A between-groups IV or quasi-IV means

A between-groups IV or quasi-IV means
 
  a. participants have been randomly assigned to conditions.
  b. each level contains different people.
  c. Both a and b may be true.
  d. Neither a nor b can be true.

Question 2

The fact that the distribution of random sample means is assumed to
  approximate normality is expressed in
 
  a. the Gaussian Law
  b. Pascal's triangle
  c. the Central Limit theorem
  d. none of these, since the premise is false

Question 3

When a post-facto relationship is found between two variables A and B, it
  is always possible, though not certain, that
 
  a. A caused B
  b. B caused A
  c. a third variable, X, has caused A plus B
  d. all of these

Question 4

When summarizing data from experiments, it is important that our _____ be a(n) _____ level of measurement.
 
  a. IV; nominal or ordinal
  b. IV; interval or ratio
  c. DV; nominal or ordinal
  d. DV; interval or ratio