How do researchers decide which levels of an independent variable ...

[karen]

How do researchers decide which levels of an independent variable to include in an experiment?
 
  a. They attempt to make the levels as different from each other as possible.
  b. They use their knowledge of prior research findings.
  c. They use logic, common sense, and predictions from theories.
  d. all of the above

Question 2

In attempting to maximize variance from the independent variable, experimenters will often
 
  a. make the manipulated levels of the independent variable as different as possible.
  b. make the manipulated levels of the independent variable as similar as possible.
  c. conduct their research in the real world in order to maximize external validity.
  d. use dependent variables that are based in naturalistic observation.

[cpetit11]

Answer to Question 1

d

Answer to Question 2

a

[karen]

Wow, this really help

[xoxo123]

Thanks for the timely response, appreciate it