Abstract
The purpose of the investigation was to compare the effects of advance organizers and clustering as mediators of learning in lessons presented at a planetarium. The comparisons of the treatments were made at ability track levels in order to compare interaction effects.
The need for the study stemmed from the concern of planetarium educators about acceptance of their media as teaching instruments and legitimate parts of the school curriculum. Planetarium education has been interested in the design of successful learning programs for unique teaching equipment. Several studies have concluded that personality of the planetarium teacher is the major factor in predicting success of a lesson in the planetarium (Fletcher, 1980).
This investigation examined effects of mediators on learning in the planetarium. A related question posed by this investigation asked if design of the instruction can aid lower ability track students in reaching performance levels comparable with students of higher academic ability.
The scheme of the study was a nonrandomized pretest/posttest design with senior high school students in an intact school system as subjects of the study.
Thirty-six class sections including 832 students participated in the investigation. Nine class sections were randomly assigned to each treatment; therefore, there were three class section from each of the three academic track levels assigned to each treatment. The control treatment groups were instructed without the benefit of the learning mediators, clustering, or advance organizers. The other treatments included groups instructed with benefit of clustering, advance organizers, and a combination of these mediators of learning. The planetarium teacher presented all of the treatments to all of the subjects.
The instrument used for the pretest and posttest was designed by the investigator for use in a 1978 preliminary study comparing these treatments in the planetarium. The internal consistency was established through the Kuder - Richardson 21 formula. The content validity was established by a faculty committee representing all departments at Hempfield Area Senior Hight School.
An analysis of variance was conducted with the means of the posttest scores to investigate treatment effects, effects of academic level, and interactions. The general linear model was performed to further study regression and interactions. Treatments and levels were compared by the Duncan method. Individual treatments and levels of academic track were compared by the Schefe method.
The treatment group receiving both clustering and advanced organizers int he instruction were performed significantly higher on the posttest than any other treatment group; however the clustering treatment and the advance organizer treatment each produced significantly higher performance than the control treatment.
The track levels as established by Iowa Basics Reading Tests indicated performance differences between lowest track and upper two tracks, but no significant difference between the top two tracks. The analysis indicated that treatments caused the lowest track students of this investigation to perform at levels not significantly different from performance of higher academic track student in the control group.
The investigation produced data that indicate that the multiple use of mediators of learning can significantly improve learning outcome of planetarium presentations.
Studies that have reported planetarium learning to be dependent on characteristics of the teacher should be questioned in light of the information gathered by this study. This investigation determined that one teacher utilizing different mediator of learning can bring about significantly different learning outcomes.
