Teacher support material

Wednesday 22 July 2015

(Image © IBO)

Damned if you do, dammed if you don’t. This is the situation that the IB sometimes finds itself in when it comes to providing Teacher Support Materials. When there are changes to the programme teachers quite naturally want some examples of marked work so they can place the correct emphasis on their teaching. The problem the IB has is that often for new programmes there are no genuine examples to form the basis of the TSM. In an attempt to support the teachers they then have to use manufactured examples instead of genuine student work submitted for internal or external assessment. At the same time the new criteria have not really been ‘bedded in’ so sometimes the marks awarded and comments made on the work can seem strange. This happened for the IA exemplars for the old programme when it was newly introduced and seems to have happened again for the new programme. Some teachers have already carried out the Individual Scientific Investigation with their students but most will be leaving it to the second year so it is only now that the TSM on IA is beginning to be looked at carefully by most teachers. Currently there are ten exemplar investigations together with marks and comments. These were not written with the existing criteria in mind and some problems have emerged.

During the past year and a half I have run several workshops on the new programme totalling more than 200 participating IB chemistry teachers from many different countries. About 140 of these were experienced IB teachers with the remainder being new to IB teaching. After covering all the criteria etc. I have given them the first exemplar on ‘Factors affecting the melting and boiling points in organic homologous series’ as a marking exercise. Normally with marking exercises where the work is genuine students’ work the participants’ marks scatter around the official IB mark with the mean being pretty close to the actual mark. Repeatedly in all the workshops this has not been the case with this exemplar. The IB awards a mark of 22 out of 24 whereas the mean from participants is between 14 and 15 out of 24. Clearly something is amiss. In discussions afterwards several points emerge but the main one is that no processing at all is carried out. The student merely plots the boiling point (or melting point) against molar mass for different homologous series and even makes a mistake in quoting the uncertainty as ± 0.5 oC whereas in the data table the uncertainty is given as ± 1 oC. The conclusion reached can just as easily be obtained directly from the data table with no need for the graph at all and yet 5 out of 6 is awarded for ‘Analysis’. In the past the lack of processed data would either have been marked down severely or, if no processing is really possible, as in this case, teachers would have been told that the experiment is not suitable for assessing this criteria.

In ‘essay’ work such as this there are bound to be differences in the interpretation and application of criteria so one would expect some variation in the marks but for several of the TSM IA exemplars there is considerable concern. One of the problems teachers had with the old programme (for last examination in November 2015) was feeling that the moderation of their students’ work was not consistent. One would hope that this will improve for the new programme. In the meantime I suggest two things. One Is that teachers use the TSM material in the spirit that it is intended but accept that it is not perfect and secondly, once genuine student work has been received next May, the IB replaces the existing TSM material with some tried and tested examples.


Tags: TSM, IA, workshops


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