The effects of a greenhouse laboratory experience on the knowledge and attitudes of secondary horticulture students

Purpose. The purpose of this study was to assess the effectiveness of instruction in horticulture programs that did or did not provide a greenhouse laboratory experience. Data from 168 students in 13 vocational horticulture programs were included in this study. To test the major hypothesis a posttest only, control group quasi-experimental design was selected. The stratified sample was identified using a random number selection procedure. The sample was drawn with replacements on a cluster basis.;Procedures. This study involved teaching a 15 lesson unit on poinsettia production to two groups of high school horticulture students. One group received instruction that included a greenhouse laboratory experience and the other group did not have a greenhouse laboratory experience. Data were collected using a knowledge posttest, an attitude toward subject matter test, and questionnaires to collect selected information about students and teachers.;An analysis of variance procedure was used to test for differences between the groups for knowledge and attitude toward subject matter scores. A Pearson correlation procedure was used to estimate the relationship of post-experiment knowledge scores with selected student and teacher characteristics.;Findings. (a) There was a significant difference between the post-experiment knowledge test mean scores for the two treatment groups, (b) There was not a significant difference between the post-experiment attitude mean scores for the two treatment groups, (c) No significant relationship was found among students' post-experiment knowledge test mean score and selected teacher characteristics. However, significant relationships were found between post-experiment knowledge scores and students' horticultural SAE and exposure to a greenhouse laboratory experience.;Conclusions. (a) There is an advantage in student knowledge acquisition for students receiving instruction with access to a greenhouse laboratory experience, (b) Students' attitudes toward poinsettia production are not affected by whether or not students have a greenhouse laboratory experience, (c) Students who have a horticultural SAE project tend to have higher knowledge test scores.