Introduction to Statistics: Key Concepts and Data Types

These vocabulary flashcards cover fundamental statistical terms, variable types, and data visualization methods discussed in the lecture.

Population

The whole group that a researcher wants to gather information about.

Parameter

A value that describes a characteristic of a whole population.

Sample

A subset of a population from which researchers draw information.

Statistic

Information or data drawn specifically from a sample rather than the whole population.

Individuals

The objects or subjects (living or inanimate) from which information is being collected.

Variable

The specific characteristic or attribute of interest that changes from one individual to another, often represented by $x$ or $y$.

Qualitative Variable

Also known as a categorical variable, it is a type of data that places each individual into a specific category based on a non-numerical characteristic.

Likert Scale

A measurement tool (e.g., rating poor to great as $1$ to $5$) that uses numbers to represent categories, making it a qualitative rather than quantitative variable.

Quantitative Variable

A variable that takes on numerical values for which arithmetic operations make sense.

Discrete Data

A type of quantitative data where there are only a finite number of possible values or visible gaps between possible values on a number line.

Continuous Data

A type of quantitative data where values can take on any possible value within a finite or infinite interval, meaning there are no gaps between values.

Distribution of a Variable

A description that identifies what values a variable takes on and how often it takes those specific values.

Frequency Table

A table used to record the number of times a certain value or category occurs within a data set.

Relative Frequency Table

A table that displays the proportion or percentage of the total data set that falls into each category, often represented as a decimal or a value out of $100\%$.

Pie Chart

A graph used for qualitative variables that shows how a whole is divided into different categories based on their proportions.

Bar Graph

A graphical display for qualitative data that uses rectangles of varying heights to represent frequencies or relative frequencies of categories.

Histogram

A diagram for quantitative variables that uses adjacent rectangles to show the frequency of data within specific numerical ranges, known as bins.

Bins

The ranges of values appearing on the horizontal axis of a histogram that group quantitative data together.

Stem Plot

Also known as a stem-and-leaf plot, this is a graphical tool for quantitative data that organizes values to show the shape of the distribution.