Letters - March 2008

Fingers on buzzers...

Readers may be interested to know that the use of electronic voting systems (EVS) in the teaching of chemistry is proving to be a hit with staff and undergraduates at the Universities of Reading and Southampton. Chemistry students are using these 'zappers' to take part in short quizzes, incorporated into lecture presentations, that are designed to encourage interactions and test understanding.  

At Reading 96 per cent of students on a foundation-year chemistry course said they enjoyed using EVS and 87 per cent said they felt that the activities helped them to learn. Students at Southampton commented that the system 'gives everyone a chance to interact and see how they are doing in relation to everyone else' and encourages them to 'actively think rather than just listen'.  

The EVS software can instantly produce a graph of responses from which lecturers can gauge comprehension and quickly correct common misconceptions, and students can get valuable feedback on their own understanding. Operated in non-anonymous modes, EVS can be used for summative assessment. Students' responses are marked by the software, which means staff can devote more time to providing feedback. The students' handsets are easy to use and the software is straightforward, allowing questions to be easily incorporated into PowerPoint presentations. 

Both chemistry departments are now also using EVS to enhance their schools' outreach activities. At a recent Chemistry Week event Reading invited teams of local GCSE students to debate whether genetically modified sprouts should be on the school menu. Using the EVS students' opinions were canvassed before and after the debate, and the winning team chosen on the results of the 'swingometer'. Staff at Southampton have used EVS during visits to schools and colleges to encourage all students to contribute to discussions. The positive response from teachers suggests that EVS might be of value in schools as well as universities. 

Reading and Southampton have developed the use of EVS in the teaching of chemistry thanks to support from the Royal Society of Chemistry (RSC) via the Chemistry for our future (CFOF) programme. We have shared our experiences with other departments in our universities and hope that staff in other chemistry departments will try their hand with EVS, if they aren't doing so already.  

Gan Niyadurupola, CFOF project officer at the University of Reading
David Read, school teacher fellow at the University of Southampton

In response...

In his recent review of Science education for gifted learners (Educ. Chem., 2008,45 (1), 31) Tim Jolliff suggests that while the book will make readers 'think quite deeply about your science teaching', it will only appeal to a minority of science teachers. Jolliff gives two main reasons for this: the language used, and a theoretical rather than practical focus. The reviewer is of course entitled to those views, which I am sure have been reached after due consideration. However, as editor of the book I would like to ensure that readers are not left with a misunderstanding of the nature of the book. 

In setting up a seminar series for science teachers in the Cambridge area, we were informed by colleagues in schools who wanted ideas to challenge their most able students and to develop their classroom practice. Teachers attended and contributed to our meetings (on Saturday mornings), and even helped write some of the chapters in the book. 

Jolliff is correct in suggesting that the book does look to set out the 'big picture', something that we felt was largely missing from the literature readily available to teachers. However, I think it is misleading to suggest that 'making a connection between these theoretical principles and what happens in our classrooms is left largely to the reader'. While a few of the chapters do discuss general background topics, most of the contributions are grounded in classroom practice, and offer examples from science lessons in schools or from extra-curricular enrichment activities that the contributors have been involved in. 

It may be that the reviewer's comments relate to the absence of specific lesson plans or student worksheets in the book. Teachers looking for classroom materials could try instead Enriching school science for the gifted learner (available from the Gatsby Science Enhancement Programme), or Jolliff's Chemistry for the gifted and talented, published by the Royal Society of Chemistry.  

Science education for gifted learners aims to highlight useful ideas and approaches, and to illustrate these with real examples from practice in typical classrooms. I hope that any teachers looking for a book to inform their work with their gifted students will be prepared to leaf through a copy and draw their own conclusions about the extent to which the text links with classroom practice, before deciding whether or not to buy the book or recommend it to colleagues. 

Keith Taber, University of Cambridge

Practical work

I was greatly heartened to read the excellent Endpoint article by Peter Borrows, What is practical work? (see Educ. Chem., 2008, 45 (1), 32). Working in a large inner-city sixthform college, we find our students arrive with very poor practical skills. The temptation is for teachers to refrain from allowing students to do test-tube reactions and teach everything by video, demonstration or animation. This approach can be justified by the idea that if the students do practical work, they get the 'wrong answer', it takes too long and produces a lot of mess. Ultimately, however, this does not give them the practical skills they need and deserve. Getting 'wrong answers' is part of the learning (and fun?). It is simply not the same to watch. 

In these days of emphasis on interactive teaching methods and kinaesthetic learning styles, surely practical work of the test-tube kind should form the basis of many chemistry lessons. 

Pauline Winn, Stockport

Relativistic effect

In response to Dr John Emsley's answer to the Q&A question on the physical properties of gold and mercury the generally accepted explanation of the relativistic effect experienced by the 6s electron says that the velocity of the electron near the nucleus is very large, approaching the speed of light (c), and therefore the effective mass of the electron becomes large. This causes the radius of the 6s orbital to shrink; radius is proportional to 1/mass. The attraction between the electron and the nucleus is electrostatic in nature, not gravitational. The mass of the nucleus is not involved. The large positive charge of the nucleus (Z) causes the effect. A good description of this relativistic effect is given by Pekka Pyykkö (Chem. Rev., 1988, 88 , 563) and also by L. J. Norby (J. Chem. Educ., 1991, 68, 110). 

Michael Laing, University of KwaZulu-Natal