Marcus Hammann

Students’ conceptions of the carbon cycle: identifying and interrelating components of the carbon cycle and tracing carbon atoms across the levels of biological organisation

Abstract This study investigates students’ conceptions of the carbon cycle with regard to the components they believe to be relevant to the carbon cycle, how they interrelate these components, the ways in which they trace carbon atoms, and the different levels of biological organisation they consider when doing so. A total of 142 students aged 13–16 years (grades 8–10) participated in the study. A total of 130 students completed the diagnostic task, and an additional 12 students completed both the diagnostic task and were interviewed. The primary results show that the students identified few components of the carbon cycle, tended to trace carbon atoms exclusively at the level of the organism, and had difficulties identifying organic carbon compounds, especially during processes in which carbon compounds are transformed. Considering the main educational implications, we recommend using an instructional strategy that traces carbon atoms across the different levels of biological organisation whilst connecting fragmented knowledge by integrating knowledge from physiology, biochemistry and ecology when teaching the carbon cycle.

Students' Reasons for Preferring Teleological Explanations.

ABSTRACT The teleological bias, a major learning obstacle, involves explaining biological phenomena in terms of purposes and goals. To probe the teleological bias, researchers have used acceptance judgement tasks and preference judgement tasks. In the present study, such tasks were used with German high school students (N = 353) for 10 phenomena from human biology, that were explained both teleologically and causally. A sub-sample (n = 26) was interviewed about the reasons for their preferences. The results showed that the students favoured teleological explanations over causal explanations. Although the students explained their preference judgements etiologically (i.e. teleologically and causally), they also referred to a wide range of non-etiological criteria (i.e. familiarity, complexity, relevance and five more criteria). When elaborating on their preference for causal explanations, the students often focused not on the causality of the phenomenon, but on mechanisms whose complexity they found attractive. When explaining their preference for teleological explanations, they often focused not teleologically on purposes and goals, but rather on functions, which they found familiar and relevant. Generally, students’ preference judgements rarely allowed for making inferences about causal reasoning and teleological reasoning, an issue that is controversial in the literature. Given that students were largely unaware of causality and teleology, their attention must be directed towards distinguishing between etiological and non-etiological reasoning. Implications for educational practice as well as for future research are discussed.

Offene Aufgaben codieren

Offene Aufgaben werden haufig in Tests eingesetzt, um Wissen und Verstandnis zu messen. Losungswege sind bei offenen Aufgaben nicht vorgegeben. Dies ermoglicht einerseits differenzierte Einblicke in das der Aufgabenlosung zugrundeliegende Verstandnis, erschwert allerdings aufgrund der Individualitat der Aufgabenbearbeitung die Codierung. Fur die Auswertung offener Aufgaben benotigt man Kategorien, die entweder deduktiv gewonnen werden oder aus den Antworten induktiv abgeleitet werden. Die Entwicklung eines Codierleitfadens ist wesentlich fur die Umwandlung von offenen Antworten in Daten, die statistisch analysiert werden konnen. Der Codierleitfaden ermoglicht die Zuordnung vielgestaltiger Antworten zu einer begrenzten Anzahl von Antwortkategorien. Er besteht aus den folgenden Elementen: Definition der Kategorien, Beschreibung von Codierregeln und Beispielen. Bei der Codierung von offenen Aufgaben sind die Gutekriterien qualitativer Forschung zu berucksichtigen. Dabei muss auch die Interrater-Reliabilitat sichergestellt werden, indem ermittelt wird, wie einig sich zwei unabhangige Codierer bei der Zuordnung von Antworten zu Kategorien sind. Weitere Gutekriterien sind Reliabilitat und Validitat. Letztere kann durch Triangulation von unabhangigen Indikatoren fur dasselbe Konstrukt untersucht werden.

The importance of research in educational change in Germany

When asked to explain the kind of work we do as researchers in biology education, I often use the term ‘research reforming practice’, which is indebted to Shawn M Glynn and Reinders Duit’s book called Learning Science in the Schools: Research Reforming Practice, an excellent collection of cutting-edge research that has reformed classroom practices. This book, like Wynne Harlen’s summary of research pertinent to effective science teaching, Effective Teaching of Science – A Research Review, reminds us that science education, ideally, connects research, theory and classroom practice and that innovations are evidence-based. In the last 15 years, educational research has informed quite dramatic changes in Germany and I would like to comment on the extent to which these changes are evidence-based.