Statistics 2.1 - (Variables and Data)

Variable

A characteristic that varies from one person or thing to another

Qualitative variable

A non-numerically valued variable

Quantitative variable

A numerically valued variable

Discrete variable

A quantitative variable whose possible values can be listed, even though the list may continue indefinitely.

Continuous variable

A quantitative variable whose possible values form some interval of numbers, such as a height of a person

Data

The values of a variable for one or more people or things (information collected, organized, and analyzed)

Data classifications

Qualitative data, quantitative data, discrete data, and continuous data

Observation

Each individual piece of data

Data set

Collection of all observations for a particular variable

Quantitative data

Numbers representing counts or measurements

Qualitative (categorical or attribute) data

Can be separated into different categories that are distinguished by some nonnumeric characteristics

Discrete

Data result when the number of possible values is either a finite number or a ‘countable’ number of possible values (0, 1, 2, 3, 4…)

Continuous

Numerical; data result from infinitely many possible values that correspond to some continuous scale or interval that covers a range of values without gaps, interruptions, or jumps

Sample

Select a portion of a population

Population

Selection of all members

Statistics

Method used to collect, analyze, present, and interpret data to make decisions

Variable

Characteristic being investigated