In most school achievement research, the relationships between achievement and explanatory variables follow the Newton and Einstein concept/principle and the viewpoint of the macro-observer: Deterministic measures based on the mean value of a sufficiently large number of schools. What if the relationships between achievement and explanatory…

Previous research has shown that young children make a perseverative, gravity-oriented, error when asked to predict the final location of a ball dropped down an S-shaped opaque tube (Hood, 1995). We asked if providing children with verbal information concerning the role that the tubes play, in determining the ball's trajectory would improve their…

IN THIS EXPERIMENT, 186 FRESHMAN ENGINEERING STUDENTS STUDIED ELEMENTARY PROBABILITY BY THESE INSTRUCTIONAL METHODS--(1) MULTIPLE CHOICE TEACHING MACHINES, (2) FREE-RESPONSE TEACHING MACHINES IN INDIVIDUAL BOOTHS AND IN CLASSROOMS, (3) PROGRAMED TEXTS REQUIRING OVERT RESPONSES AND GIVING CORRECT ANSWERS, (4) PROGRAMED TEXTS REQUIRING NO OVERT…

Experiments that assign intact groups to treatment conditions are increasingly common in social research. In educational research, the groups assigned are often schools. The design of group-randomized experiments requires knowledge of the intraclass correlation structure to compute statistical power and sample sizes required to achieve adequate…