In an experiment examining the effects of stress on decision making, researchers use two independent variables with two levels each. The first independent variable is temperature of the room (65 degrees and 95 degrees) and the second is noise in the room (present or absent). Researchers randomly assign participants to one of the two temperature conditions and then have the participants perform decision-making tasks in both conditions of the noise variable (present and absent). The researchers allow subjects to rest in between exposure to the noise variable and use counterbalancing of the noise conditions. This experiment uses a(n) design, since subjects are randomly assigned to one independent variable, but exposed to all conditions of the second independent variable.