An industrial psychologist is investigating the effects of work environment on employee attitudes. A group of 36 recently hired sales trainees were randomly assigned to one of 9 different "home rooms" - four trainees per room. Each room is identical except for wall color, with 9 different colors used. The psychologist wants to know whether room color has an effect on attitude, and, if so, wants to compare the mean attitudes of the trainees assigned to the 9 room colors. At the end of the training program, the attitude of each trainee was measured on a 100-pt. scale (the lower the score, the poorer the attitude). How many treatments are in this experiment?