in a fast food sandwich.

Quantitative

C or Q: Whether an American household owns a cat or does not own a cat.

Categorical

C or Q: The occupational background of a Civil War general.

Categorical

C or Q: The airfare to a selected city from Baltimore.

Quantitative

C or Q: The age of a bride on her wedding day.

Quantitative

A _______ ______ organizes the data by giving the counts for each category.

Frequency Table

A _________ ___________ ________ gives the percentages for each category rather than the counts.

Relative Frequency Table

A ____ _______ displays the distribution of a categorial variable, showing the counts for each category next to each other for easy comparison.

Bar graph/chart

A ____ ______ is a display where a circle is sliced into pieces whose size is proportional to the fraction of the whole in each category.

Pie chart

A display used when we look at 2 categorical variables together. These are often called two-way tables.

Contingency Table

This is a distribution of one of the variables. These are the counts or percentages found in the last row or column of the table or margins.

Marginal Distribution

This is a distribution of one variable only for those individuals satisfying a given condition.

Conditional Distribution

In a contingency table, when the distribution of one variable is the same for all categories of another, then the variables are said to be _____________.

Independent

A contingency table can also be used to create a graph such as a _________ _____ ______. In this graph each bar is a whole and is divided proportionally based on the conditional distributions for each variable.

Segmented bar chart

The area occupied by a part of the graph should correspond to the magnitude of the value it represents.

Area Principle

Averages that can be misleading.

Simpson's Paradox