Algorithm for inferring the offer chances of JUPAS programmes

“Offer chance” indicates the possibility of obtaining an offer from the JUPAS programme. It is estimated by calculating the score from the exam results entered in “My HKDSE”, according to the scoring system and subject weightings of the programme, and comparing with the admission scores in the past years. More the star symbols, higher is the possibility of obtaining an offer. The highest possibility is indicated by 5 stars. Interview, test and other non-academic performances are not considered in the estimation. The estimated possibilities are for reference only, and are regardless of the actual offer results. We do not take any responsibility for the accuracy of the offer possibility estimation.

Step 1: For each JUPAS programme, estimate the cumulative curve of admission score from the data announced by the institution. The institutions usually announce the admission score information in terms of quantiles, e.g. upper quantile, median, lower quantile. BigExam has well designed a sigmoid function to mathematically model the cumulative curve of admission scores. The parameters in the function is specifically adjusted for each programme in order to make the curve pass through the given quantiles. For example, the quantiles of the admission score are:
Upper quartile: 21.5
Median: 20
Lower quartile: 19
After adjusting the parameters, the cumulative curve is as shown below.

If there are only two quantiles are available for a programme, e.g. median and lower quantile only, the sigmoid function will be adjusted to pass through the two quantiles. If there is only an average score for a programme, the cumulative curve will be approximated by big data analysis with reference to the admission scores of other programmes. If there is no admission score in the past years provided, usually the case of new programme, BigExam will estimate the admission score and choose another programme with the closest admission score as reference.

Step 2: According to the scoring scheme of each programme, calculate the score from the result entered in "My HKDSE" by the user. The weightings of the specific subjects have been included in the calculation. Some of the institutions indicate the subjects with heavier weightings without the actual values. In this case, BigExam defines the values of the weightings as listed below.

InstitutionHeavier weightingEven heavier weighting
CUHK1.6
EdUHK1.5
HKU1.52.3

Step 3: Using the score obtained from Step 2, look up the corresponding quantile from the cumulative curve in Step 1. Higher the value of the quantile, higher is the chance of receiving offer of the programme. The same algorithm is applied to the admission score of each past year to obtain a series of quantiles. The weighted mean of the series of quantiles is used as the final estimation of offer chance. The offer chance is expressed in 6 levels. The definition of the levels are as follows.

Offer chanceWeighted quantile range
Slim< 8%
Little8% ‒ 18.75%
Try it out18.75% ‒ 37.5%
Medium37.5% ‒ 62.5%
High62.5% ‒ 87.5%
Strong> 87.5%

If user’s result does not meet the minimum entry requirements of a programme, offer chance estimation will not be provided for that programme.