Describe and differentiate the three methods to control ...

[j.rubin]

Describe and differentiate the three methods to control extraneous variables.
 
  What will be an ideal response?

Question 2

Random error can drastically affect the average performance for a group.
 
  a. True
  b. False
  Indicate whether the statement is true or false

[frre432]

Answer to Question 1

Extraneous variables can be controlled by holding them constant, or by matching them across treatment conditions, or by randomizing them across treatment conditions. If a variable is held constant, then it is the same for all treatment conditions and cannot be responsible for differences between treatments. Similarly, if a variable is matched across treatments, then it is the same for all treatment conditions and cannot be responsible for differences between treatments. Finally, if a variable is randomized across treatments, then it should not change systematically from one treatment to another, and it should not be responsible for differences between treatments.

Answer to Question 2

False

[j.rubin]

Thanks for the timely response, appreciate it

[Dnite]

Gracias!