Statistical Evaluation of Data

Descriptive Statistics

Methods that help researchers organize, summarize, and simplify results from a research study

Inferential Statistics

Methods that use results obtained from samples to help make generalizations about populations

Population

the entire set of individuals of interest to a researcher; know as the target popluation or the group in which study results can be extrapolated to

Sample

A group of individuals selected from a population intended to represent the population in a research study

Parameter

Refers to a summary value that describes a population

Statistic

Refers to a summary value that describes a sample

Frequency Distributions

A method of simplifying and organizing a set of scores by grouping them into a organized display (table consisting of two columns of info)

Histogram

Displays a bar above each score so that the height of the bar indicates the frequency of occurrence for the given score (interval/ratio)

Polygon

Displays a point above each score so that the height of the point indicates the frequency of occurrence for the given score (interval/ratio)

Bar Graph

Displays a bar above each score so that the height of the bar indicates the frequency of occurrence for the group category (nominal/ordinal)

Central Tendency

A statistical measure that identifies a single score to define as the centre of a distribution; the value that is most typical or presentative of the group

Mean

The mathematical average of the scores

Median

The score that divides a distribution in half

Mode

The most commonly occurring score