Tracking progress works — and writing it down works better

This is the study that gives a tracker a reason to exist. Across 138 experiments, monitoring your progress improved the odds of reaching the goal — and the effect was larger when the progress was written down rather than merely noticed.

What a meta-analysis actually is

A single study is a noisy measurement. Run the same experiment twice and you get two different numbers. A meta-analysis pools many independent experiments and asks what remains once the noise cancels out.

Harkin and colleagues collected 138 experiments in which people were randomly assigned either to monitor their progress toward a goal or not — across health, work, education and personal behaviour — covering 19,951 participants in total.

The result

Monitoring progress reliably increased goal attainment, with a pooled effect of d = 0.40. In behavioural research that is a moderate effect, and moderate effects that replicate across 138 experiments are worth considerably more than large effects that appear once.

The more useful finding is in the moderators. The effect was larger when progress was physically recorded, and larger again when it was reported to somebody else.

What that means

Recording is not administrative overhead sitting on top of the real work. It is part of the mechanism. Noticing that you did something and writing down that you did it are not the same act, and the data can tell them apart.

It also sets a boundary. d = 0.40 is a real effect, not a miracle. A tracker will not carry you on its own. Anyone selling you one on the promise that it will is overselling the evidence — this page included.