Plant performance for a pulp mill is based on pulp brightness as measured by a reflectance meter. Each of the four shift operators (A, B, C, and D) made five pulp handsheets from unbleached pulp. Reflectance was measured for each of the handsheets using a brightness tester and these data are reported below. A goal of the experiment is to determine whether there are differences between the operators in making the handsheets and reading their brightness.