Suppose you are conducting an experiment that involves assigning each of 100 participants to one of two groups: Group A or Group B.Which of the following would not be considered to be a random assignment of participants to groups?
A)For each participant, flip a coin.If the coin lands heads up, assign him/her to Group A.If the coin lands tails up, assign him/her to Group B.
B)Put all 100 names in a hat and mix them up thoroughly.Draw 50 names from the hat and assign them to Group A.Everyone else is assigned to Group B.
C)As the participants show up for the study, assign the first 50 of them to Group A, and the last 50 to Group B.
D)All of the above methods are considered to be random assignments of participants to groups.

Question

Quizplus · Accepted Answer

Assigning participants based on the order in which they show up is not a random assignment method. It could introduce bias if the order in which participants arrive is related to variables being studied. A random assignment method should have an equal probability of assigning any participant to either group, without any systematic patterns or bias. A and B are both examples of random assignment methods.

Suppose You Are Conducting an Experiment That Involves Assigning Each