Cognitive considerations… in practice

I posted a summary last time of what best practice from cognitive science research preached about designing online resources. Putting it into practice threw up some interesting considerations. I’ve summarised these below in light of developing my first pre-lecture resource, as well as reflections stimulated by conversations about it with my colleague Claire.

The first pre-resource is for my first lecture in introductory chemistry which is based around the structure of the atom, the main components (protons, electrons and neutrons) as derived from the Rutherford model, the notion of elements and then progresses onto a discussion of isotopes, introducing the technique of mass spectrometry.  There are a lot of new terms – I counted 17 in the lecture notes* – and I derived four learning outcomes for the lecture. Both of these exclude the case studies used in the lecture, which also incorporates a demonstration.

1. The purpose of the pre-resource:

The first step was to define the main goal of the lecture, based on Norman Reid’s advice to me on this. I decided that while it didn’t encompass everything I did in the lecture, the main goal was “to describe the structure of the atom and how this leads to the definition of an element”. This would arise out of a discussion of the Rutherford experiment.  I decided to concentrate the pre-lecture resource on this goal, which threw up my first concern that the content would be very dry. I was torn between wanting to “advertise” the themes in the first lecture and rigidly focussing on the ultimate aim of the pre-resource – to introduce the viewer to some of the terminology. The resulting resource tended very much towards the latter. I suppose this makes sense, as it means the lecture can concentrate on the more interesting aspects such as applications, contexts and so on, but it was hard not to include some of this. I had to keep reminding myself that the resource was not a summary of the lecture, more a preparation for it.

2. Design

I made a simple tabbed design which uses tabs to outline the main structure – so that everything is visible at once. There are some flaws with this – for example a student who just clicks on tabs will miss two pages, although a left hand menu will highlight this.

3. Presentation of text

Keeping in mind the modality ideas discussed in the principles post, most of the text presented in the resource is spoken, with key phrases, aims and terminology given in written form. Having scripted the resource, I added the text to the notes, which can be viewed in the presentation. The first version was a bit robotic, so after reviewing other aspects, I re-recorded the audio to try to make it a bit more casual.

4. Effect on my consideration of how to deliver

Despite having taught this content for several years, being forced to choose a small amount of content meant that I really had to think again about how I introduce this topic. For example, in considering terminology, I had a dilemma about how to phrase the wording about electrons. The Rutherford model is an over-simplification, albeit a useful one, and I like to get the message across early on about its limitations, but discussing with Claire, decided to stick to the particle notion for the pre-resource, and gradually introduce the cloud model of electrons a little later through the lectures themselves. Other changes after initial review included including a definition of the atom to begin with as well as a rationale – why what was being presented was important. I have to say the exercise of distilling down to this core level has really made me think about how this content – the very basics of chemistry – can be effectively presented. One failing that I have not yet overcome is a way to integrate the content into the prior knowledge of students, although the definitions used would relate to what students who had studied chemistry before would be used to, and the lecture is based around one of the most identifiable symbols of science – the structure of the atom (which is how I start the lecture).

I also decided that some active work could be encouraged, so ask students to do some study of their own on the Rutherford experiment before the lecture – this will tie in with changes in the lecture itself on encouraging discussion, which will be discussed elsewhere in a post on scientific literacy.

5. Quiz

At the end of the resource, I had a short quiz. There isn’t much scope with this material at this stage to introduce fading, etc, so it is fairly cut-and-dry. Because I was initially going to tie this in with assessment, I did not include any feedback or right answers. The result was that it was a bit abrupt. Claire also felt the questions were tough, which they were on looking at them again, and suggested an easy starter. Therefore I decided not to include a mark for the assessment – merely to log the fact the students do them (via SCORM), and push the assessment elements to other aspects of in-class work. This freed me up to give feedback for each question (answer specific), and allow students to review the quiz and/or print off the sheet. I think this makes for a more useful learning object.

For comparative purposes, the resource before and after analysis are linked here. the next stage will be to implement them – roll on next week!

*New terms include atom, electron, proton, neutron, nucleus, alpha-particles, radioactivity, element, atomic number, mass number, isotopes, deuterium, tritium, density, atomic mass unit, mass spectroscopy, ionised.

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