KEVOS® MAKEOS · Quality

One-Way ANOVA Check (Group Means, F Test, Machines, Suppliers or Settings)

I have measurements from two to four machines, suppliers, shifts or settings: do their means really differ, or is the difference within the scatter inside each group?

One-way analysis of variance for up to four groups of up to six measurements each: the group means, the sums of squares between and within groups, the mean squares, the F statistic, the critical F value and p-value for your significance level, and whether the group means differ.

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How this tool works

Inputs, units and where to find them

InputUnitTypical source
Number of groupsgroupsHow many of the groups below to compare (2 to 4).
Significance level%Chance of finding a difference when there is none (5 % is common).
Group 1
Group 1 values usedvaluesHow many of group 1’s values to use, from the first.
Group 1 value 1Measurement 1 from group 1 (one machine, supplier, shift or setting).
Group 1 value 2Measurement 2 from group 1 (one machine, supplier, shift or setting).
Group 1 value 3Measurement 3 from group 1 (one machine, supplier, shift or setting).
Group 1 value 4Measurement 4 from group 1 (one machine, supplier, shift or setting).
Group 1 value 5Measurement 5 from group 1 (one machine, supplier, shift or setting).
Group 1 value 6Measurement 6 from group 1 (one machine, supplier, shift or setting).
Group 2
Group 2 values usedvaluesHow many of group 2’s values to use, from the first.
Group 2 value 1Measurement 1 from group 2 (one machine, supplier, shift or setting).
Group 2 value 2Measurement 2 from group 2 (one machine, supplier, shift or setting).
Group 2 value 3Measurement 3 from group 2 (one machine, supplier, shift or setting).
Group 2 value 4Measurement 4 from group 2 (one machine, supplier, shift or setting).
Group 2 value 5Measurement 5 from group 2 (one machine, supplier, shift or setting).
Group 2 value 6Measurement 6 from group 2 (one machine, supplier, shift or setting).
Group 3
Group 3 values usedvaluesHow many of group 3’s values to use, from the first.
Group 3 value 1Measurement 1 from group 3 (one machine, supplier, shift or setting).
Group 3 value 2Measurement 2 from group 3 (one machine, supplier, shift or setting).
Group 3 value 3Measurement 3 from group 3 (one machine, supplier, shift or setting).
Group 3 value 4Measurement 4 from group 3 (one machine, supplier, shift or setting).
Group 3 value 5Measurement 5 from group 3 (one machine, supplier, shift or setting).
Group 3 value 6Measurement 6 from group 3 (one machine, supplier, shift or setting).
Group 4
Group 4 values usedvaluesHow many of group 4’s values to use, from the first.
Group 4 value 1Measurement 1 from group 4 (one machine, supplier, shift or setting).
Group 4 value 2Measurement 2 from group 4 (one machine, supplier, shift or setting).
Group 4 value 3Measurement 3 from group 4 (one machine, supplier, shift or setting).
Group 4 value 4Measurement 4 from group 4 (one machine, supplier, shift or setting).
Group 4 value 5Measurement 5 from group 4 (one machine, supplier, shift or setting).
Group 4 value 6Measurement 6 from group 4 (one machine, supplier, shift or setting).

What each input means

Open an input to see what it is, its units, the worked example and the common mistakes, with a small diagram.

What this means: Number of groups
Illustration: Number of groupsA row of identical items being counted; Number of groups is how many there are.kExample: 3 groupsNumber of groups
What it is
How many groups are compared, from two to four; each group is one machine, supplier, shift, operator or setting.
Units and format
Enter a number in groups: groups. The form accepts 2 groups to 4 groups. Use a whole number. Required: the tool does not calculate until every input is valid.
Example
The form opens with 3 groups as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
More groups add degrees of freedom between groups and change the critical F value.
Get it right
Compare only groups that differ in the one factor you are studying, made otherwise the same way.
What this means: Significance level
Illustration: Significance levelA bar of 100 parts with the share marked; Significance level is that share out of 100. The bar follows the value you type.0 %100 %αExample: 5%Significance level
What it is
The significance level: the chance you accept of declaring that the group means differ when there is no real difference.
Units and format
Enter a number in %: percent: the number is read as a percentage, so type 8 for 8 %. The form accepts 0.1% to 20%. Required: the tool does not calculate until every input is valid.
Example
The form opens with 5% as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
A smaller level widens the acceptance region, so a difference must be larger to show.
Get it right
Use 5 % unless your procedure says otherwise; 1 % for decisions where a false alarm is costly.

Group 1

What this means: Group 1 values used
Illustration: Group 1 values usedA row of identical items being counted; Group 1 values used is how many there are.n1Example: 5 valuesGroup 1 values used
What it is
How many of the six value boxes for group 1 are used, counting from the first; the rest are ignored.
Units and format
Enter a number in values: values. The form accepts 1 values to 6 values. Use a whole number. Required: the tool does not calculate until every input is valid.
Example
The form opens with 5 values as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
More values per group make the error mean square more reliable and smaller differences detectable.
Get it right
Enter group 1’s values from the first box onwards with no gaps; groups may have different counts.
What this means: Group 1 value 1
Illustration: Group 1 value 1A number line with a marker at the value of Group 1 value 1, between its lowest and highest accepted values.−10⁹10⁹y11Example: 6.9Group 1 value 1
What it is
Measurement 1 from group 1, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 6.9 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 1’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 1 the same way as the other groups, and in random order if you can.
What this means: Group 1 value 2
Illustration: Group 1 value 2A number line with a marker at the value of Group 1 value 2, between its lowest and highest accepted values.−10⁹10⁹y12Example: 5.4Group 1 value 2
What it is
Measurement 2 from group 1, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 5.4 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 1’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 1 the same way as the other groups, and in random order if you can.
What this means: Group 1 value 3
Illustration: Group 1 value 3A number line with a marker at the value of Group 1 value 3, between its lowest and highest accepted values.−10⁹10⁹y13Example: 5.8Group 1 value 3
What it is
Measurement 3 from group 1, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 5.8 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 1’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 1 the same way as the other groups, and in random order if you can.
What this means: Group 1 value 4
Illustration: Group 1 value 4A number line with a marker at the value of Group 1 value 4, between its lowest and highest accepted values.−10⁹10⁹y14Example: 4.6Group 1 value 4
What it is
Measurement 4 from group 1, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 4.6 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 1’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 1 the same way as the other groups, and in random order if you can.
What this means: Group 1 value 5
Illustration: Group 1 value 5A number line with a marker at the value of Group 1 value 5, between its lowest and highest accepted values.−10⁹10⁹y15Example: 4Group 1 value 5
What it is
Measurement 5 from group 1, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 4 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 1’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 1 the same way as the other groups, and in random order if you can.
What this means: Group 1 value 6
Illustration: Group 1 value 6A number line with a marker at the value of Group 1 value 6, between its lowest and highest accepted values.−10⁹10⁹y16Example: 5.5Group 1 value 6
What it is
Measurement 6 from group 1, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 5.5 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 1’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 1 the same way as the other groups, and in random order if you can.

Group 2

What this means: Group 2 values used
Illustration: Group 2 values usedA row of identical items being counted; Group 2 values used is how many there are.n2Example: 5 valuesGroup 2 values used
What it is
How many of the six value boxes for group 2 are used, counting from the first; the rest are ignored.
Units and format
Enter a number in values: values. The form accepts 1 values to 6 values. Use a whole number. Required: the tool does not calculate until every input is valid.
Example
The form opens with 5 values as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
More values per group make the error mean square more reliable and smaller differences detectable.
Get it right
Enter group 2’s values from the first box onwards with no gaps; groups may have different counts.
What this means: Group 2 value 1
Illustration: Group 2 value 1A number line with a marker at the value of Group 2 value 1, between its lowest and highest accepted values.−10⁹10⁹y21Example: 8.3Group 2 value 1
What it is
Measurement 1 from group 2, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 8.3 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 2’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 2 the same way as the other groups, and in random order if you can.
What this means: Group 2 value 2
Illustration: Group 2 value 2A number line with a marker at the value of Group 2 value 2, between its lowest and highest accepted values.−10⁹10⁹y22Example: 6.8Group 2 value 2
What it is
Measurement 2 from group 2, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 6.8 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 2’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 2 the same way as the other groups, and in random order if you can.
What this means: Group 2 value 3
Illustration: Group 2 value 3A number line with a marker at the value of Group 2 value 3, between its lowest and highest accepted values.−10⁹10⁹y23Example: 7.8Group 2 value 3
What it is
Measurement 3 from group 2, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 7.8 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 2’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 2 the same way as the other groups, and in random order if you can.
What this means: Group 2 value 4
Illustration: Group 2 value 4A number line with a marker at the value of Group 2 value 4, between its lowest and highest accepted values.−10⁹10⁹y24Example: 9.2Group 2 value 4
What it is
Measurement 4 from group 2, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 9.2 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 2’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 2 the same way as the other groups, and in random order if you can.
What this means: Group 2 value 5
Illustration: Group 2 value 5A number line with a marker at the value of Group 2 value 5, between its lowest and highest accepted values.−10⁹10⁹y25Example: 6.5Group 2 value 5
What it is
Measurement 5 from group 2, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 6.5 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 2’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 2 the same way as the other groups, and in random order if you can.
What this means: Group 2 value 6
Illustration: Group 2 value 6A number line with a marker at the value of Group 2 value 6, between its lowest and highest accepted values.−10⁹10⁹y26Example: 7.5Group 2 value 6
What it is
Measurement 6 from group 2, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 7.5 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 2’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 2 the same way as the other groups, and in random order if you can.

Group 3

What this means: Group 3 values used
Illustration: Group 3 values usedA row of identical items being counted; Group 3 values used is how many there are.n3Example: 5 valuesGroup 3 values used
What it is
How many of the six value boxes for group 3 are used, counting from the first; the rest are ignored.
Units and format
Enter a number in values: values. The form accepts 1 values to 6 values. Use a whole number. Required: the tool does not calculate until every input is valid.
Example
The form opens with 5 values as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
More values per group make the error mean square more reliable and smaller differences detectable.
Get it right
Enter group 3’s values from the first box onwards with no gaps; groups may have different counts.
What this means: Group 3 value 1
Illustration: Group 3 value 1A number line with a marker at the value of Group 3 value 1, between its lowest and highest accepted values.−10⁹10⁹y31Example: 8Group 3 value 1
What it is
Measurement 1 from group 3, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 8 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 3’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 3 the same way as the other groups, and in random order if you can.
What this means: Group 3 value 2
Illustration: Group 3 value 2A number line with a marker at the value of Group 3 value 2, between its lowest and highest accepted values.−10⁹10⁹y32Example: 10.5Group 3 value 2
What it is
Measurement 2 from group 3, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 10.5 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 3’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 3 the same way as the other groups, and in random order if you can.
What this means: Group 3 value 3
Illustration: Group 3 value 3A number line with a marker at the value of Group 3 value 3, between its lowest and highest accepted values.−10⁹10⁹y33Example: 8.1Group 3 value 3
What it is
Measurement 3 from group 3, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 8.1 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 3’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 3 the same way as the other groups, and in random order if you can.
What this means: Group 3 value 4
Illustration: Group 3 value 4A number line with a marker at the value of Group 3 value 4, between its lowest and highest accepted values.−10⁹10⁹y34Example: 6.9Group 3 value 4
What it is
Measurement 4 from group 3, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 6.9 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 3’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 3 the same way as the other groups, and in random order if you can.
What this means: Group 3 value 5
Illustration: Group 3 value 5A number line with a marker at the value of Group 3 value 5, between its lowest and highest accepted values.−10⁹10⁹y35Example: 9.3Group 3 value 5
What it is
Measurement 5 from group 3, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 9.3 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 3’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 3 the same way as the other groups, and in random order if you can.
What this means: Group 3 value 6
Illustration: Group 3 value 6A number line with a marker at the value of Group 3 value 6, between its lowest and highest accepted values.−10⁹10⁹y36Example: 8.6Group 3 value 6
What it is
Measurement 6 from group 3, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 8.6 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 3’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 3 the same way as the other groups, and in random order if you can.

Group 4

What this means: Group 4 values used
Illustration: Group 4 values usedA row of identical items being counted; Group 4 values used is how many there are.n4Example: 5 valuesGroup 4 values used
What it is
How many of the six value boxes for group 4 are used, counting from the first; the rest are ignored.
Units and format
Enter a number in values: values. The form accepts 1 values to 6 values. Use a whole number. Required: the tool does not calculate until every input is valid.
Example
The form opens with 5 values as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
More values per group make the error mean square more reliable and smaller differences detectable.
Get it right
Enter group 4’s values from the first box onwards with no gaps; groups may have different counts.
What this means: Group 4 value 1
Illustration: Group 4 value 1A number line with a marker at the value of Group 4 value 1, between its lowest and highest accepted values.−10⁹10⁹y41Example: 7Group 4 value 1
What it is
Measurement 1 from group 4, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 7 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 4’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 4 the same way as the other groups, and in random order if you can.
What this means: Group 4 value 2
Illustration: Group 4 value 2A number line with a marker at the value of Group 4 value 2, between its lowest and highest accepted values.−10⁹10⁹y42Example: 7.5Group 4 value 2
What it is
Measurement 2 from group 4, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 7.5 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 4’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 4 the same way as the other groups, and in random order if you can.
What this means: Group 4 value 3
Illustration: Group 4 value 3A number line with a marker at the value of Group 4 value 3, between its lowest and highest accepted values.−10⁹10⁹y43Example: 6.8Group 4 value 3
What it is
Measurement 3 from group 4, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 6.8 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 4’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 4 the same way as the other groups, and in random order if you can.
What this means: Group 4 value 4
Illustration: Group 4 value 4A number line with a marker at the value of Group 4 value 4, between its lowest and highest accepted values.−10⁹10⁹y44Example: 7.2Group 4 value 4
What it is
Measurement 4 from group 4, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 7.2 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 4’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 4 the same way as the other groups, and in random order if you can.
What this means: Group 4 value 5
Illustration: Group 4 value 5A number line with a marker at the value of Group 4 value 5, between its lowest and highest accepted values.−10⁹10⁹y45Example: 7.1Group 4 value 5
What it is
Measurement 5 from group 4, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 7.1 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 4’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 4 the same way as the other groups, and in random order if you can.
What this means: Group 4 value 6
Illustration: Group 4 value 6A number line with a marker at the value of Group 4 value 6, between its lowest and highest accepted values.−10⁹10⁹y46Example: 6.9Group 4 value 6
What it is
Measurement 6 from group 4, where a group is one machine, supplier, shift, operator or setting being compared.
Units and format
Enter a plain number with no unit. Negative values are accepted. Required: the tool does not calculate until every input is valid.
Example
The form opens with 6.9 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Effect on the result
Moves group 4’s mean and adds to the scatter within groups, which sets the error mean square.
Get it right
Measure every part in group 4 the same way as the other groups, and in random order if you can.

Method and formulas

  1. Treatment sum of squares SST = Σ nᵢ (ȳᵢ − ȳ)²; error sum of squares SSE = Σ Σ (yᵢⱼ − ȳᵢ)²; total = SST + SSE (NIST e-Handbook 7.4.3.3–7.4.3.4).
  2. MST = SST ÷ (k − 1), MSE = SSE ÷ (N − k), F = MST ÷ MSE.
  3. The means differ when F exceeds the upper α point of the F distribution with k − 1 and N − k degrees of freedom.
  4. Example: F = 9.5911 against a critical value of 3.8853 (p = 0.0032482).

Limitations

  • Assumes each group is roughly normal with about the same spread and that measurements are independent; check the spreads (the F test for two variances or a plot) before relying on the result.
  • A significant F says at least one mean differs, not which: compare the group means, or follow up with a multiple-comparison method (NIST 7.4.7).
  • Example values are illustrations. Replace them with values for your actual task.

Typical uses

  • Compare parts made on several machines or cavities
  • Test whether a process setting changes the result
  • Compare material from different suppliers or lots

Who it is for

  • Quality and process engineers
  • Test and development engineers
  • Continuous improvement staff

What you get

  • Group means
  • Sums of squares and mean squares
  • F statistic, critical value and p-value
  • Whether the means differ

Interpreting the result

  • Practical importance is separate from significance: look at the size of the difference between means against your tolerance.

References

  • NIST/SEMATECH e-Handbook of Statistical Methods, 7.4.3.3 The ANOVA table and tests of hypotheses about means — https://www.itl.nist.gov/div898/handbook/prc/section4/prc433.htm
  • NIST/SEMATECH e-Handbook of Statistical Methods, 7.4.3.4 One-way ANOVA calculations — https://www.itl.nist.gov/div898/handbook/prc/section4/prc434.htm

Learn the Concepts Behind This Tool

These KEVOS® Library readings explain the method this tool uses, with worked examples.

KEVOS® tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.

Open the One-Way ANOVA Check (Group Means, F Test, Machines, Suppliers or Settings) calculator

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