If human participants cannot be selected randomly, a. then ...

[james0929]

If human participants cannot be selected randomly,
 
  a. then select with a conscious bias and keep that in mind when interpreting data.
  b. then use non-human participants so you can get them at your convenience.
  c. it is imperative to match participants to each other (individual matching).
   d. it becomes more important to report exactly how participants were selected and
  assigned.

Question 2

When selecting participants from a population, experimenters need
 
  a. to be concerned about differences between volunteers and nonvolunteers.
  b. not worry about random selection with children
  c. not worry about representativeness if a large sample size is used.
  d. all of the above.

[mistyjohnson]

Answer to Question 1

D

Answer to Question 2

A

[james0929]

TYSM

[juliaf]

Thanks for the timely response, appreciate it