In the developmental testing of a design, you are testing for the unexpected: for unexpected wrong responses, unexpected interfering responses and unexpected attitudes of learner and teacher (if one is involved). These things are ‘unexpected’ because with the help of the four referents and the protocol for working out a design, you have done your best to avoid unwanted results. But in this respect, ‘all that glitters is not gold’. You must expect the unexpected. The symptom that all is not what it should be is an unexpected low rating on one or more of the elements in the Emax Vmax Lmax E’max criteria.
Table 6: A video presentation test result
| Effective | Valued | Liked | Efficient |
| + | + | + | + |
| ++ | ++ | — | ++ |
| + | + | + | + |
| ± | + | + | + |
| ± | ± | ± | + |
| + | + | + | + |
| + | + | ± | + |
| + | + | _ | ++ |
| + | + | _ | + |
In Table 6 you can see the results from a test of the reaction of ten learners to a video presentation. The film was 20 minutes long and in colour. It aimed to teach the set up of an experiment in physiology on the effect of chemical and electrical stimuli on the heart rate of an anaesthetized frog. Set up of the experiment involved anaesthetizing the frog, opening its chest to expose the heart, and the attachment of a measuring device to the exposed heart. The surgical operation is a delicate one. Mistakes are easily made. These can lead to bleeding and the need for intervention by an experienced laboratory teacher. Irreparable damage to the heart can also occur. If the damage is irreparable, the set up must be begun all over again with a second anaesthetized frog. The class for whom the teaching film was made consisted of 70 students. What do you make of the results in the development test group (Table 6)?
One student has quite different views about the teaching quality of the film from the rest. What would you do with such a contradiction? Anything? What do you think is accounting for a consistently low rating on ‘liking’ the film? Would you think the film is didactically a success?
The questions above are the sort of questions which will challenge your skill as a diagnostician and trouble-shooter when you get back the results from a developmental test of a course or lesson or of a single S-R event. You will need your intuition, creativity, and logical thinking to tell you what to do. When things turn out to be very unexpected you will need the courage to go back into your think tank and re-think the whole design. When things are relatively good (the majority rating high and a minority rating low) you have to decide how to make any necessary changes at a minimum cost. Sometimes this will take a lot of didactic cunning. The chances are that you will already have invested quite a lot of time and energy in thinking up and working out the design.