Levels of Measurement and Frequency Distributions

Vocabulary flashcards covering key terms from Levels of Measurement and Frequency Distributions notes.

Descriptive Statistics

Statistics that organize and summarize data to describe its main features (center, spread, distribution) without inferring to a population.

Inferential Statistics

Statistics that use sample data to draw conclusions about a population.

Population

The entire group of observations of interest.

Sample

A subset of the population selected for study.

Parameter

A numerical characteristic of a population, typically denoted by Greek letters.

Statistic

A numerical characteristic of a sample, typically denoted by Latin/English letters.

Variable

A characteristic that can take on different values.

Quantitative Variable

A variable that represents an amount or quantity.

Qualitative Variable

A variable that represents attributes or categories.

Constant

A characteristic that has only one value and does not change.

Nominal

Level of measurement where values name observations; qualitative; discrete; arithmetic beyond counting/proportions is meaningless.

Ordinal

Level of measurement with values that order observations; qualitative; discrete; allows ranking but not magnitude of differences.

Interval

Numerical level with equal intervals; quantitative; discrete or continuous; arbitrary zero; differences are meaningful but ratios are not.

Ratio

Numerical level with equal intervals and a true zero; allows ratio statements; quantitative; discrete or continuous.

Higher-to-Lower Level Conversion

Higher levels of measurement can be converted to lower levels, but converting downward loses information and you should avoid doing so if possible.

SPSS (IBM SPSS Statistics)

A statistical software package with a Data Editor window used for data analysis.

Population Parameter (Greek letters)

Parameters are population values, usually denoted by Greek letters (e.g., mu, sigma).

Sample Statistic (Latin/English letters)

Statistics are values from a sample, usually denoted by Latin/English letters (e.g., x̄, s).

Frequency Distribution

A fundamental way to organize and summarize data by listing frequencies for values or intervals.

Quantitative Data

Data that represent quantities or amounts (numbers).

Qualitative Data

Data that represent categories or attributes (labels).

Pie Chart

A circular chart showing the proportion of categories in qualitative data.

Bar Chart

A chart with rectangular bars representing category frequencies for qualitative data.

Histogram

A bar chart for quantitative data showing frequency by intervals.

Normal Distribution

A bell-shaped, symmetric distribution that approximates many real-world phenomena and underpins many inferential methods.

Negatively Skewed (Skewed to the Left)

A distribution with a longer tail toward lower values.

Positively Skewed (Skewed to the Right)

A distribution with a longer tail toward higher values.

Box Plot

A graphical display of distribution showing median, quartiles, and potential outliers for quantitative data.