Dirk Krüger

Testing Models: A Key Aspect to Promote Teaching Activities Related to Models and Modelling in Biology Lessons?

This study investigated biology teachers’ (N = 148) understanding of models and modelling (MoMo), their model-related teaching activities and relations between the two. A framework which distinguishes five aspects of MoMo in science (nature of models, multiple models, purpose of models, testing models and changing models) served as a theoretical background. Teachers’ understanding of MoMo was assessed using constructed-response items which were analysed qualitatively based on a coding scheme. The biology teachers mainly expressed a limited understanding of models as copies or idealised depictions used to show or to explain something. Model-related teaching activities were assessed through rating-scale items. The findings propose that models are primarily generated in biology lessons to show or to explain something but are rarely contrasted with other models, evaluated and modified. Significant correlations between teachers’ understanding of the aspect testing models and their intensity of model-related teaching activities were found. This suggests that the aspect testing models is a key aspect of promoting teaching activities related to MoMo in biology lessons. The findings are discussed with respect to relevant literature about MoMo in science education and educational implications are provided.

Fostering pre-service teachers’ views about nature of science: evaluation of a new STEM curriculum

Background: An elaborated understanding of Nature of Science (NOS) is seen as an important part of scientific literacy. In order to enable teachers to adequately discuss NOS in their lessons, various approaches have recently been employed to improve teachers’ understanding of NOS. Purpose: This study investigated the effect of participating in a newly developed Science, Technology, Engineering and Mathematics (STEM) curriculum at the Freie Universität Berlin (Germany) on pre-service teachers’ NOS views. Program description: In the new STEM curriculum, two versions of explicitly teaching NOS, which are discussed in the literature, have been adopted: the pre-service teachers explicitly reflect upon nature and history of science (version one) as well as conduct own scientific investigations (version two). Sample: N = 76 pre-service teachers from different semester levels (cross-sectional study) who participated in the new STEM curriculum took part in this study (intervention group). As control groups, students who did not partake in the new curriculum participated (pre-service primary (N = 134), science (N = 198), and no-science (N = 161) teachers). Design and methods: In order to allow an economic assessment, a testing instrument with closed-item formats was developed to assess the respondents’ views about six NOS aspects. Results: The intervention group shows significantly more elaborated NOS views than a relevant control group (p < .01, g = .48). Additionally, a one-way ANOVA reveals a positive effect of semester level on NOS views for the intervention group (p < .01; η² = .16) but not for the control groups. Conclusion: The findings support evidence suggesting that explicit approaches are effective when fostering an informed understanding of NOS. More specifically, a sequence of both versions of explicitly teaching NOS discussed in the literature seems to be a way to successfully promote pre-service teachers’ NOS understanding.

Es gibt nichts Praktischeres als eine gute Theorie

In der Umgangssprache bedeutet theoretisch, dass etwas mit einer gewissen Unsicherheit behauptet wird. Man sagt, man hat nur eine Theorie, und meint, dass die eigene Argumentation ziemlich fragwürdig erscheint. In der Wissenschaft dagegen bildet die Theorie das Fundament einer Forschungsarbeit: Hat ein Forscher Untersuchungsfaktoren identifiziert, so muss er ihre Beziehungen beschreiben, ihre Abhängigkeiten oder gegenseitigen Beeinflussungen kennen und gegebenenfalls weitere relevante Faktoren in die Untersuchung mit einbeziehen. Aussagen über ein solches Beziehungsnetz verschiedener Faktoren liefert die Theorie. Eine Theorie stellt also ein Hypothesensystem dar, das durch wiederholte und aus diversen Richtungen abgesicherte Ergebnisse der Grundlagenforschung bestätigt und damit als vertrauensvoll gelten kann. Eine Theorie ist ein abstraktes Gedankenkonstrukt. Eine Theorie entsteht durch reines Denken und bedarf keiner Realisierung. Sie stellt ein System wissenschaftlich begründeter Aussagen zur Erklärung bestimmter Erscheinungen dar, ein schlüssiges Annahmengefüge über Ursachen und Wirkungen eines Sachverhaltes oder Phänomens. Nach dem griechischen Substantiv bedeutet theorós „Zuschauer“ oder „jemand, der ein Schauspiel

Die qualitative Inhaltsanalyse – eine Methode zur Auswertung von Interviews

Das leitfadengestutzte Interview ist eine Moglichkeit, komplexe Denkstrukturen und damit Vorstellungen von Personen zu erheben. Die Aufbereitung und Auswertung von sprachlichem Datenmaterial, das in Gesprachssituationen gewonnen wurde, wird im Folgenden beschrieben. Mit dem Verfahren der qualitativen Inhaltsanalyse wird ein systematisches, regel- und theoriegeleitetes Vorgehen vorgestellt, das Gutekriterien wie Objektivitat, Reliabilitat und Validitat sichern soll. Zur Veranschaulichung wird eine Untersuchung herangezogen, die sich mit Schulervorstellungen zur Klonierung als biotechnischem Verfahren befasst.

University students’ meta-modelling knowledge

Abstract Background: As one part of scientific meta-knowledge, students’ meta-modelling knowledge should be promoted on different educational levels such as primary school, secondary school and university. This study focuses on the assessment of university students’ meta-modelling knowledge using a paper–pencil questionnaire. Purpose: The general purpose of this study was to assess and to describe university students’ meta-modelling knowledge. More specifically, it was analysed to what extent the meta-modelling knowledge, as expressed in a questionnaire, depends on the scientific discipline to which university students relate their answer and the concrete model to which they refer while answering. Sample: N = 184 students from one German university voluntarily participated in this study. Design and methods: The questionnaire was developed based on a theoretical framework for model competence and includes constructed response items asking about the purpose of models, ways for testing models and reasons for changing models. Students written answers were first analysed qualitatively based on the theoretical framework to decide whether they expressed advanced understandings or not. Further analyses then were conducted quantitatively. Results: Findings suggest that only few university students possess an advanced meta-modelling knowledge. However, significant more students who relate their answers to the STEM-disciplines expressed advanced understandings than those who referred to social sciences or linguistics/philology. Furthermore, university students who expressed an advanced meta-modelling knowledge referred to rather abstract kinds of models in order to explain their view. Conclusions: The present study supports the assumption that meta-modelling knowledge may be situated and contextualised. Both the scientific discipline and the concrete model to which university students refer seem to be relevant item features influencing university students’ expressed meta-modelling knowledge. Implications for assessment and teaching are discussed in the article.

Interventionsstudie mit angehenden Lehrkräften zur Förderung von Modellkompetenz im Unterrichtsfach Biologie

In dem vorliegenden Beitrag werden zwei Projekte zur Forderung von Modellkompetenz bei angehenden Lehrkraften und ihren Schulerinnen und Schulern im Biologieunterricht vorgestellt. Dabei geht es zentral um den Einsatz von Modellen fur den Erkenntnisgewinnungsprozess. Im ersten Projekt wurden schwerpunktmasig Referendarinnen und Referendare und ihre Schulerinnen und Schuler gefordert. Wahrend die Referendarinnen und Referendare erfolgreich in ihrer Modellkompetenz gefordert werden konnten, gelang dies bei ihren Schulerinnen und Schulern nicht in gleichem Mase. Daher stand im Folgeprojekt die Forderung der Vermittlungs- und Diagnosekompetenz von Modellkompetenz im Mittelpunkt, diesmal bei Lehramtsstudierenden. Zentrale Methoden waren eine Fortbildung und der Einsatz der Fallmethode, die speziell zur Modellkompetenzforderung und deren Diagnose- und Vermittlungskompetenz entwickelt wurden.

Methodical challenges concerning the Draw-A-Scientist Test: a critical view about the assessment and evaluation of learners’ conceptions of scientists

ABSTRACT Students’ and pre-service teachers’ conceptions of scientists have been assessed in a variety of studies. One of the most commonly used instruments is the Draw-A-Scientist Test (DAST) which offers the advantage that no verbal skills are needed by the participants. In some studies, methodical challenges related to the DAST have been discussed; for example, the lack of drawing abilities among the subjects or the impact of the prompt itself on the drawings which lead to invalid interpretations. This study aims to evaluate the eligibility of the DAST or similar instruments to validly assess conceptions of scientists and their work. Pre-service science teachers in two cohorts (N1 = 79, N2 = 101) were prompted to draw their conceptions of a scientist, the location at which the scientist is working, and his/her scientific activity. The participants of cohort 2 were also asked to give written descriptions of their drawings and information on the conditions while they were drawing. From the results, several points of methodical criticism can be made which question the valid interpretation of DAST-drawings. Instead of using the DAST, we suggest developing and evaluating other formats, such as open-ended or closed-ended instruments which could produce a more validly interpretable assessment of individuals’ conceptions in this field.

Assessing scientific reasoning: a comprehensive evaluation of item features that affect item difficulty

The aim of this study was to improve the criterion-related test score interpretation of a text-based assessment of scientific reasoning competencies in higher education by evaluating factors which systematically affect item difficulty. To provide evidence about the specific demands which test items of various difficulty make on pre-service teachers’ scientific reasoning competencies, we applied a general linear mixed model which allows estimation of the impact of item features on the response observations. The item features had been identified during a standard setting process. Results indicate important predictive potential of one formal item feature (length of response options), two features based on cognitive demands (processing data from tables, processing abstract concepts) and one feature based on solid knowledge (specialist terms). The revealed predictive potential of item features was in accordance with the cognitive demands operationalised in our competence model. Thus, we conclude that the findings support the validity of our interpretation of the test scores as measures of scientific reasoning competencies.

Formate und Methoden naturwissenschaftsdidaktischer Forschung

Zur Verbesserung der Wirksamkeit naturwissenschaftlichen Unterrichts bedarf es fachdidaktischer Forschung! Diese Aussage findet in Zeiten von PISA grose Zustimmung. Doch auf welchen Forschungserkenntnissen basiert Fachdidaktik? Mit welchen Methoden verfolgt sie ihre Forschungsfragen?

Modelle und das Modellieren in den Naturwissenschaften

Modelle sind die zentralen Arbeits- und Hilfsmittel in den Naturwissenschaften. Einerseits werden sie als Medien fur die Kommunikation bereits bekannter Fakten eingesetzt, andererseits werden sie als Werkzeuge fur die Gewinnung neuer Erkenntnisse genutzt, wofur im Beitrag eine epistemologische, an der Funktion vonModellen und ihrer Einsatzweise zum Erkenntnisgewinn ausgerichtete Perspektive entwickelt wird. DieModellierung wird dabei als zyklischer Prozess aufgefasst, dessen Bewaltigung Modellkompetenz erfordert. Das Modell der Modellkompetenz bietet eine Strukturierung in Teilkompetenzen und Niveaustufen, die als Grundlage fur Forschung einerseits, fur Diagnose und Forderung andererseits dienen kann.