Before a speaking test, you sometimes get one minute to think. Does it help? In 1998, a researcher gave learners of German no time, one minute, five minutes or ten minutes before they spoke. With more time, they spoke more smoothly.

Their grammar got better after just one minute, but more time did not make it better. Another study found that 30 seconds was too short. But in a test study with 90 people, planning did not change their scores.

In Part 2 of the IELTS speaking test, you get one minute and a pencil before you talk. Researchers have studied this kind of planning time for many years. A 2009 review by Rod Ellis found that planning helps fluency, so learners pause less.

The results for accuracy and complexity were mixed. Two studies looked closely at the length of planning time. In one, learners of German made their speech more accurate after one minute, and extra time did not improve accuracy further.

In the other, one minute was the point where accuracy clearly improved. Thirty seconds was too short, and five minutes worked less well. But when 90 people did IELTS tasks with no planning, one minute or two minutes, their scores stayed about the same.

Thirty-one learners of German were split into four groups in a 1998 experiment. One group started talking at once, and the others had one, five or ten minutes to plan. Fluency rose steadily with more time. Accuracy went up after a single minute and then stayed flat, and complexity only improved with ten minutes.

A later study of test-style tasks compared six conditions, from no planning up to five minutes. Accuracy improved the most, with one minute as the threshold. Thirty seconds was not enough, and five minutes brought smaller gains.

A 2009 review of the field found that planning helps fluency, while its effects on accuracy and complexity depend on the task and the learner. Test scores are another matter. Ninety intermediate and advanced IELTS candidates did three tasks with no planning, one minute or two minutes.

Neither the raters' scores nor a close analysis of their speech showed a significant difference. Lab and test studies differ in tasks, learners and scoring, so a gain in one setting may not carry over to the other. Even so, the authors argued that offering one minute is worth considering, because it could make the test fairer for candidates.