Means (profile) plots
Plots the mean of a dependent variable for each level of a factor, one line per level of a second factor, with confidence-interval or standard-error bars. Crossing or diverging lines suggest an interaction.
Menu: Graphs → More charts → Means / profile plot…
When should I use it?
- Interpreting two-way ANOVA results.
What are the assumptions?
- A scale dependent variable and categorical factors.
How do I run it in StatLab?
- Choose the dependent variable, the horizontal-axis factor and (optionally) the separate-lines factor.
How do I read the output?
| Output | Meaning |
|---|---|
| Lines | Cell means; error bars as stated in the footnote. |
Worked example
On the practice survey dataset (File → Sample dataset), this command — which the dialog's Paste button also produces — runs the procedure:
PROC vizMeans /y=score /x=group /color='' /errorBars=ci.
Computed by StatLab's validated procedure code when this page was built. The example only illustrates the steps; choose variables that fit your own research question.
What are common mistakes?
- Calling non-parallel lines an interaction without the ANOVA test.