B. Demetriou and J. R. Parsonage

Thames Polytechnic London SE18 6PF. England I Chemistry for Electrical Engineers

A study of chemistry as an ancillary subject is included in stammering and stuttering; objective marking. Some of these a wide variety of undergraduate physical science courses. The criticisms may he justified; however as a result of our first success of this tvoe of course is freouentlv affected hv three attempts at oral assessment, and the favorable response of the constrainm: ~ack'of staff and student mkvation; abroad students, we would encourage others to try it. spectrum of student backgrounds; and the method of assess- For eachsection of the nurse, a hank of questions was de- ment.'' In an attempt to overrume some of these problems signed; these included some questions poorly answered on the we have developed an inteerated. self-contained (includine series of short answer test papers. Each student was asked one assessment) che&try cbu&, and we have demonstrated thai question from each bank-two question programs for student oral assessment can he used as a terminal assessment meth- groups A and B are shown below. od. This svstem nrovides enoueh securitv and flexihilitv, and

Course Structure yet enough strccture for the Gforma&e of the stud& to he comnared. On the basis of the student's answer to each of

The time allocation for thiscourse was 20 hr at 1 hrlwk; we the banked questions, the interview was expanded to probe redured the content of the course to a minimum, and divided the student's knowledee and understandine. Their oerfor- i t into four main topics entitled

1) Atomic structure, periodic table and valency 2) Acids and bases 3) Electrochemistry and corrosion 4) An introduction to polymers

Each topic was taught by a series of lecture demonstrations (BD), and was accompanied by a detailed handout. One of us (JRP) took careful notes during these lectures (four for topic one), and these were used as the basis for a revision seminar on the fifth week, followed hy a short answer k t the following week. This procedure was repeated for the other topics and the whole course was examined by an oral examination. We had originally intended that oral assessment would he used exclusi~ely; not only was this impractical because of time constraints, hut i t seemed desirable to have some written as- sessment connected with this course.

Oral Assessment This form of assessment has received little attention in the

undergraduate science courses in the United Kingdom. I t is reasonably common for an external examiner of an under- graduate course to i n t e ~ e w students placed on the borderline between two classes of degree as a result of the traditional "finals" examination. The PhD "viva voce" examination is also a well established practice, hut the oral used as a re- placement for a traditional form of assessment is rare. As ?'hompson3 has found, i t is used more in Europe than the United Kinedom. althoueh some ouite detailed work has been carried o u t a t s&ondar; level here.4 The oral examination allows the student to exoress himself on chemical topics and apply his ideas to his ma.in discipline which is the desired aim of most ancillary courses. It allows the examiner to be flexihle in his approach; and allows an assessment method to be used in a teaching mode. Why then is i i not used more often? Objections to oral examinations include: personality clashes hetween examiner and examinee; student difficulties such as

mance was marked out of ten by the examker and the oh- server: the tests (taw recorded with the student's permission), were marked aZa& a t a later stage. The first and second markines were re~roducihle. and we are satisfied that the systemwas capabie of separating students into a rank order of ability. We have noticed that the rank order correlation coefficie& between the written and oral assessments are low, indirating that a variety of abilities were being measured.

The use of short intermittent assessment aids the rapid identification of student problems; the students seemed un- concerned with the large number of assessments, rather they seemed to resoond to the stimulus to learn the material as it was presented. A final oral examination acts not only as an assessment, hut it also allows any misconceptions to he clar- ified before the student proceeds to further study. The structure of this course enables assessment to he used as a motivating, feedback device.

Group A

What do you understand by the periodic table? Explain the bonding in an ionic compound. Give an example of an acid and explain what is meant by neutralization. How would you use chemicals to produce an electric current?

Group B

Why are the noble gases so called? Distinguish between the terms ionic and covalent. What is meant by pH? Oxidation is the reverse of reduction-comment on this

' Prosser, A. P., The Vocational Aspect of Educ., XXII, (51), 19, (1970).

Parsonage, J. R., In "The Communication of Chemistry." The Chemical Society, London, 1974, p. 4.

Thompson, J. J., Educ. in Chern., 9,225 (1972). 'Brown, P., Hitchman, P. J., Yeoman, G. D., "Schools Council

Examination Bulletin No. 21, C.S.E." Metheun, London (1971).

Volume 54, Number 4, April 1977 1 221