Hi, I'm Geoff

I love to teach, and I love to code.
I teach students to code.
And I write code that helps them learn.

My goal is to teach computer science to as many students as possible. I do this by creating interactive learning environments that scale. More about me...


I post essays here on teaching, technology, and the overlap between the two. I try to keep my essays on teaching accessible to teachers who don't program, and my essays on technology interesting to programmers who don't teach.

Here are my latest four essays. For the complete set, click here.

2021-11-26 : Windows Line Ending

In today's advertures in maintaining your own CS1 infrastructure, how Windows line endings and a persistent student combined to bring down our entire homework grading backend.

2021-11-21 : CS1 in Kotlin

In Fall 2021 we began offering Kotlin as a language option in my CS1 course. Kotlin has proven to be a great choice, and represents a substantial improvement over other popular options like Python and Java.

2021-08-13 : Grade Uncertainty

Grade uncertainty represents the amount of uncertainty students have about how they are doing in a course. Reducing grade uncertainty has proven positive in my courses, even if it has had some interesting side effects.

2021-07-30 : Poorly Structured

Why are college courses structured so differently from classes in high-school? And does introducing more structure help our students learn better?

For more essays, click here.