1. WELCOME Presentation slides can be downloaded from: http://www.rivervalleypri.moe.edu.sg

2. ? ? ? PSLE SEMINAR PSLE T-Score Explained

3. OUTLINE • PSLE is a placement exam • What is the PSLE Aggregate SCORE? • Why is T-Score used? • Definition & Calculation of T-Score • Questions about T-Score

4. PSLE - a placement exam • Need to reflect the relative achievement level of pupils within their peers. • Places pupils into different courses according to their academic ability • Enables posting to secondary schools by merit and as far as possible into a school of their choice.

5. What are these scores? Are they raw scores? What is PSLE Aggregate Score? It is a sum of scores.

6. The PSLE Aggregate Score • incorporates performance of pupils in all 4 subjects • allows pupils to be ranked fairly

7. NO ! Can raw scores be used?

8. Why Not? • Different subjects have different levels of difficulty • So are the spread of marks from the average mark, i.e. the standard deviation (spread = standard deviation)

9. Narrow Wide MEASURE OF S P R E A D

10. H U R R A Y ! I scored 85% in both English and Mother Tongue ! DOLLY

11. Her performance in MT is very close to that of other pupils 85% • She did much better in EL as compared to other pupils EL MT EL ave = 60 MT ave = 80 Dolly scores 85% in both EL and MT 0 100

12. Transformed Score or T-Score A need for standardisation of the raw scores

13. EL 85% 85% ave = 60 ave = 80 50 T-Score MT T-Score converts average mark of each subject to a common score of 50 points. It also converts other marks taking into consideration the extent to which they differ from the average and the size of spread of the marks around the average

14. What is T-Score? • It gives the relative position of a pupil’s performance as compared to the performance of all the other pupils in that subject • The raw mark obtained in the exam only shows how good the pupil is in that subject, not how good he is as compared to others

15. How is T-Score calculated for each subject? (X - Y) = + T 50 10 Z where X: pupil’s mark for the subjectY: average mark (mean) scored by all pupils Z: spread of marks around the average mark (standard deviation)

16. (50 - 68.0) T = 50 + 10 14.0 = 37.14 Example: • Pupil’s mark (X) in exam = 50.0 • Average mark (Y) scored by all pupils = 68.0 • Spread of marks (Z) around the average mark (Y) = 14.0

17. How is the Aggregate Score calculated? By adding the T-Scores of the 4 subjects

18. Example: Subject Total Mark T-Score EL1 200 105 34 CL2 200 152 51 Maths 100 67 53 Science 100 58 47 Aggregate: 185

19. Finally, all pupils are ranked according to their Aggregate Scores

20. T-SCORES & GRADES: Is it possible for a pupil with 3A* and 1A to be ranked lower than another pupil who has only 1A* and 3As? Yes, it is possible

21. Aggregate T-Score: 246 249

22. Expected Mean Aggregate Score by Class 2009

23. Estimation of Aggregate Score