The usefulness of item sampling with unobtrusive measures and observational data is demonstrated. Particular emphasis is given to the question: Is item sampling appropriate for estimating the differences between means as well as the means themselves? A descriptive analysis is made of one aspect of a junior high school curriculum. Twenty four students were administered nine items from the "Resourcefulness Test" on three occasions. Item samples were then generated a posteriori from each 24 x 9 matrix, using balanced incomplete block design. Difference scores were examined. A description of student performance on each item across occasions constituted the curriculum evaluation, or monitoring part of the study. The results show that item sampling appears to be an effective technique for monitoring unobtrusive measures and observational data. (Author/BB)