Standard deviation and standard error

[i_love_science]

The mean of some data was 21.2°C, the standard deviation was 2, and the standard error was 0.8.

My textbook says that using one standard deviation, we would report the temperature of the substance as 21.2 ± 2°C, while using the standard error, the temperature would be reported as 21.2 ± 0.8°C.

If I did not know whether the temperature was reported using standard deviation or standard error, how would I determine that from the given value itself?

Thanks.

 

[mjc123]

You can't. Without any indication, it could be SD or SE, or something else, e.g. 95% confidence interval (±2 SE). You should always make it clear what your uncertainty figure refers to.