Writing a good PhD SoP can be a daunting task. Fortunately, there are plenty of good posts out there about how to approach the writing process and what a good SoP looks like (in particular, I followed the structure laid out by this post by Tim Dettmers and this post by my undergrad advisor Stefanie Tellex). When I was writing my own SoP, what I probably found most-helpful on top of the above-linked posts was reading SoP’s by students in related areas who had been successful with the PhD application process (in particular this one from Nelson Liu). Given how much I benefitted from these, I figured I’d try to give back and contribute to the genre. Below, you can read the SoP that helped me get admitted to MIT:
If I had to give two pieces of advice to anyone writing an SoP, it’d be these: make it both research-dense and skimmable. I think it’s useful to think of an SoP as an application for a research job instead of a college essay: it should focus almost exclusively on things directly relevant to your ability to do good research (namely, your past experience and your interest and ideas going forward). Relentlessly cut-out any fluff. This is especially important because people on PhD admissions committees often skim SoP’s quickly (often because of the sheer volume of applications received). For this reason, it’s also useful to optimize your essay for skimming: do things like having the first 1 or 2 sentences of each paragraph setup what the paragraph will be about, or italicizing/bolding important words/sentences, etc. You shouldn’t take this too far and make your writing too terse or lazy though; remember that eventually, Professors will carefully read your entire SoP!
Good luck with writing and the overall grad school application process!