Transformations: Logged variables

On watching this video, students should be able to:

1. Explain what a non-linear transformation is and identify the log transformation as a type of non-linear transformation. 
2. Explain what can be achieved with a log transformation and identify situations when it may be useful.
3. Interpret each unit difference on the log scale as a multiplicative difference on the anti-logged (back transformed) scale
4. Interpret the mean and mean difference calculated from log transformed data after they have been back transformed to the original scale