What re-expression to use?

[AlexKom]

Hello!

I) I can't understand, how can I determine what re-expression to use in order to linearize the scatterplot by just looking at the scatterplot?

II) And here is the problem: what is the difference between:
1) Certain groups are systematically excluded from the data
2) Certain groups are categorically excluded from the data.

As I understand, when groups are categorically excluded from the data, they are excluded completly...

Thank you very much!

 

[JohnM]

Alex,

I answered the first question in your other post.

For the second question, I believe the difference between "categorically" and "systematically" is very subtle, but groups categorically excluded are not even considered as part of the original sampling frame, and that groups systematically excluded are part of the original sampling frame, but because of a flaw in the sampling method, they are excluded from actual samples.