Tag Archives: Two categorical variables

Chi-Square Goodness-of-Fit Test

Chi-Square Goodness-of-Fit (also referred to a Pearson’s Chi-Square Test) is a statistical method for determining how an actual or observed distribution of  categorical variables relates to a theoretical distribution of those same variables. The Chi-Square Test is a non-parametric test meaning that its graph is not expected to approximate a normal distribution curve.  An example […]

Confidence Interval for Two Independent Proportions

A confidence interval for two independent proportions is a tool used in inferential statistics to estimate a proportional* difference between two independent populations. These two populations must be distinguished by a single binary categorical variable; e.g. sex (male or female), but not blood type (A, B, AB, or O). With this information, it can be […]

Confidence Interval for Two Independent Proportions

Confidence interval for two independent proportions gives an estimated range of values, which is likely to include the difference between the two true population proportions for two categorical variables. For example, medical researchers may want to compare the proportions of men and women who suffered from heart attacks. The procedure for obtaining such an interval […]

Clustered Bar Graphs

A clustered bar graph is a type of bar graph in which you can  display multiple qualitative data variables. Unlike a bar graph where only one bin is used per marking on the x-axis, with a clustered bar graph multiple bins are grouped together.  You can see from the chart on the right that these bins are […]

Clustered Bar Graphs

A clustered bar graph, also called a grouped bar graph, is visually very similar to a “regular” bar graph, with one important difference in the data being presented: a second categorical variable is used to further break down the existing categories, thus aiding in the representation of data. A simple example of a clustered bar […]

Contingency Tables

A contingency table shows the frequencies of two categorical variables as they interact with each other. It is also known as a two-way table, cross tabulation, or cross tab. The frequencies are represented numerically. The totals of each column and each row  can be summed in the margins. Some uses for this table are: To examine the relationship […]

Contingency Tables

A contingency table is a statistical table that displays the frequencies of data elements according to defined categorical variables. The table consists of columns and rows which each represent a separate categorical variable and is used to display frequency relationships between two separate categorical variables. Often in the margins there are also totals of each row or column that […]