# what is the difference between reliability and precision?

I found this on the internet:
Precision is how 'detailed' your data is. For instance, 4.576 would be more precise than 4.5. Precision, however, dos not necassarily make your data more accurate.

Reliability comes from repeating your experiments to ensure that you get the same/ similar data each time. You may only do an experiment once and get a very accurate answer, however, this would not be reliable until you repeated your experiment a number of times to arrive at the same answer.

However,in my biology book it says

Precision refers to the closeness of repeated measurements to each other.

The second definition of precision is quiet similar to that of reliability,so what is the difference bewteen them? Which definition for precision is right? Can anyone help me,please.
These are the definitions of reliability and precision that I have. Precision is how the data you've collected in an experiment matches up with each other, you know how you do an experiment more than once? It's how well they match. This is like an official definition; Precision refers to how well experimental data and values agree with each other in multiple tests.

Reliability is like whether the experiment has been repeated or not. Always put repetition if if asks for something like "How could you improve the reliability of this experiment?" Also depending on the experiment it reliability can be improved through a large sample size.

Hope this helps.
Reliability is whether the experiment CAN be repeated or not. Make sure there are no systematic errors. This is coming from a physicist so sorry if I'm wrong :P

The guy above got the precision bit right
Original post by SusieDDDDDD
I found this on the internet:
Precision is how 'detailed' your data is. For instance, 4.576 would be more precise than 4.5. Precision, however, dos not necassarily make your data more accurate.

Reliability comes from repeating your experiments to ensure that you get the same/ similar data each time. You may only do an experiment once and get a very accurate answer, however, this would not be reliable until you repeated your experiment a number of times to arrive at the same answer.

However,in my biology book it says

Precision refers to the closeness of repeated measurements to each other.

The second definition of precision is quiet similar to that of reliability,so what is the difference bewteen them? Which definition for precision is right? Can anyone help me,please.

I find this useful:

Hope it helps
Original post by SusieDDDDDD
I found this on the internet:
Precision is how 'detailed' your data is. For instance, 4.576 would be more precise than 4.5. Precision, however, dos not necassarily make your data more accurate.
Reliability comes from repeating your experiments to ensure that you get the same/ similar data each time. You may only do an experiment once and get a very accurate answer, however, this would not be reliable until you repeated your experiment a number of times to arrive at the same answer.
However,in my biology book it says
Precision refers to the closeness of repeated measurements to each other.
The second definition of precision is quiet similar to that of reliability,so what is the difference bewteen them? Which definition for precision is right? Can anyone help me,please.

Both definitions of precision are correct.