有幾個詞我常分辨不了，可否為我解答？

1. Accuracy is how close a measured value is to the actual (true) value.
e.g. in length measurement, if the actual length is 2 cm, say. Then a measured result of 2.01 cm is more accurate than another result of 2.1 cm
Precision is how close the measured values are to each other.
e.g. in the above measurement of length, a measured result of 2.001 cm is more precise a measured result of 2.01 cm
You can look at the follwoing web-page for more details:
http://www.mathsisfun.com/accuracy-precision.html
2. Compare with systematic error, random error and mistake.Gross errors are undetected mistakes that cause a measurement to be very much farther from the mean measurement than other measurements.
An random error, by definition, is an error that results from unpredictable variations from one or more influenced quantities.
Examples of random error are measurements of the length of a room (you would expect a bit different result for repeated mesurements), or measurement of time going to school.
Systematic error is an error that is not determined by chance but is introduced by an inaccuracy in the system. Systematic errors are predictable and expected.
An example of a system error is a "zero error" on a measuring device - for instance, scales which report a weight even when there is nothing on them.