While working through our application and admission data, we see quite a few applicants who have done a required course at summer school, especially among Ontario residents. (It doesn’t seem to be so common in other provinces. I wonder why?) We know that the theory/rumour is that you can get higher grades at summer school and thereby boost your admission average and chances of acceptance into the more competitive programs. We also hear concerns from other applicants and parents that this is an unfair advantage, because some are unable to attend summer school for various reasons. Currently we don’t penalize applicants taking summer school courses (unless it is to repeat a required course), but maybe we should? Since we like evidence-based decision-making, let’s use some data to see if summer school does give a significant advantage.
I’m going to use the Ontario grade data for applicants from a previous year, for the course ENG4U (Ontario grade 12 English), since that seems to be the most common summer school course choice. We divide the data into two groups, 1) those that took the course during a Fall or Winter semester (or both, for non-semestered schools); and 2) those that took it during a summer session.
For group 1 (regular school) we have: 1,999 grades, with mode 80%, mean 79.1%, and standard deviation 10.5.
For group 2 (summer school) we have: 654 grades, with mode 80%, mean 81.7%, and standard deviation 8.3.
Almost 25% or our applicants in Ontario that year did ENG4U in summer school! Looking at the statistics, the most frequent grade (mode) is the same for both groups (80%), and the summer school mean (average) grade is slightly (2.6%) higher. Of course, we need to run Student’s t-test to determine if this 2.6% difference is statistically significant, and it turns out that it is (at the 95% confidence level).
It seems that the theory is correct, you can get a higher mark in summer school, if only slightly higher. But that’s not the complete picture. We also should look at the distribution of grades to see what’s happening. So, below is a graph of the cumulative probability of grades for the two groups.
The grade distributions look fairly similar, especially at the upper end, but there might be some difference at the low end. I ran a two sample Kolmogorov-Smirnov significance test on the two distributions to quantify whether they are really different and it turns out that they are statistically different.
So, have we proven that taking English in summer school will give you a higher grade? No! We have to remember that correlation does not prove causation. How do we know that the summer school students aren’t self-selecting in some way, so that the two groups are not really comparable? The only way to determine this would be to take 1,000 students and randomly force one group to do summer school, while the other group is forced to do regular school English. This is not likely to happen.
Conclusions and Comments
So, it does appear that taking a summer school ENG4U course is correlated with a slight benefit for whatever reason, of 2.6% on average. This would boost a six course admission average by 0.43%, which is probably not going to make much difference for anyone except very borderline decisions.
However, there is a significant hidden downside to the summer school strategy. While spending time in class, applicants may not be getting as much of that work and/or volunteer experience that we like to see, resulting in a lower Admission Information Form (AIF) score. So, in fact, the summer school strategy may be counter-productive and actually reduce your chances. And as you can see in the graph above, it is possible to get relatively low grades in summer school too.
When asked, I rarely advocate doing summer school unless it’s necessary for some specific reasons. I would rather see our applicants get some “real world” work, volunteer, or other experiences that will look good on their AIF and their resume when applying for that first co-op employment experience in our engineering programs. Employers are not impressed by summer school.
So, back to the original question. Should we penalize applicants who take summer school courses? No, this (and other data we have reviewed) doesn’t seem to suggest there is a strong reason to implement any penalties. Any advantage is pretty minor, especially considering all the other variables that could be involved.

Thanks for the post!!
I’m currently retaking my advanced functions course in night school. I’m applying for computer science and I want my marks to be higher. How will this affect my chances?
And what if I had a legitimate reason for taking it again?
Sorry, I can’t really answer the first question. Computer science admissions are handled by the Faculty of Mathematics, not Engineering. They have their own procedures, and I’m not very familiar with them. Of course, you should always explain your circumstances on your Admission Information Form so the admission team can make the most appropriate decisions about course repeats.
Will my admissions be affected if I failed a course that isn’t a prerequisite or part of my top 6?
No effect. Unless it prevents you from graduating, of course.
Is night school frowned upon if it’s not a prerequisite course? How would be go about explaining it in the AIF?
Also, on the AIF would you prefer seeing a condensed list of major extracurriculars, or is it okay to mention a long list of them even if some are minor commitments?
Thank you!
Night school is not an issue for any course. Just briefly mention why you ended up taking a night school course. It just helps us understand your record.
In my opinion, a long list of minor activities can detract from your more major activities. I would focus on the ones that you found most meaningful or enjoyable.
Thank you for your advice!
Just two more quick questions. I made two small typos in my AIF. I’m quite nervous about this, and I really don’t want this to negatively impact my application. Is there anything I can do?
Also, is the AIF taken into consideration for the first round of acceptances?
A couple of minor typos shouldn’t have any effect. We’re more concerned with persistent grammar and spelling errors. There is no way to make revisions once it’s submitted anyways.
The AIF score is used in the first round if available.
I am repeating a course in private school since I can’t fit it in my day school schedule and night school is full and I know about the 3-5 penalty, but it won’t increase due to private school right?
The penalty is the same, no matter how the course is repeated (private, night, summer, day, online, …).
I got a 64% in my advanced functions class last semester so I’m taking it again during night school and I hope to improve my mark. How will this affect my admission?
We may have to apply the repeat course penalty (up to 5% off the overall average). You should explain your situation in your AIF, and make sure your night school submits a mid-term grade through OUAC before our admission round in early May (assuming you are in Ontario).
My first semester was really bad. Due to a lot of unfortunate incidents in my family, my grades weren’t good at all. Because of that I’ve had to change my first program choice. And now this semester I’m retaking a course in night school and will hopefully retake another during day school. The 1st course is a prequisite while the other is an elective. This means I’ll be taking my top 6 courses this semester.
I just wanted to know how this will affect my overall admission? In a good or bad way? How much does 2nd semester count towards getting admitted?
Sorry if it was too long.
Thank you
Sorry to hear that things didn’t go so well. This is one of those complicated cases that we consider on an individual basis, so it’s hard to say much here. Based on what you’re saying, it seems unlikely you will get an offer in the early round (March). But we make the majority of our decisions and offers in early May, so you will still definitely have a chance at that point, hopefully with the improved prerequisite mark. The 2nd semester grades are usually quite important for the May offers, because that’s when most people take another couple of the required courses.
Maybe it’s just my district where summer school was MUCH easier, but I know quite a few people in my school who took summer school and night school and their averages have been 7-8% higher than their previous year’s. Especially for people who’s not very proficient at English, a 75 -> 80 is worth a lot.
Personally I didn’t take summer school because I had projects planned over the summer and I didn’t want to take any “cheap” routes. Maybe summer school courses should also be weighted based on historical performance independently.
We continue to monitor this. Definitely work or other resume-building activities are better in my view, since it will help with co-op employment and experience in the “real world”.
After applying to Software Engineering at Waterloo, I’ve really appreciated the information and time you put in to this website. Also, for this article specifically, and as someone who’s taken AP Statistics, it’s nice how you have given us the data so we can draw our own conclusions, but also performed and talked about T-tests and confidence intervals. And of course the ever important “Correlation does not imply causation”. Thank you for maintaining this website, and hopefully I’ll see you next year at Waterloo! (albeit not in one of your classes)
Thanks. Yes, it’s always important to test our data so that we come up with rational and reasonably substantiated conclusions.
Is the AIF score used in the second round of offers, or is just for the first round?
Yes, certainly it’s used for all rounds.
Hey thank you for taking your time to answer these questions:
1.) I made a mistake on my AIF regarding the completion of a score and I need to change physics being completed at day school to night school. I understand that I can make an amendment and I was wondering if this will put me at a disadvantage when compared to a student that did not have any mistakes?
2.) If you repeat a course, is the 3-5% deducted from that specific course or is it deducted from the overall top 6 average?
3.) Considering how I’m taking night school, do I have to include the name of the school under the education history or post-secondary education part of the AIF?
Thank you for answering the questions !
1) no, minor mistakes or changes are unlikely to have any effect.
2) the 3-5% is deducted from the overall average, so it’s equivalent to up to 30% off the grade of one course (out of six).
3) It wouldn’t hurt to list the name. If you’re in Ontario, there is a small chance that the data will look like you are not taking physics at all, so listing it in the AIF can help protect you from outright rejection in May. (Explanation: when you drop a day school course and add night school, sometimes the mid-term grades don’t get submitted by the night school properly or in time. Then, to us it sometimes looks like you’re not taking a required course.)
I’m applying for the Architechture co-op program next year.. And was wondering if taking 4U English online this summer will affect my admission? I will also have a full time job this summer.. So I’m not sure if its a great idea.. Any thoughts?
I don’t know. Architecture has their own unique admission team and processes. Admission to Architecture is much more competitive than the rest of the Engineering programs, so it’s best if you contact them directly at archinfo@uwaterloo.ca and get accurate information.
I find that some other schools are able to do their Grade 11 and 12 courses semestered, which makes it easier for them which in turn could possibly lead into higher marks.At my highschool we don’t have any semestered subjects; we must to all courses in the same period of time. Do those looking over my admissions take this into consideration? Or is it something that will have to be overlooked?
I’ve analyzed semestered versus non-semestered school performance in the past. In our data it did not seem to have any significant effect, so we do not take it into consideration either way.
What is the data like for taking private school for ENG4U? I’m assuming that there’s a big discrepancy between day school and private, since most universities deduct private school grades.
We don’t have very good data on private schools. It’s quite complicated to analyze, so it often comes down to case by case analysis when making admission decisions.
Taking summer English course may also boost grades of other courses because it saves a lot of times in regular school studies
Possibly, although that hypothesis is difficult to test. We continue to look for statistical evidence that summer school courses are a factor of concern for admissions.