Education statistics guide
How to Read Levene’s Test in SPSS Independent-Samples t Tests
Levene test checks whether group variances can be treated as equal and affects which SPSS t-test row to read.
Updated:
Problem
A common mistake is always reading the first SPSS row even when Levene test is significant.
Who should use this
Use this when writing research reports or assignments from SPSS independent-samples t-test output.
Formula and concept
Rule of thumb: Levene p >= .05 -> equal variances assumed; Levene p < .05 -> equal variances not assumed.
Levene test has the null hypothesis that variances are equal. If p >= .05, read Equal variances assumed. If p < .05, read Equal variances not assumed.
Levene test is not the mean-difference test. The group difference is interpreted from the matching t, df, p, and confidence interval row.
This page helps with calculation and reporting, but users should still confirm their research design, assumptions, and statistical interpretation.
Step by step
- Find Levene’s Test for Equality of Variances in the SPSS table.
- Read the Sig. value and compare it with .05.
- If p >= .05, use Equal variances assumed.
- If p < .05, use Equal variances not assumed and copy that row’s t, df, and p.
Worked example
Levene F = 6.21, p = .015. Because p < .05, use the Equal variances not assumed row. If that row has t = 2.48, df = 37.62, p = .018, those are the values to report.
Common mistakes
- Treating the Levene p value as the mean-difference p value.
- Using the first row after Levene is significant.
- Reporting only p without t, df, or effect size.
- Forgetting to confirm the design is really independent-samples.
Editorial and reproducibility review:
Turn the guide into an auditable decision
This section reworks the guide’s own example (Levene F=6.21, p=.015) and builds a second case with p above .05 to confirm the row choice is not a fixed habit.
Reproduce the example and confirm why p = .015 selects the second row
The worked example has Levene F=6.21, p=.015. Since .015 < .05, the correct row is Equal variances not assumed, which the example reports as t=2.48, df=37.62, p=.018 — those are the numbers that belong in the write-up, not the first row’s values. Deliberately practice the sequence "compare p to .05 first, then pick the row," rather than reading whichever row appears first in the SPSS output.
Build a case with p above .05 to confirm the row choice is not fixed
Set up your own case: Levene F=1.02, p=.318. Because .318 is not below .05, this time the correct row is Equal variances assumed — the first row, not the second. This checks that the decision genuinely depends on comparing p to .05 each time, rather than assuming every independent-samples t test reads the second row because the worked example happened to.
Confirm the two p values in the output answer different questions
The worked example’s Levene p is .015; the t-test p on the selected row is a separate number, .018. Self-check: .015 describes whether the two groups’ variances can be treated as equal, while .018 describes whether the group means differ — reporting .015 as if it were the significance of the mean difference is the exact mistake the guide calls out, and the two numbers coming from the same SPSS table does not make them interchangeable.
Completion criteria
- Reproduced the example (Levene p=.015) and confirmed it selects Equal variances not assumed (t=2.48, df=37.62, p=.018).
- Built a p ≥ .05 case (such as p=.318) and confirmed it selects the first row instead, showing the choice depends on the actual p value each time.
- Can state that the Levene p (.015) and the t-test p (.018) answer different questions and are not interchangeable.
- Confirmed the design is genuinely independent-samples before applying this rule at all.
Recommended tools
Related guides
FAQ
- What if Levene p equals .05?
- Many rules use p < .05 as significant. Follow your course or journal rule and state the criterion clearly.
- Does significant Levene mean group means differ?
- No. It concerns variances, not means.
- Can df be a decimal in the second row?
- Yes. Welch correction often produces decimal degrees of freedom.
- Do paired t tests use Levene?
- Usually no. Levene is mainly for independent group variance checks.
Next step
Use the SPSS interpreter to choose the correct row, then generate an APA 7 sentence.