A researcher investgating depression devises a study that contains the independent variable "Treatment," manipulated between-participants. Participants may experience "psychodynamic therapy," "cognitive behavioral therapy," "medication," or "waiting list placement." How many levels does the variable contain?
a) There are four levels to the variable.
b) There are three levels and a control condition.
c) There are four levels and "Treatment," making five.
The correct answer is c) There are four levels and "Treatment," making five.
To determine the number of levels in the independent variable "Treatment," we need to identify the distinct values or conditions that participants can be assigned to. In this case, participants can be assigned to one of four different treatments: psychodynamic therapy, cognitive behavioral therapy, medication, or waiting list placement. These four conditions represent the levels of the independent variable "Treatment."
However, it is important to note that the question also mentions the term "manipulated between-participants." This means that each participant is assigned to only one level of the independent variable, and there is no control condition explicitly mentioned. Hence, the variable contains four levels representing the treatments, and the term "Treatment" itself does not count as a level. Therefore, the correct answer is c) There are four levels and "Treatment," making five.