Students’ reflection on experimental design during an innovative teaching sequence with LabBook

International audienceExperimental design learning activities have been shown to foster the acquisition of scientific abilities and to favour sense-making. A teaching sequence is proposed to second year university students whose goal is to make them experience experimental design and reflect on the design process. The writing part of the students' design work is supported by a computer-based platform, LabBook, devoted to experimental design work. Students go through three experimental situations that are organized in a role-playing game. They have to design an experiment and to write the procedure that will be performed by another student. The students' reflections, collected in written reports, are analysed using a list of criteria that were designed for experimental procedures assessment. Reflecting on their successive roles as designers, technicians and silent observers, the students become aware of experimental design stakes. Observing a technician who tests the experimental procedure appears very efficient for experimental assessment and it does help students to gain assessment skills. The role-playing game makes them focus particularly on the communicability qualities of a written procedure. Since the procedure must lead the technician to collect the expected results successfully, the designers deal with communicability together with executability (feasibility, temporal and safety constraints) and data quality aims. The students point out accurately the difficulties of writing tasks, especially the balance between concise and complete or detailed description. The procedure editor of LabBook, Copex, appears very useful to them, being able to fulfil their requirements for organising and documenting a written experimental procedure. The role-playing game incites the students to deepen the scientific reflection and improves the organisation of their work. However, relevance criteria are more difficult to grab and fulfil. The experimental situations do not have the same ability to reveal these criteria to students and to make them reflect and evolve

Des environnements numériques pour étayer l'investigation scientifique et la conception expérimentale : de copex-chimie à LabBook

National audienceTwo computer environments whose aim is to scaffold inquiry learning and more specifically experimental design by learners are presented. In the first environment students are engaged in a particular task of experimental design in chemistry. In this environment, diverse strategies of scaffolding have been implemented. They are evaluated in a test with 39 first-year University students. The results show that experimental design is a complex task for students when they are working with minimal guidance and no computer environment. The outcome is a very imprecise procedure. A pre-structuring of the procedure by the computer environment forces the students to face the complexity of the experimental design but this is not sufficient for them to succeed. The students only succeed when they are provided with individualized feedbacks on the errors detected in their procedures by an artificial tutor. We mention a second computer environment, based on similar principles than the first one, that extends its area of application to any experimental activity that includes experimental design or not.Deux logiciels d'aide à la conception expérimentale au sein d'une démarche expérimentale sont présentés. Le premier encadre le travail des étudiants pour une tâche particulière de conception expérimentale en chimie. Diverses stratégies d'étayage sont implémentées dans le logiciel et testées sur la base d'une expérimentation avec 39 étudiants de Licence 1. Les résutats montrent la complexité de la conception expérimentale pour des étudiants n'ayant qu'une aide minimale sur la base de documents papier : les protocoles produits restent très imprécis. La pré-structuration de la tâche par le logiciel force les étudiants à se confronter à la complexité de la conception expérimentale, mais ne leur permet pas de mener à bien leur tâche. Seul l'apport de rétroactions sur les erreurs identifiées dans les protocoles leur permet d'aller au bout de la tâche de conception expérimentale. Un second logiciel est évoqué, qui reprend certains principes du premier, mais élargit son domaine d'utilisation à toute séance expérimentale, qu'elle comprenne ou non de la conception expérimentale

Students’ reflection on experimental design during an innovative teaching sequence with LabBook

International audienceExperimental design learning activities have been shown to foster the acquisition of scientific abilities and to favour sense-making. A teaching sequence is proposed to second year university students whose goal is to make them experience experimental design and reflect on the design process. The writing part of the students' design work is supported by a computer-based platform, LabBook, devoted to experimental design work. Students go through three experimental situations that are organized in a role-playing game. They have to design an experiment and to write the procedure that will be performed by another student. The students' reflections, collected in written reports, are analysed using a list of criteria that were designed for experimental procedures assessment. Reflecting on their successive roles as designers, technicians and silent observers, the students become aware of experimental design stakes. Observing a technician who tests the experimental procedure appears very efficient for experimental assessment and it does help students to gain assessment skills. The role-playing game makes them focus particularly on the communicability qualities of a written procedure. Since the procedure must lead the technician to collect the expected results successfully, the designers deal with communicability together with executability (feasibility, temporal and safety constraints) and data quality aims. The students point out accurately the difficulties of writing tasks, especially the balance between concise and complete or detailed description. The procedure editor of LabBook, Copex, appears very useful to them, being able to fulfil their requirements for organising and documenting a written experimental procedure. The role-playing game incites the students to deepen the scientific reflection and improves the organisation of their work. However, relevance criteria are more difficult to grab and fulfil. The experimental situations do not have the same ability to reveal these criteria to students and to make them reflect and evolve

Modèle de construction d'un EIAH pour une activité de conception expérimentaleBuilding model of an EIAH for an experimental design activity

RésuméNous présentons et discutons l'utilisation de modélisations praxéologiques dans une activité de conception d'expériences en sciences expérimentales. Nous avons modélisé la tâche de l'élève de production d'un protocole expérimental en couplant des « types de tâche de conception » au modèle praxéologique de la manipulation. Ce modèle enrichi nous a servi pour concevoir un Environnement Informatique pour l’Apprentissage Humain (EIAH), TitrAB, dédié à la conception d’expériences de titrage en chimie, à la fois dans la sélection des tâches de l’activité travaillées dans TitrAB ainsi que dans la production de rétroactions automatiques.Mots-clés : Protocole expérimental, Environnement Informatique pour l’apprentissage Humain, Rétroactions automatiques.AbstractWe describe and discuss the use of the praxeological model in an experimental design activity in experimental science. We model the student’s task in the production of an experimental procedure, by introducing “Conception Task Types” to the praxeological model of the experiment. This extended model was used to design TitrAB, a software dedicated to an experimental design situation in Chemistry, in two ways: the selection of the activity tasks in TitrAB and the production of automatic feedback to the student’s protocol.Keywords: Experimental procedure, Software dedicated To an experimental design situation, Automatic feedback

Introduction d’une plateforme numérique dans un dispositif APP – quelles adaptations, quelle influence sur la coopération/collaboration étudiante ?

Nous présentons dans cet article une analyse des gains constatés et des difficultés rencontrées lors de l’introduction d’une plateforme numérique dans un dispositif d’apprentissage sous forme d’Apprentissage Par Problèmes (APP). L’étude croise le bilan des enseignants, des retours d’étudiants et des traces d’activité enregistrées sur la plateforme. Une attention particulière est portée à l’influence de la plateforme sur la coopération/collaboration entre étudiants

The Fpg/Nei Family of DNA Glycosylases

During the initial stages of the base excision DNA repair (BER) pathway, DNA glycosylases are responsible for locating and removing the majority of endogenous oxidative base lesions. The bifunctional formamidopyrimidine DNA glycosylase (Fpg) and endonuclease VIII (Nei) are members of the Fpg/Nei family, one of the two families of glycosylases that recognize oxidized DNA bases, the other being the HhH/GPD (or Nth) superfamily. Structural and biochemical developments over the past decades have led to novel insights into the mechanism of damage recognition by the Fpg/Nei family of enzymes. Despite the overall structural similarity among members of this family, these enzymes exhibit distinct features that make them unique. This review summarizes the current structural knowledge of the Fpg/Nei family members, emphasizes their substrate specificities, and describes how these enzymes search for lesions

Characterizing the Experimental Procedure in Science Laboratories: A preliminary step towards students experimental design

Supported by the French Ministry of ResearchInternational audienceMany studies have stressed students' lack of understanding of experiments in laboratories. Some researchers suggest that if students design parts of, or entire experiments as part of an inquiry-based approach, it would overcome certain difficulties. Experimental design implies to write a procedure. The aim of this paper is to describe the characteristics of a procedure in science laboratories. As a starting point, this paper proposes a model in the form of a hierarchical task diagram that gives the general structure of any procedure. This model allows both analysing existing procedure and designing new inquiry-based approach. The obtained characteristics are further organized into criteria that can help both teachers and students assess a procedure during and after its writing. These results were attained through two different sets of data. First, the characteristics of procedures were established by analysing laboratory manuals. This allowed defining the organization and type of information in procedures in educational context. This analysis revealed that students are seldom asked to write a full procedure, but sometimes have to specify tasks within the procedure. Secondly, iterative interviews were undertaken with teachers. This led to the list of criteria to evaluate the procedure