Suppose you wanted to compare students in two different classes, ...

[jlmhmf]

Suppose you wanted to compare students in two different classes, assessing whether research methods or social psychology leads to more favorable ratings of how interesting psychology is.
 
  Why would it be important to consider selection, attrition, and history?
  What will be an ideal response?

Question 2

What is the difference between symmetric and asymmetric transfer?
 
  What will be an ideal response?

[mbcrismon]

Answer to Question 1

(a) Selectiondifferent types of students may take the two different classes, so they may differ in their ratings of psychology at the start.
(b) Attritiondifferent types of students may drop the two courses, especially if one course is required and they have to stick with it.
(c) Historysomething in one class, like an instructor's change in grading policies may affect students positively or negatively.

Answer to Question 2

Symmetric transfer takes place when condition B, following condition A is affected the same way as A is after following B. In asymmetric transfer, the effect of B on A is different than the effect of A on B.

[jlmhmf]

Thanks for the timely response, appreciate it

[xiaomengxian]

TYSM