[cuongt]

can sum 1 explain to me what the meaning of systematic and random errors for me plz.


 

[billnotgatez]

http://en.wikipedia.org/wiki/Error

[cuongt]

didnt realli help me lol cause i need to explain in my prac if there were any random or systematical errors and i dun know what they mean

[xiankai]

random errors are things that fluctuate from time to time, like human errors (our response time is slow), direction of wind (speed measured may not be accurate), and stuff like these.

systematic errors are those that do not fluctuate, and thus can be rectified. examples include a wrong scale of the ruler (1 cm on the ruler is longer than the standard 1 cm), zero error on the vernier caliper (calipers are pushed too far too the right or left), etc.

[jcais]

How I remember it is that a random error is like throwing darts all over the dartboard.

Systematic error is like throwing the darts all in one corner or in one place of the dartboard never hitting the bullseye.

no error is hitting the bullseye.

[mike]

Random error: These are fluctuations in a measurement (can be either positive or negative) due to the limitations of the thing you are using to take the measurement (and the person making the measurement). This basically means that an experimenter (yourself or any of us) do not take the same measurement in exactly the same way each time we make it, so there will be slight variations from measurement to measurement. Random errors can be reduced by taking a large number of measurements.

Systematic errors: These errors are exactly the same each time (they are in the same direction, ie either negative or positive) and are due to a "problem" in the whole experiment. Each time you take a reading it is off in the same direction by the same amount no matter how many times you make the measurement.

Some examples:

Random error:  If you were to use an electronic balance to measure the mass of something and you did it three times you may get values of 45.56g, 45.58g, 45.54g. These are random errors and will decrease the more times you take the measurement.

Systematic error:  Using the same example but this time your electronic balance has been tared incorrectly (for example it is tared 0.05g too high) so every measurement you make will be out by 0.05g, everytime, no matter how many measurements you make.

Note that these types of errors are associated with making measurements and are not the same as mistakes made by the experimentor. So forgetting to tare your balance for one of your measurements is not an error of measurement.

Maybe if you tell us some more information about your experiment we could be more specific.