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Meaning of uncertainty

  1. Nov 15, 2011 #1
    hi this is my first physical post , i hope i find the right help
    i just want to know the meaning of uncertainty and the difference between unceratinty and errors any explaination would help
  2. jcsd
  3. Nov 16, 2011 #2


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    Staff: Mentor

    Re: experiments

    I suggest that you go to http://ask.com" [Broken] and type in a suitable query, such as What is the difference between uncertainly and error in measurement?

    You will find that ask.com is a very good site for posing such questions.
    Last edited by a moderator: May 5, 2017
  4. Nov 16, 2011 #3
    Re: experiments

    thank you
  5. Nov 18, 2011 #4

    Claude Bile

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    Science Advisor

    Re: experiments

    The error is the difference between a measured value and the known, "true" number, while the uncertainty is the statistical standard deviation of repeated measurements. Note that the calculation of uncertainties does not require prior knowledge of a "true" value.

  6. Nov 18, 2011 #5

    Andy Resnick

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    Education Advisor

    Re: experiments

    When analyzing an experiment, it's sometimes useful to separately consider 'accuracy' and 'precision'. Accuracy is how well the (average) measured value agrees with the 'true' value, which may be determined by use of a standard, and your term 'error' may correspond to 'accuracy'. Precision refers to the spread of measured values, which may refer to your term 'uncertainty'. It's possible to have very precise and inaccurate measurements, poor precision and high accuracy, or some other combination. Loss of accuracy is sometimes called 'systematic error', while lack of precision is sometimes called 'random error'.


    Also, there is uncertainty in the underlying object itself if stochastic processes are present. One way to think about this is that we have imprecise information about the object (or process).
  7. Nov 19, 2011 #6
    Re: experiments

    mr andy resnick , thank very much , that was exactly but is it okay to say error and uncertainty??? just curious
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