Log Transformation: Non-Normal Data, To Transform Or Not To Transform

The log transformation is often needed to transform data that has a natural boundary (e.g., zero) when assessing the stability of a process output response from a high level point of view.  The PDF article below shows mathematically why this is important.

Log Transformation: Non-Normal Data, To Transform Or Not To Transform

Transformations of data need to make physical sense.  The log normal transformation makes sense of situations when there a natural boundary.  If this is not done, control charts can indicate out of control conditions that are not correct.

log transformation can be very important when access process stability

This published Internet article was written as an alternative approach to analyzing non-normal data to that which was presented by Dr. Don Wheeler in a previous Quality Digest newsletter. This article illustrates, from a high level, or 30,000-foot-level, when and how to apply transformations and present results to others so that the data analysis leads to the most appropriate action or nonaction. Statistical software makes the application of transformations simple.

Contact Us to set up a time to discuss with Forrest Breyfogle how your organization might gain much from an Integrated Enterprise Excellence (IEE) Business Management System implementation that considers data transformations when appropriate.