What does MS stand for?
| Full form | Mean Square |
|---|---|
| Category | Science & engineering |
| Type | Initialism |
The initialism MS stands for Mean Square in ANOVA tables. A row’s mean square is its sum of squares divided by the associated degrees of freedom: MS = SS / df.
Use the SS and df from the same table row. A mean square is different from the arithmetic mean of the original observations, and it is not a root-mean-square value. NIST distinguishes treatment and error mean squares; the name does not make every row’s denominator identical. A single MS value supplies neither an F-test result nor a p-value without the actual statistical model and evidence.
Meaning in context
- Mean
- The division by the associated degrees of freedom in this ANOVA quantity.
- Square
- The sum-of-squares context; this is different from averaging the raw observations.
Practical examples
Keep the denominator with its row
- Before
For SS = 42 and df = 6, MS must be 252.
- After
MS = 42 / 6 = 7.
Divide the corresponding sum of squares by degrees of freedom; do not multiply.
Avoid an inference leap
- Before
MS = 7 by itself proves the treatment effect is significant.
- After
The arithmetic yields the row’s mean square; a statistical conclusion needs the appropriate model and test.
A computed table cell is not a complete hypothesis test.
Original illustrative examples, not quotations or reports of actual events.
Use MS with clarity
Which two values do I divide to read a mean-square entry correctly?
See all guidance
Read the column
Use its named quantity.
MS means Mean Square in this ANOVA table.
Calculate a fictional row
Divide matching SS by df.
SS 42 and df 6 give MS 7.
Discuss a test
Keep the model and test separate.
An MS value alone provides no p-value.
Pair a row’s sum of squares with that row’s degrees of freedom before calculating MS.
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By AcronymIndex Editorial Team · Editorial policy