📸 Binomial Test menu path in SPSS
What Is the Binomial Test?
The binomial test determines whether the observed proportion of a binary variable significantly differs from a specified test proportion. Unlike chi-square goodness of fit (which handles multiple categories), the binomial test handles exactly two categories and is exact for small samples.
Example: Is a surgery's observed success rate (72%) consistent with the literature-reported benchmark of 70%?
Running the Binomial Test in SPSS
Step 1: Analyze → Nonparametric Tests → Legacy Dialogs → Binomial.
Step 2: Move the binary variable to Test Variable List.
Step 3: Set Test Proportion to your hypothesized value (e.g., .70) → OK.
📸 Binomial test output — observed proportion vs. expected
APA Reporting
A binomial test indicated that the observed success rate (72%, n=58/80) did not significantly differ from the benchmark proportion of 70%, p=.823.