baseline

Everyday

1. A starting measurement that you use to compare later results with. tree →
2. In tennis and some other sports, the line at the back of each end of the court. tree →
3. A basic line or level, such as the lowest acceptable standard. tree →

In the lessons

In science experiments, the baseline is what you measure before you change anything, so you can see how much changed. In school tests, a «baseline test» shows what a pupil knows at the start of the year. In tennis lessons, players serve from behind the baseline.

Examples

• We measured the plant's height as a baseline before adding fertiliser. tree →
• The baseline test showed what we knew in September. tree →
• My resting heart rate is my baseline before running. tree →
• She hit the ball right on the baseline. tree →
• Stand behind the baseline to serve. tree →
• Compared with the baseline, the temperature rose by 5 degrees. tree →
• A baseline helps you see if your spelling has improved. tree →

Note

Countable: a baseline, baselines; sometimes spelt «base line». In maths and science problems, the change = new value − baseline: if the baseline is 20 and the new value is 26, the increase is 6. Do not confuse with «bassline» (the low notes in music).