For what groups does the Beck Depression Inventory show construct ...

[LCritchfi]

For what groups does the Beck Depression Inventory show construct validity? For what groups doesn't it?
 
  What will be an ideal response?

Question 2

Explain why case studies are useful for studying people with characteristics that are manifested idiosyncratically and that others don't share.
 
  What will be an ideal response?

[Ksanderson1296]

Answer to Question 1

The BDI shows good construct validity when researchers want to distinguish between mood disorders and other disorders. It also seems useful cross-culturally, showing good results with German and Portuguese speakers. It is also useful, in general, for the elderly.
The BDI is not so useful in assessing depression in people with Alzheimer's or those who are severely depressed.

Answer to Question 2

When researchers study rare traits and behaviors, it may not be possible to get a large group to study. In addition, if the effect of the trait differs across individuals who possess it, the differences across people may obscure interesting phenomena in single people.

[LCritchfi]

Thanks for the timely response, appreciate it

[scikid]

Excellent