[theforce007]

Anyone know why the answer to the following statement is both?

We are unable to determine the "true" value of an analysis- true or false or both?

[Arkcon]

It really does depend on the circumstances.  So I suppose in a pure T/F exam, the answer is both.  But, if you've done the experiment, you may be called on to justify your answer.  So you'll want to take into account all the information you have.

[fledarmus]

That's sort of an odd way of asking the question. I presume this is a way of contrasting accuracy and precision, and by "value" they mean a numerical value for a measurement?

There are ways to remove the lack of precision from most measurements, and better techniques can lead to smaller errors between measurements and more decimal places of precision. There is no real way of knowing the accuracy of a measurement, however, except by comparing it with some other way of measuring the same property. It is always possible that there is a systematic error in your form of measurement that affects every measurement equally, and you can measure the wrong value extremely precisely. Even when comparing your measurement with another way of measuring the same property, it is possible that the other method also has systematic biases, and there are reams of journal discussions about which method of measuring a property leads to a more accurate result. Precision is rarely in doubt - a few measurements and some statistics pretty much settles that point.