Pre-experimental designs produce the greatest threat to internal ...

[geodog55]

Pre-experimental designs produce the greatest threat to internal and external validity because it provides
 
  a. either no control group or no way to equate the groups used
  b. a control group through randomization
  c. an equivalent-groups design
  d. none of the above

Question 2

It is generally inappropriate to generalize the results of a study to a population when the subjects are NOT
   randomly selected from the population because
 
  a. the number of subjects in the study is too small
  b. there is likely experimenter bias
  c. there is little assurance that the subjects are an adequate representation of the population
  d. there is little assurance that the data collected from the subjects is reliable

[kilada]

Answer to Question 1

A

Answer to Question 2

C