CEM IBE Student Prediction Reports The American International School of Johannesburg Exam Year 2014 All Students (29 January 2013) Explanation of the Predictions. Predictions from GCSE Points Grade 3.6 4 : : : :
Subject IBH - Biology : :
Predictions from Test Points Grade 4.7 5 : : : :
The prediction table at the top of each page displays predictions calculated from the regression equation for each subject. In this process grades are converted to points and a regression (or 'Trend') line is computed. The predicted points thus represent the point score attained on average by all students of the same ability in the previous summer's exam results.Some students will have got more points than this and some less. The predicted points are then converted to the nearest whole grade. Predictions are given using Average GCSE as an indicator of ability and also using an alternative baseline test (either the TDA or the Computer Adaptive Test) where scores are available. A set of probability graphs ('Individualised Chances Graphs') is shown below the table of predictions, thus:
Probability
Probability
GCSE - IBH Biology - Baseline Test
26 20
18
12 1
5
N
1
26
12
3
4
5
6
14
12 6
2
22
20
7
6 N
1
2
3
4
5
6
7
The blue bars on these graphs show the probability of the student achieving each grade in that subject. The graph on the left uses the average GCSE score as a measure of ability, and the graph on the right uses the baseline test (TDA or Computer Adaptive) if sat. The black bar shows the expected result (mean grade) for that student. In this example the student is predicted 3.6 points (see table above) which converts to a grade 4. From the chart on the left it can be seen that the most likely grade (modal grade) is a 4 with a 26% probability of achieving this grade. However there is also a good chance that the student will get some other grade - in fact there is a 38% chance of getting lower than a 4 and a 36% chance of getting higher than a 4. Thus using the modal value (the highest bar on the chart) as a predictor does not reflect the possibility of achieving other than a 4 (74%) and so it is more appropriate that the mean predictor is used (the black bar) to reflect all possibilities for the student. This mean or expected result will agree closely with the prediction displayed in the table. The data presented in this report is based upon the information received by CEM IBE upon registration of the students and was generated on 29 January 2013. Any subsequent changes to the students' subjects will not appear in this report. If predictions are needed for new subjects, these can be generated using the PARIS software.