Correlation Coefficient, ContingencyT, Nominal, Charts

What is correlation Coefficient

Number describing the strength and direction of relationship between two variables (interval/ratio)

Ranges from -1 to +1

Univariate statistics

statistical measures/procedures that include only one variable

Bivariate statistics

statistical measures/procedures that include two variables

Multivariate statistics

statistical measures/procedures that include more than two variables

Positive Correlation coefficient

Variables increase together.

As one goes up the other goes down

Negative correlation coefficient

As one increases, the other decreases

What does the strength of a correlation mean

How tightly the variables move together

Correlation is ____ statistic

Bivariate

Correlation uses which tool

Scatterplot

What is a contingency table (cross tabulation)

A table showing how two categorical variables are related by showing the frequency counts for each combination

When do you use a cross tab

When both variables are nominal or ordinal

Why use percentages in cross tab

To compare groups fairly when sizes differ

What does nominal mean

Category names with no order and no math

Ex gender province diagnosis

What does ordinal mean

Categorie with order but unequal spacing

Ex race results, likert scales, rankings

What does interval mean

Equal intervals but zero doesnt mean none

Ex. C, F, test scores

What does Ratio mean

Equal intervals with a true zero all math works

Ex. height, weight, time, hours studied

What is a bar graph

Graph with separate vertical bars showing frequencies

Used when variable is categorical (nominal or ordinal)

What is a histogram

A graph showing frequency distribution of quantitative variable

Used when variable is quantitative (Interval/ratio)

Histograms show___ that a bar graph doesnt

Shape

What is a scatterplot

Graph showing relationship between two quantitative variables

X axis: IV

Y axis: DV

Each dot = individual pair of scores