Decide When and Where

What the research found

“Tomorrow I’ll work on the proposal” is a goal. “Tomorrow at 9, when I sit down at my desk, I’ll write three headings for the proposal” is what psychologists call an implementation intention. It takes the form “if situation X arises, then I will do Y,” linking a specific cue to a specific action.

Gollwitzer and Sheeran (2006) combined 94 tests of implementation intentions. Compared with holding a goal alone, forming an implementation intention made people more likely to reach their goals, with an average effect size of d = 0.65.

Later, Sheeran, Listrom and Gollwitzer (2025) carried out a much larger meta-analysis of 642 tests. The main findings:

• Implementation intentions helped with cognitive, emotional and behavioural outcomes (d from 0.27 to 0.66).
• Plans in an “if–then” format had larger effects (d = 0.43) than plans written as a simple schedule (d = 0.29). Effects were also larger when people were highly motivated and when they rehearsed the plan.
• Specifying only a time gave d = 0.25; specifying both a time and a place gave d = 0.46. Adding more detail about how or for how long actually made the effect smaller (d = 0.24).

How to read it

Both studies combine experiments, so we can say that forming implementation intentions led to better goal attainment. The size of the effect needs care, though.

Across the 642 tests, the overall average was d = 0.36. The authors also found substantial publication bias: small studies with positive results were over-represented. One correction method (trim-and-fill) gave d = 0.35, and a stricter one (robust Bayesian meta-analysis) gave d = 0.15, which counts as small by conventional standards. The authors themselves conclude that the effect is robust but small, and varies a lot between studies.

So the accurate picture is that an implementation intention is a tool that makes following through somewhat easier. Most of the studies were run in the UK, Germany, the US and a few other countries, and none of them looked directly at job performance or income.

A small step for today

Here is how the findings translate into the app’s evening habit.

1. Pick just one important task. Rather than making many plans, focus on one.
2. Decide both the time and the place. “Tomorrow at 10, right after I leave the meeting room,” or “in the morning, on the station platform.” Time plus place had a bigger effect than time alone.
3. Don’t over-specify. Keep the action short and single; leave out step-by-step instructions and durations.
4. Rehearse it once. Picture the moment and imagine yourself starting.

If tomorrow’s cue doesn’t happen (the meeting is cancelled, the train is late), don’t treat the day as lost. Pick a new time and place on the spot. The plan is a starting signal, not a test you pass or fail.

When you’ve done it, tick “Set when and where to do tomorrow’s key task.” If you plan in the morning instead, pair it with “Planned the day in the morning.” The effect may be small, but it is a tool you can use every day.

Sources

• [E3] Gollwitzer & Sheeran (2006) Implementation intentions and goal achievement: A meta-analysis of effects and processes. Advances in Experimental Social Psychology.
• [X-sheeran-2025] Sheeran, Listrom & Gollwitzer (2025) The when and how of planning: Meta-analysis of the scope and components of implementation intentions in 642 tests. European Review of Social Psychology.