Key Takeaways
- Random error is unpredictable and can occur in any direction, causing measurements to be scattered around the true value.
- Systematic error is consistent and occurs in the same direction, causing measurements to be consistently off from the true value.
- Random error can be reduced by taking multiple measurements, while systematic error can be reduced by identifying and correcting its cause.
What is Random Error?
The error in which the obtained value is random each time a set of readings are calculated is known as a random error. There are unknown variations and random values obtained. There is no repetition in the magnitude, and the nature of the error is inconsistent.
The value of the quantity being measured goes up or down drastically. This error is also observed when an instrument is read incorrectly, mostly in physics. A prominent example of random error is blood pressure measurements. Even if they are healthy, a person can observe an abnormal change in blood pressure or irregular fluctuations in it if a random error is observed.
Some of the subtypes of random error are reaction time errors and parallax errors. The parallax error is observed when the eyes are positioned incorrectly while reading a measuring scale. As the name suggests, a reaction time error is an error observed in an experiment where an incorrect result is observed due to the speed at which a person starts or stops the stopwatch. This type of random error is time sensitive and is observed mostly during experiments involving heating or cooling.
What is Systematic Error?
In mathematics, several types of errors can abrupt your flow of calculations and lead to an incorrect result. Systematic error is one of them. The error in which measuring a certain quantity gives a constant figure, or there is a change in that figure in regular intervals, is known as a systematic error. The obtained value is consistent even if you try to solve the problem more than once. A consistent value or pattern is observed.
There is a pattern or a system observed in this type of error. If you are calculating a set of readings and there are constant errors observed, then your calculation has a systematic error. The correction factor in this error is neglected.
The arrangement of a certain experiment can be quite different in reality than in theory. The main reason for this error is the usage of faulty apparatus during a certain experiment. It can be fixed by using valid apparatus or calibrating it. The accepted or predicted value is shifted from the value obtained when we observe this error. This error can be observed while blood pressure measurements.
Difference Between Random and Systematic Error
- An inconsistent pattern is observed in a random error, on the other hand, a consistent pattern is observed in a systematic error.
- The subsequent result is unpredictable in a random error, on the other hand, the succeeding result is comparatively more predictable in a systematic error.
- The value obtained in a random error does not get repeated, the value observed in a systematic error gets repeated.
- Random error is caused due to unpredictable variations, on the other hand, systematic error is caused due to usage of faulty apparatus.
- Eliminating random error is relatively difficult, on the other hand, eliminating systematic error is relatively easier.
Comparison Between Random and Systematic Error
Parameters Of Comparison | Random Error | Systematic Error |
---|---|---|
Meaning | The error in which the result obtained is drastically varied and keeps changing for every calculation is known as a random error. | The error in which the result obtained is consistent and keeps changing at regular intervals for every calculation is known as a systematic error. |
Nature | Inconsistent | Consistent |
Subtypes | Parallax error, reaction time error. | Observational error, instrumental error, and environmental error. |
Direction | Occurs bidirectionally | Occurs unidirectionally |
Elimination | Can be eliminated by repeating the readings. | Can be eliminated by changing the apparatus. |