Introducing Freshman Engineering students to experimental design: Coffee brewing

At Rowan University, we have introduced experimental design throughout the Chemical Engineering Curriculum, in all levels of Engineering Clinics (freshman through senior) as well as the senior Unit Operations Laboratory. This paper describes a module used in our Freshman Clinic which introduces students to experimental design through a hands-on coffee brewing experiment and Statgraphics computer laboratory. Students perform a 2x2 experimental design to prepare coffee using a French press coffee maker, and the effects of water temperature and brewing time on the concentration of the coffee are determined. Hand calculations are performed to identify the effect of each variable and develop a predictive model for coffee concentration. In a follow-up computer laboratory, Statgraphics computer software is used to perform the same analysis and the results are compared with the hand calculations. Assessment results indicate that 85% of students successfully achieved learning objectives related experimental design.