Resumen de Fractional Factorial Experimental Design as a Teaching Tool for Quantitative Analysis
Fractional factorial experimental design is introduced as a group laboratory exercise in quantitative analysis. The classical gravimetric determination of chloride by precipitation with silver ion serves as the basis for this work. Using the designs of Genichi Taguchi, five experimental factors are studied in a two level, eight trial matrix. Students are assigned individual experiments called cells with assigned levels for the factors. Determinations of chloride in certified samples with varying levels of chloride (48% - 60%) are performed in triplicate by the students. The data is analyzed by calculating the level averages for each factor at each of their levels. Since many students run the experiments under less than optimum conditions, the connection between less than ideal precipitate characteristics and systematic error are emphasized.
