The 2+1 Rule: the Importance of Diversity in Reference Letters

Today I got an email from a reader asking me for some advice on which referees he should ask to write his three letters for medical school admissions. If you haven’t read my first article on reference letters, I urge you to do so before reading this one. If you’re too lazy, the cliff notes of that article are that you should pick referees who know you very well and who you know genuinely want to support you in your quest to become a doctor. Simply put, unless your referee has known you for a long time, he will have nothing of substance to say about you. And unless your referee really wants you to become a doctor, then he has no reason to producing something with substance.
Of course, the question that remains is: “but what if my three strongest references are too similar”?
Why Diversity is Good
We have established that the strength of the letter is more important than who wrote it. It’s easy to see that what is written is significantly more important than who it is written by. For example, a one page letter written by your research supervisor is probably going to be better than one paragraph written by the dean of your faculty. However, one clear exception would be if your strongest possible letters would end up being too similar in content.
Reference letters can become redundant if they are focused on the same thing, and worse, they can leave out important information. For instance, if your three referees were all professors / researchers you worked with, chances are a lot of the same traits will be mentioned (e.g. intelligence, work ethic, problem solving, etc.). While these are most definitely traits necessary for a good physician and traits you want highlighted by your referees, you want to ensure that your reference letters hit on as many relevant traits as possible. You also want one or more of your referees to evaluate your abilities in compassion, empathy, etc. – traits less likely to be seen in a research environment, but commonly utilized in various community/volunteer experiences (which many of you are bound to have).
One quick way to think about this (at least for Ontario medical school applicants) is to check the OMSAS reference form and see what traits the referee is supposed to rate you on: intellectual capacity, initiative, leadership capabilities, maturity, cooperation, integrity, problem solving, fluency in spoken/written English, ability to communicate, ability to relate to others, ability for self-directed learning, and critical thinking ability.
Knowing that you are being rated on these qualities, you want to select referees whose relationship/experience with you is diverse enough to achieve high ratings across all of these traits, even if those high ratings don’t necessarily come from the same referee. The point is to prove you are strong in all of these categories in some way or another, and it may be hard to do that if all of your referees are commenting on the same few traits. Two referees saying you are smart and one saying you are compassionate is way better than three referees saying you are just smart (That being said, it would be even better if all three said you were both smart and compassionate, so let’s aim for that when picking our referees!).
Long story short, physicians are multi-dimensional and therefore, you want your reference letters to reflect the same about you. It can be hard to do this unless your referees themselves come from diverse backgrounds and have different experiences with you.
So how should we go about obtaining diversity? The 2+1 Rule
To make it easier, let’s start by simply dividing up all possible referees into two groups: academic vs. non-academic. Academics would be individuals like course professors, research supervisors, etc – basically anyone who has seen you in an academic setting and can comment on you as a scholar and student. Non-academics would be individuals like volunteer supervisors, club facilitators, team coaches, etc. – anyone who has seen you in a non-academic, and more extra-curricular capacity.
We’ve established that if possible, we don’t want all three referees as academics, and nor do we want all three as non-academics. In that case, the only satisfactory solution is what I will now name as the 2+1 Rule of reference letters: you should aim for at least one academic and one non-academic reference letter, with the third letter being anything that you want (leading to 2 academic/1 non-academic or 2 non-academic/1 academic, and hence, the 2+1 Rule).
Personally, I had one academic (research supervisor) and two non-academic (two volunteer/community experience supervisors). While my research supervisor could most definitely account for my intellectual capacity, problem solving and critical thinking ability, there’s no way he would have been able to comment on my cooperation and ability to relate to others to the extent that my choir director was able to, and vice versa. But taken together, all three reference letters were able to create a complete picture of me, as a candidate with all of the traits sought for.
In the story I referenced at the beginning of the article, the student who emailed me listed all of his potential referees, and it was clear that he felt his strongest three letters would come from three academics. But once I saw that he had a volunteer supervisor who he had worked a fair bit of time with and whose strength of letter he predicted would be almost as good as the other three, in my mind, it was an easy decision to pick the two best academic letters and include the volunteer supervisor as the third, even though the three academic letters would each have been better in a vacuum. The key point here was deciding on which three letters work together best in combination, and that is best achieved using the 2+1 Rule as a foundation.
What if I can only find 3 strong references of the same type?
One caveat to the 2+1 rule is if you feel you lack a strong reference in either the academic or non-academic field – if this is you, it might be important to ask to what degree you are exploring both your academic and non-academic aspects of your life, and if there is something you should explore further. However, sometimes you may simply have to go with three academic or three non-academic referees – and that’s fine. There are most definitely medical students who had three academic or three non-academic referees.
That being said, I would ask your referees to comment on as many traits as possible, beyond what they normally would (e.g. if you have three academic references, ask them to comment on more than the usual academic-related traits). Bring up specific experiences of yours that you think they should keep in mind. For example, if you have three academic references, ask them if they know of your experiences beyond the academic setting. Have any of them see you do things in the academic setting that would demonstrate compassion or empathy, for instance?
Who writes your letter isn’t as important as the letters presenting you as well-rounded, complete candidate. As long as they can do that, I think it’s fine if your referees are all academic (or all non-academic).
To sum up, you want to pick referees who have known you the longest, who genuinely want to help you get into medical school, and who as a group, can positively comment on all of your different qualities.
Related Posts:
- If I ran a medical school, this is how I would do admissions
- So I didn’t get into medical school… what now?
- McMaster CASPer Resources and Thoughts
- How I got a T on the MCAT Writing Sample
- Why GPA Should Matter and Learning the Way You Learn Best
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Comments
Hi Josh,
Thanks for the awesome advice! I just discovered this blog via PreMed101 and it is a GODSEND.
I’m currently a full-time graduate student hoping to apply this Fall… and am stuck with the question of who my +1 should be. I have many, many awesome referees for academic letters, but haven’t done much volunteering since my early undergrad years. Any advice?
Thanks!
Hi Joshua,
I have been working at a lab, but as my supervisor is a busy physician, I have had A LOT of interactions with research coordinator who supervised my research progresses more so than the physician/PI.
Would it be better to have the physician to write my letter as he is actually the PI, or would it be better to ask the coordinator to write one who knows me and my work better although he is not a “doctor”?
That being said, would not having a doctor/physician as a referee looked down upon, especially at UofT (logistically, this is my first choice).
Thanks for your input in advance!
Hi,
Awesome article!
I also have a question. Last year I had 2 academic referees and one volunteer supervisor. Out of the academic referees, one was a science prof and the other was a prof for another class (more about health issues etc not really intense science).
However, this year, my academic referee (science prof) is out of town right now and he won’t be back until after the deadlines. Do you think it’s ok if my only academic is my other prof?
Thanks!
Thanks for the reply Joshua. My other referee…knows me really well personally as well, so I know his reference will be strong. I’m just a little bit worried because I would have liked to have a reference from someone who knows my science background as well. But we’ll see what happens.
Thanks again.

MedHopeful @ Premed101
The “2+1″ rule is interesting because that’s what I did myself (unknowingly)!
My three reference letters were:
1) my research supervisor of 3 summers
2) a professor who was my interviewer for a university research scholarship (that I received) and also taught a course that I did really well in
3) a community organization volunteer coordinator that sat on the executive of an university club that I was part of for two years, and eventually became campus coordinator of