How to do a Chi square or Fisher's exact test in GraphPad Prism
You do not have to calculate the counts yourself before entering Prism.
| Test Type | Purpose | Example | | :--- | :--- | :--- | | | Compare observed frequencies to expected theoretical proportions. | "Does our sample of 100 M&M’s match the manufacturer’s claimed color distribution (30% brown, 20% blue...)?" | | Chi-square Contingency (Independence) | Determine if two categorical variables are associated (dependent). | "Is there a relationship between smoking status (Smoker/Non-smoker) and lung disease (Yes/No)?" | chi square graphpad
For $2 \times 2$ tables, some statisticians prefer Yates' continuity correction. Prism offers this as an option in the parameters window (" Yates' correction (recommended)"). In modern statistics, Fisher’s Exact Test is generally preferred over Yates' correction for small samples, so sticking with the default or Fisher's is usually best.
: It automatically generates bar charts from your contingency tables, which can be further customized and linked directly to your statistical findings. How to do a Chi square or Fisher's
: In the "New Data Table and Graph" dialog, select Contingency . Note that Prism requires you to enter summarized counts (observed numbers) directly; it cannot cross-tabulate raw data automatically.
If you have a column of "Group" and another column of "Outcome": | "Is there a relationship between smoking status
: Click the Analyze button and choose Chi-square (and Fisher's exact) test from the list of contingency table analyses. Select Options : Choose Chi-square test as the method to compute the
: Prism automatically generates a bar chart (interleaved or stacked) to help you visualize the proportions in each category.