|Franke, G: Untersuchungen zum Wissenserwerb, zur kognitiven Belastung und zu emotionalen Faktoren im experimentellen Unterricht über Grundlagen der Gentechnik im Lernort Labor unter besonderer Berücksichtigung von Schülervorstellungen, (2011)|
Gene technology is part of the official 10th grade syllabus of the 6-stage “Realschule” in Bavaria (i.e. medium achieving high school students). Within the Gene-technology Demonstration Laboratory of the University of Bayreuth 293 male and female students from 13 North-Bavarian classes attended the intervention programme. The educational module included an understanding of the basics of gene technology in a practical lesson unit; the involved experiments dealt with restriction and ligation of DNA, transformation of E. coli-bacteria, as well as an inoculation of the bacterial samples on agar plates. Three empirical studies supported the evaluation of the teaching success of these experimental lessons: The study examined the effects on different cognitive factors, such as knowledge acquisition or mental effort, but also on affective factors, such as state-emotions (e.g., interest and well-being), as well as possible conceptual change. A main focus was laid on effects when students‟ alternative conceptions were considered as bases to build upon the lesson unit. For this purpose, the students were split into two intervention groups (I-1, I-2). Both groups received the same experimental lessons in the Demonstration Laboratory with one difference: students in I-2 were additionally confronted with alternative conceptions of gene technology. These conceptions about eight concepts and processes of gene technology of 144 students had initially been collected and categorized in another study. The inclusion of these conceptions was realised on the basis of a constructivist teaching model. The results of all three empirical studies proved that dealing with students‟ alternative conceptions in those lessons affected the learners positively in various ways: male and female students of I-2 (“alternative conceptions”) were more interested and showed a higher well-being than those in I-1. They also achieved significantly better results in the knowledge-tests conducted after the lessons, while they showed a lowered mental effort. In the short-term, the students of this group replaced alternative conceptions with the specialised scientific conceptions. The special effect of the confrontation method on the male students has to be emphasised: In contrast to female students, they felt increasingly encouraged by a consideration of their conceptions in the lessons. Taking all these positive results together, an expansion of the quantitative capture of students‟ alternative conceptions about other subjects is advisable in order to support the teaching situations.