“…Skinner and colleagues have conducted a series of studies that showed that they could enhance students' perceptions of mathematics assignments by adding and interspersing additional problems that are briefer and easier than target problems (Cates & Skinner, 2000;Cates, Skinner, Watkins, & Rhymer, in press;Logan & Skinner, 1998;Skinner, Fletcher, Wildmon, & Belfiore, 1996;Skinner et al, 1999;Skinner, Robinson, Johns, Logan, & Belfiore, 1996;Wildmon, Skinner, McCurdy, & Sims, 1999;Wildmon, Skinner & McDade, 1998). In these studies, students were exposed to control assignments that contained only target mathematics problems (e.g., 679 ϫ 87 ϭ ) and experimental assignments where briefer, easier problems (e.g., 6 ϫ 8 ϭ ) were added and interspersed following every third problem.…”