One list and a weekly review: the two Getting Things Done habits worth keeping

David Allen's Getting Things Done (2001) has contexts, horizons of focus, tickler files, someday/maybe lists and a 43-folder filing system. People read it, set it all up on a Sunday, and quietly abandon it by the next month.

You don't need all of it. Two habits do most of the work, and they are the two with the clearest backing from research: capture everything in one list you trust, and review that list once a week.

Why unfinished things nag at you

E. J. Masicampo and Roy Baumeister ran a set of experiments, published in 2011 under the title "Consider it done!". They had people think about an important goal they hadn't finished, then gave them unrelated tasks. The unfinished goal leaked in: people had more intrusive thoughts about it while reading a passage, recognised words linked to it faster, and did worse on anagrams.

Then came the useful part. When people were asked to make a specific plan for the goal (what they would do, when and where), the interference went away, even though the goal itself was still not done. The plan was enough for the mind to stop rehearsing it.

Two limits are worth knowing. Planning didn't make people feel less anxious about the goal; it reduced the intrusions, not the worry. And the effect depended on the plan being earnest: a vague note doesn't count. Francis Heylighen and Clément Vidal, in a 2008 paper on the science behind GTD, make the related point that the mind leans on its surroundings as external memory, so a reliable list takes load off it.

Writing a task down with a next step tells your mind it can stop holding it.

Habit 1: one list you trust

"One list" doesn't mean one long column. It means one place where every commitment ends up: lists inside one app, not tasks spread across sticky notes, three apps, your email inbox and a notebook in the van. If something can live in two places, you'll check neither with confidence, and the mind goes back to holding it.

Capture fast. If adding a task takes more than a few seconds, you won't do it while standing in a kitchen or on a ladder. Use whatever is quickest: the phone, a shortcut, a voice note you move over later.
Write the next action, not the topic. "Mum's birthday" is a topic. "Order the cake from Lakshmi's by Thursday" is a next action. Masicampo and Baumeister's plans worked because they were specific.
Separate lists by where you are or who it's for, not by priority. Work, home, the site, the shop. Priorities change daily; places don't.

Habit 2: the weekly review

Allen calls the weekly review the "critical success factor" of the whole method. A list you never look at as a whole slowly fills with dead tasks, and once you stop trusting it, you're back to remembering things. His version has three stages: get clear, get current, get creative. Here is a lighter cut that takes about 30 minutes.

Get clear (10 minutes)

Empty the inboxes into the list: notes on your phone, scraps of paper, photos of whiteboards, emails that are really tasks. Don't do anything yet; just get each one onto the list as a next action or bin it.

Get current (15 minutes)

Look back at last week's calendar for anything that created a follow-up (a promise in a meeting, a delivery that came short).
Look at the next two weeks for anything that needs preparing now.
Go through every open task. For each one: is it still needed? Is the next step still right? If it has sat untouched for two weeks or more, shrink it, hand it to someone, give it a date, or delete it. (Tasks that keep sitting are usually tasks with a scary first step; see the two-minute start.)

Get creative (5 minutes)

Skim the someday list and ask: is one of these worth starting now? Write down any idea that came up. Then stop.

Pick a fixed slot: Friday afternoon works for many people because the week is still fresh. A weekly review that "happens when there's time" won't happen.

The small-team version

For a crew of three to ten people, the same two habits work at team level:
One shared list per job or site, where every request lands, with one owner per task. A task with two owners has none.
A 15-minute weekly look at the shared list, standing up if you like: what's done, what's stuck and who needs help, what's coming next week. Anything stuck for two weeks gets a smaller next step or a new owner.
Done stays visible until the review. Seeing what the team finished is part of why the meeting doesn't feel like a chore (more on why in Dopamine and the tick).

What the research does not show

There is no trial of the GTD method as a whole. The evidence covers parts of it: that specific plans reduce the pull of unfinished goals, and that external records take load off memory. The 30-minute timing above is a practical choice, not a tested dose. If your week is simple, 15 minutes may be plenty.

Sources

Masicampo, E. J. & Baumeister, R. F. (2011). Consider it done! Plan making can eliminate the cognitive effects of unfulfilled goals. Journal of Personality and Social Psychology 101(4), 667-683. doi:10.1037/a0024192. Psychology Today summary
Heylighen, F. & Vidal, C. (2008). Getting Things Done: the science behind stress-free productivity. Long Range Planning 41(6), 585-605. Preprint
Allen, D. Getting Things Done (2001, revised 2015). The weekly review: GTD podcast episode 43
Cover: clipart from Openclipart, released under CC0 (public domain).