2.  Systematic errors are errors associated with a flaw in the equipment or in the design of the experiment. Systematic errors cannot be estimated by repeating the experiment with the same equipment. Consider the example of measuring an oscillation period with a stopwatch. Suppose that the stopwatch is running slow. This will lead to underestimation of all our time results. Systematic errors, unlike random errors, shift the results always in one direction.

3.  Errors that can be reliably estimated by repeating measurements are called random. Some of measurements will be above the mean, while some of them below. That's why we call this kind of error random. Our error estimate is obtained from the random distribution of our measurements around the mean value.

4.  Systematic errors are much harder to estimate than random errors. After all, how could we have known beforehand that our stopwatch was unreliable? In order to identify systematic errors, we should understand the nature of the experiment and the instruments involved. Sometimes you will encounter significant systematic errors in your experiments. If you suspect that your measurements are biased, you should try to identify the possible sources of systematic error

5.  http://ed.ted.com/lessons/what-s-the-difference-between-accuracy-and-precision-matt-anticole

6.  Any measuring apparatus used has an associated uncertainty.  As a general rule, the uncertainty is often taken to be half a division on either side of the smallest unit on the scale you are using. However, the accuracy of measurements does also depend on the quality of the apparatus used, such as a balance, thermometer, caliper or glassware.  For example A 30cm ruler - divisions of 1 mm therefore an uncertainty of half a division or 0.5 mm either side so a total uncertainty of 1mm A caliper has an accuracy of 0.01 mm when used by a skilled operator

7.  Voltmeter A voltmeter has an uncertainty of 0.01V as what you see on the display is 2 decimal places  Time Measurement A stopwatch measures time with a resolution of 0.01s, however the operator reaction time is significantly longer, increasing the total uncertainty in the measurement. An acceptable reaction time is 0.3s.

15.  Worksheet - Uncertainties