scholarly journals Articuler des analyses qualitatives et quantitatives pour mieux comprendre l’activité in situ : deux études en éducation physique et en sport

2021 ◽  
Author(s):  
Gilles Kermarrec ◽  
Ghada Regaieg ◽  
Rebecca Clayton-Bernard
Keyword(s):  
Prise De Décision ◽  
Méthode Mixte ◽  
Analyse Statistique

Pour appréhender des phénomènes complexes in situ, des chercheurs adoptent des méthodes qualitatives. Ce chapitre présente une méthode mixte articulant des analyses qualitatives et quantitatives : (1) une catégorisation qualitative empirique ou théorique ; (2) le codage quantitatif de l’activité ou le recueil de données quantitatives sur l’activité ; (3) une analyse statistique croisant des variables catégorielles et des variables numériques. Deux études sur l’apprentissage et la prise de décision sont présentées pour illustrer comment une méthode mixte a permis : (1) de valider la catégorisation d’unités de sens ; (2) d’évaluer la puissance discriminatoire des catégorisations qualitatives. Les méthodes mixtes pourraient ainsi contribuer à en améliorant la compréhension de l’activité in situ des pratiquants ou des intervenants.

scholarly journals Évaluation formative et autorégulation des apprentissages des élèves : propositions méthodologiques pour l’analyse de processus in situ

2019 ◽  
Vol 41 (2) ◽  
pp. 131-162 ◽  
Author(s):  
Céline Lepareur ◽  
Michel Grangeat
Keyword(s):  
Analyse Statistique ◽  
Mise En Œuvre ◽  
Evaluation Formative

La recherche concerne l’étude des effets de différentes modalités d’évaluation formative sur l’autorégulation des apprentissages des élèves, dans le cadre de l’enseignement scientifique fondé sur l’investigation. Des indicateurs nous permettant d’analyser les processus in situ sont construits et deux situations d’enseignement sont comparées. La première porte sur l’évaluation formative que les enseignants mettent en oeuvre dans leur pratique quotidienne. La seconde concerne l’évaluation formative mise en oeuvre par les mêmes enseignants l’année suivante, à la suite d’un travail réflexif avec des chercheurs. Après avoir confirmé, par le biais d’une analyse statistique, que les enseignants mettent en oeuvre différentes modalités d’évaluation formative d’une année à l’autre, nous décrivons les pratiques évaluatives des enseignants et leurs effets sur les élèves. Nous observons un meilleur équilibre dans l’usage des différentes modalités d’évaluation formative par les enseignants dans la seconde situation ainsi qu’une autorégulation plus efficace des comportements des élèves dans la tâche proposée.

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Structural Studies on Mitotic Spindle Fibres

1978 ◽  
Vol 36 (3) ◽  
pp. 615-626
Author(s):  
J.R. Mcintosh
Keyword(s):  
Chemical Composition ◽  
Mitotic Spindle ◽  
Structural Studies ◽  
Mitotic Apparatus ◽  
Chemical Studies ◽  
Medical Interest ◽  
Spindle Fibres

The mitotic apparatus is a structure of obvious biological and medical interest, but it has proved to be a difficult cellular machine to understand. The chemical composition of the spindle is only slightly elucidated, largely because of the difficulties in preparing useful isolates of the structure. Chemical studies of the mitotic spindle have been reviewed elsewhere (Mcintosh, 1977), and will not be discussed further here. One would think that structural studies on the mitotic apparatus (MA) in situ would be straightforward, but even with this approach there is some disagreement in the results obtained with various methods and by different investigators. In this paper I will review briefly the approaches which have been used in structural studies of the MA, pointing out the strengths and problems of each approach. I will summarize the principal findings of the different methods, and identify what seem to be fruitful avenues for further work.

Electron Probe Analysis of Muscle

1982 ◽  
Vol 40 ◽  
pp. 398-401
Author(s):  
A. V. Somlyo ◽  
H. Shuman ◽  
A. P. Somlyo
Keyword(s):  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Resting State ◽  
Binding Sites ◽  
Electron Probe ◽  
Frog Skeletal Muscle ◽  
Electron Probe Analysis ◽  
Probe Analysis

Electron probe analysis of frozen dried cryosections of frog skeletal muscle, rabbit vascular smooth muscle and of isolated, hyperpermeab1 e rabbit cardiac myocytes has been used to determine the composition of the cytoplasm and organelles in the resting state as well as during contraction. The concentration of elements within the organelles reflects the permeabilities of the organelle membranes to the cytoplasmic ions as well as binding sites. The measurements of [Ca] in the sarcoplasmic reticulum (SR) and mitochondria at rest and during contraction, have direct bearing on their role as release and/or storage sites for Ca in situ.

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