When there is a large pool of applicants for an education program, job, etc. and only a few seats, one needs some selection method to select the required number from the large pool. The basic goal of a selection method is to identify those candidates who are most suited for the program/job, i.e., they are most likely to perform well in the position.

Tests are often used as an instrument in this selection process – the scores of the test provides one of the parameters in the selection. For admission to many higher study programs as well as many jobs, besides scores in some test, performance in interviews, statement of purpose, performance in undergraduate studies, etc are also used in the selection method.

When it comes to admission in colleges for undergraduate programs, although a multi-dimensional criteria can provide a better method for selection, we often use a single dimension approach: score in some admission test, or percentages in class XII. This method provides transparency and fairness, but is unlikely to be the best method of selecting the most suitable candidates.

At IIIT Delhi, we have been trying to implement multi-dimensional criteria. This note describes the evolution of the approach for entrance used by IIITD.

Initial Approach. We noted that all engineering entrance tests focused on Physics, Chemistry, Math (PCM), but did not give any importance to aptitude. In the US the SAT exam, whose scores are an important input for admission, is a general aptitude and thinking ability test.  We believed that students who are good in PCM subjects as well as aptitude are the best for a rigorous education system that we had put in place in IIIT Delhi.

Hence our initial admission criteria was – only students who have more than 80% in PCM in class XII will be eligible to apply for admission to IIIT Delhi. These cutoffs ensured that the students have a decent background in these subjects. These students had to take an entrance test, which was primarily an aptitude test examining comprehension, logical thinking, and quantitative thinking. Of the eligible students, we selected those who performed well in this test, giving us those students who did well in PCM in school, and who scored well in the aptitude test.

Data Analysis. We used data from the last few years to study how well various criteria at entrance time predict the performance of the student in our rigorous program in first year. We studied the predictive power of AIEEE, class XII marks,  and scores from our aptitude test.  In other words, we studied how strongly the performance in the entrance exams or class XII predicts performance in the first year of our CS program.  We also used data from a few well established and respected IT Institutes for the study.

What we found is interesting.  We found that the strongest correlation (of more than 0.5) with performance in IIITD (and other institutes) was of Class XII marks. That is, class XII performance is a reasonable (but not perfect) predictor of how well a student does in these Institutes.  We also found a decent correlation between the performance in the aptitude test that we conduct for entrance and the performance in the Institute. Of the three parameters we studied, the rank correlation of AIEEE with performance in the Institute was the lowest.

We further studied the impact of two main factors with decent correlations – the class XII score and score in the aptitude test.  We identified two groups of students – those who had a CGPA of 8.0 or above, and those who had a CGPA of 6.0 or below. We found that the average class XII score of the first group was almost 10% higher than the average of the second group. Similarly, we found that the average score in the aptitude test was also about 10% higher for the first group.

Refinement. The analysis indicated clearly that students who are high performers in class XII and have high aptitude scores are likely to do well in our education system. To select these students it was clear that class XII marks should be given more weight for admission.  Based on this analysis, we decided to give 50% weight to class XII marks, and 50% weight to an aptitude based entrance test.  This is the entrance method we used for 2012.  In other words, though giving importance to class XII marks for admission may a desired objective from the point of view of strengthening the school education, we gave weight to class XII marks mostly because our data showed it as the strongest predictor of performance.

Scope for further refinement. We were able to include in our selection two criteria which we thought were the most important and which could be included in a transparent manner – class XII marks and score in an aptitude test.  This year we also gingerly took some step towards including other factors – we decided to give up to 10 bonus marks for those selected for the Math or Informatics Olympiad in India. (In these two, a total of about 50 students are selected – this time none of these students completed the application process fully for IIIT Delhi.) We hope to expand this approach to find ways to include some other important factors in a transparent manner which will help IIITD select better students.