Using lecture demonstrations to promote the refinement of

Chemistry Education Research and Practice, 2007

Novices often lack the descriptive knowledge of phenomena that is the basis for an expert's interpretation of scientific concepts. Such lack of knowledge may lead to poor conceptual understanding, and misinterpretation of these concepts. Lecture demonstrations can provide essential experiences that serve as a context for discussion of over-generalized or oversimplified concepts. The design of such demonstrations starts from surveying the limited knowledge base of the student, followed by exploration of the richness of relevant contexts of the expert, and identifying key instances that can serve as meaningful discussion topics. An example of the design of a demonstration set for teaching solvent miscibility and its relation to intermolecular interactions is given, followed by results of its application in two different presentation modes: confrontation (aims at generating a conflict with existing conceptions) and refinement (aims at promoting differentiation and contextualization of scientific concepts). The students' involvement in peer discussion, associated with these demonstrations, is evaluated by considering the distribution of students' predictions. [Chem.

Proceedings of the Australian Conference on Science and Mathematics Education, 2013

Demonstrations are commonly used in Chemistry lectures to illustrate chemical phenomena and as entertainment. Interactive lecture demonstrations have been introduced into first year undergraduate classes which more deliberately connect the demonstration with the course content. Through the development of worksheets, students are actively engaged with predicting, observing and explaining the results of the demonstration. Evaluation of this approach through surveys and class observation suggest that students found it engaging and effective for their learning.

1997

Bibliothaue nationaie du Canada Acqwsitions et services bibliographiques 395. rue Welltngtm Ottawa ON K l A ON4 Canada Your h1e Vorre reference Obr hie Norre retdrence 'The author has granted a nop-L7auteur a accorde une licence non exclusive licence allowing the exclusive pernettant a la National Library of Canada to ~i&othi.~udnationale du Canada de reproduce, loan, dstribute or sell reproduire, priter, dstribuer ou ' copies of this thesis in microform, vendre des copies de cette these' sous paper or electrontc formats. la forme de microfiche/film, de' reproduction sur papier ou sur format electronique. The author retains ownership of the L7auteur conserve la propriete du copyright in h s thesis. Neither the droit d7auteur qui protege cene these. thesis nor substantial extracts from it Ni la these ni des extraits substantiels may be printed or othenvise de celle-ci ne doivent itre imprimes reproduced without the author' s ou autrement reproduits sans >.on permission. autorisation.

Journal of Chemical Education, 1998

Journal of Science Education and Technology, 2004

Different visualization techniques have been used for teaching chemistry concepts. Previous studies have shown that when molecular animations and video demonstrations are used, students seem to better correlate all three levels of representation: macroscopic, submicroscopic, and symbolic. This thinking process allows the students to improve their conceptual understanding and ability to create dynamic mental models. In this study, general chemistry students viewed three experiments involving dynamic fluid equilibrium in a graphic design, a video demonstration, and a molecular animation. The study investigated whether video demonstrations or particulate animations helped the students' conceptual understanding, and if the order of visualizations (video or animation first) produced any differences. Students showed improvement after each visualization. Surprisingly, there was significant improvement in responses between the first and second visualization. This work shows the importance of combining both types of visualizations, but it does not indicate a preference toward a specific order.

This research investigated the teaching of concrete chemical concepts and procedures to beginning chemistry students. Data were collected for this study from students enrolled in a university-level course for nonscience majors (n=171). In the topic studied, chemical bonding, four different teaching strategies were investigated: remediation of basic concepts, bridging explanations, worked examples, and student-initiated discussions of concepts. Statistical analyses were used to compare each teaching strategy against the exam score on chemical bonding. Results of these comparisons indicated that none of the strategies were superior (p>.05); however, each had notable strengths and weaknesses. The students in the remedial group had the worst attendance, but scored the highest of all treatment groups on the bonding exam. Students in the worked examples treatment group had the best attendance, but derived the least benefit as indicated by the smallest increase between pre-and posttests and the weakest performance on the bonding exam.

Journal of Chemical Education, 1977

The attainment of an effective level of laboratory instruction poses many interesting challenges to the instructor in that students need to be evaluated on such diverse matters as manipulative skills, data aquisition, and interpretive abilities. The most important characteristics of any laboratory exercise lie in the student's ability to successfully carry out the procedure while gaining a clear understanding of the theory on which the experimental procedure is based. To simplify the transition that the chemistry student must make-in putting classroom theory into laboratory practice-pre-laboratory instruction has become an important element of undergraduate chemistry.

Journal of Chemical Education, 2008

EURASIA Journal of Mathematics, Science and Technology Education, 2016

In this study we explored whether the use of teachers' demonstrations significantly improves students' understanding of redox reactions compared with control group counterparts who were not exposed to the demonstrations. The sample consisted of 131 Israeli 8th graders in middle schools (junior high school). Students' attitudes and achievements as well as their understanding of redox and electrolysis were assessed by administering a questionnaire that investigated their attitudes (perceptions) towards a demonstration in chemistry. The findings showed that the experimental group's achievements and understanding of the subject were statistically significantly better than those of their control group counterparts.

Tidsskrift for Den Norske Laegeforening, 1999

Sammendrag Den høye rekru eringen av røykere blant unge mennesker er y erst bekymringsfull. Gro Harlem Brundtland har erklaertkrig mot røyken, og i USA snakker president Bill Clinton om en røykeepidemi blant ungdom. Kanskje er det ingenrøykeepidemi blant norsk ungdom, men antallet unge røykere synes å øke. Hvorfor er helseinformasjonen så lite effektiv?Det skorter neppe på viten. Men den moderne kulturen er i ferd med å miste en holdning som er viktig for å omse eviten om helseskadene i handling. Gjennom tiår har vi svekket en tanke som kanskje mer enn noen annen vil kunnemotivere den enkelte til å ta ansvar for egen helse: At vi har moralske plikter overfor oss selv.