Theorists and researchers have suggested that some degree of individual control is an important and necessary instructional component. Students may better learn how to learn through making instructional choices and may feel more intrinsic motivation for learning, which ultimately results in better performance. In this study, learner and program control of content review were provided in science computer-assisted instruction (CAI). The instruction was completed by 98 eighth-grade students. Results indicate that students under learner control scored higher on the posttest than those under program control. Reading ability accounted for the highest proportion of variance in posttest scores. No differences were noted in time to completion between treatment groups. The overall results suggest that students given limited control over instruction can adjust their study behaviors appropriately and achieve greater learning in the same amount of time than can students not given such control.

SUMMARYPollens were evaluated with a bioassay that measures the relative nutritional efficiency of diets of young honeybees (Apis mellifera L.) rearing brood from eggs to the sealed cell stage of larval development. Relative nutritional efficiency was determined by calculation of the number of sealed cells produced per gram of diet consumed per bee per day. Saguaro (Cereus giganteus) pollen was used as the standard against which other pollens were tested. The bioassay results of pollens collected in 1977 showed that a diet of saguaro was more efficient than diets of cottonwood (Populus deltoides), but not of almond (Prunus dulcis). Bioassays of the pollens collected in 1978 showed that saguaro was more efficient than london rocket mustard (Sisymbrium irio) but not bladderpod mustard (Lesquerella gordoni). No brood was raised on a diet of dandelion pollen (Taraxacum officinale) or of dandelion fortified with L-arginine.

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This study investigated the effects of learner and program control over content review within science computer-assisted instruction (CAI). Ninth grade subjects completed learner and program controlled CAI and a unit posttest. Continuing motivation for learner and program control was measured by giving half the subjects a choice of control type for a subsequent session. Results indicated that program control resulted in better posttest performance for males. For females, learner control provided a nonsignificant advantage. This sex difference is discussed relative to a possible differential effort on the part of males and females. Results also reveal significant differences in continuing motivation for learner control, with subjects returning more frequently to learner control than program control in the second session. Strong student preferences for instruction via computers were also noted.

An olfactory bioassay procedure is described, and results from testing 28 alfalfa (Medicago sativa L.) clones for honey bee (Apis mellijera L.) olfactory compatibility are reported. Honey bee selection appeared to be based on quantity and quality of flower volatiles. When the honey bees were conditioned to one clone ("normal" alfalfa flower volatiles), bee selection indicated that alfalfa clones could be classified into three categories: compatible, neutral, and incompatible. The difference between compatible and neutral seemed to be based on lower quantities of volatiles produced by the neutral group; however, the one incompatible clone was discriminated against on the basis of olfactory quality. This bioassay procedure could be used as a tool for alfalfa breeders to select parent clones that are olfactorily compatible.