Error & uncertainty: Quantitive Chemistry: Chemistry: GCSE (9:1)

• Uncertainty


  An estimate of how much a measured or calculated value differs from a true value
• Accuracy


  How close a measurement is to the true value of the quantity measured.

  
• Precision


  How close a series of measurements are to one another

  
• Human error


  Mistakes made by those carrying out the experiment
• Equipment error


  Defect in the functioning of the equipment.
• Procedural error


  Measurements can have error due to faulty method
• Random error


  Error that is due to chance
• Reliability


  The same person can repeat an experiment and get similar results
• Repeatability


  Different people repeat an experiment and get similar results
• Anomaly


  A result that is wildly different from other results
• Mean

  Average
• Reason results should be repeated

  So an average can be taken and anomolous results identified