If we want to conclude that a given variable has a causal ...

[bobbie]

If we want to conclude that a given variable has a causal relation with a second variable, we have to be able to rule out other possible causal variables. The principle of causation involved here is the
 
  a. covariance rule.
  b. internal validity rule.
  c. causal ambiguity rule.
  d. temporal precedence rule.

Question 2

In a within-subjects design
 
  a. each participant serves in all experimental conditions
  b. participants are randomly assigned to conditions
  c. the dependent variable is measured only once
  d. changes within individual participants are studied
  e. participants are matched according to a personal characteristic

[Zack0mack0101@yahoo.com]

Answer to Question 1

B

Answer to Question 2

A

[bobbie]

TYSM

[covalentbond]

Gracias!