Recursion without mystery.
Base case, recursive step, and when to trust the smaller problem.
Articles
11 pieces · RSSWriting on computing, education, and evidence — for people who teach, learn, and decide.
Algorithms
Bellman–Ford, explained clearly.
Finding shortest paths when edge weights can be negative.
Computing education
Computer science has two parents.
Why studying the subject means learning both what can be computed and how to make computation work.
Debugging as a teachable habit.
Why errors are information, not embarrassment.
Teaching computing beyond syntax.
Why correct programs are not always enough.
Education and AI
Fluent answers are not understanding.
When correct-looking work teaches nothing.
LLM fluency is not reasoning.
Why fluent language from a model is weak evidence of understanding.
Measure before you optimise.
Why the first question in analytics is what counts as evidence.
Productive struggle in learning.
Why some difficulty earns learning — and some shortcuts remove it.
Other writing
Compact controls in Edmetry Focus
Reviewing one settings group before adding more local styling.
When the scores are the same
Similar results can hide very different demands on the people who use them.