Introduction to Statistics: Data, Variables, and Sampling Methods

Statistics

The science of conducting studies to collect, organize, summarize, analyze, and draw conclusions from data.

Data

The values or measurements that variables can assume.

Subjects

The people or objects included in the study; in this case, the employees being observed.

Variable

A characteristic of the subject that is measured or observed.

Distance Traveled

The distance traveled to work (in miles).

Primary Commute Method

The primary method of commuting (e.g., Car, Public Transit, Bike, Walk).

Quantitative Variable

A variable that takes numeric values that can be measured and are meaningful for mathematical operations.

Continuous Variable

A type of quantitative variable that can take any value within a range, including decimals and fractions.

Qualitative Variable

A variable that takes non-numeric values such as categories or labels.

Population

All subjects being studied; in this case, all employees of the large company.

Census

Data collected from every employee.

Sample

A group of subjects selected from the population.

Population Parameter

A numerical measure that describes an aspect of the population.

Sample Statistic

A numerical measure that describes an aspect of a sample.

Ratio Level

A level of measurement that is rank-ordered, has equal intervals, and includes an absolute zero.

Nominal Level

A level of measurement that classifies values into categories where the categories are given names or labels.

Unbiased Sample

A sample where every individual in the population has an equal chance of being selected.

Stratified Sampling

A technique where the population is divided into distinct subgroups based on a characteristic, and a proportional number of subjects is randomly selected from each subgroup.

Experimental Study

A study where an intervention is used to measure the change in a variable.

Independent Variable

The presumed cause in an experimental study.

Dependent Variable

The measured outcome in an experimental study.