Stability Study - Box-Cox
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Stat > Regression > Stability Study > Stability Study > Box-Cox

Use to perform a Box-Cox transformation on your response data when the residuals are not normally distributed or do not have constant variance. Minitab transforms the response data and uses it in the analysis. Under most conditions, it is not necessary to correct for nonnormality unless the data are highly skewed. When you use Box-Cox, all response data must be greater than 0. Check your model carefully before using the Box-Cox transformation.

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Box-Cox Transformation

No transformation: Choose to use your original response data.

Optimal l (lambda): (This option is not available if batch is a random factor.) Choose to have Minitab search for an optimal value.

l  = 0 (natural log): Choose to use the natural log of the data.

l  = 0.5 (square root): Choose to use the square root of the data.

l : Choose to transform the data using another l value. Enter a value between -5 and 5.