The 8 types of measurement errors (with examples)

The types of measurement errors they can be random, systematic, disparaging or significant, among others. The measurement error is known as the difference between the value that has been obtained and the real value of the measured object..

Sometimes the error is so minimal that it is considered negligible. This means that the difference between the actual and measured values ​​is negligible and does not affect the result. In other cases the errors are significant, which means that the difference can affect the work being carried out..

In addition to negligible and significant errors, there are other types of measurement errors. Some are due to defects in the instruments used and others to mishandling of the instruments by the person carrying out the measurement..

The environmental conditions can also intervene in the measurement process causing the obtained data to be erroneous. Finally, the systematic error and the random error are found.

Main types of measurement errors

1- Random error

Random errors are those that occur when consecutive measurements are made of the same object or phenomenon, obtaining different values ​​in each case..

In the social sciences, random errors are represented by conditions that affect in a particular way a member of the sample that is being analyzed..

Example

The performance of a group of students in sports is being studied. There are hundreds of elements that affect each young person, such as the hours of sleep they have had, mood, physical condition, among others..

It should be noted that these conditions do not intervene in the performance of the group, but in that of a single individual, which adds interesting differences in the data obtained..

2- systematic error

Unlike random errors, systematic errors depend directly on the system that is being used to perform the measurement. For this reason, they are constant errors.

If uncalibrated instruments are used, they will give wrong measurements. The error will occur even if the measurement process is repeated.

In the social sciences, systematic error occurs when there is a condition that generally affects the performance of all individuals in the sample..

Example

A group of students must take a pop quiz on a content that has not been seen in depth in class.

The evaluation result is expected to be poor in each case, which represents a systematic error..

3- Contempt error

It is that error that, because it is minimal, does not constitute a problem for the measurements that are being carried out.

Example

If you are working in meters and the measurement varies by 1 millimeter, this error is considered not significant and the result is accepted as correct.

4- Significant error

The significant error is one that represents a problem for the work that is being performed. If the difference in measurements is very large, it will obviously be a significant error.

There are cases in which the difference is minimal but still significant.

Example

When preparing titrated solutions (those that require precise measurements of solute and solvent), an error in the measurement of the components will always be significant..

5- Error due to defects in the instrument used

Many of the mistakes made when making measurements can be attributed to the instruments used..

There are some instruments that need to be calibrated so that the measurements obtained are accurate..

The thermometers must be subjected to maintenance and calibration from time to time, so that there are no significant errors in the temperature measurements..

Example

Factory defects, warping, and other imperfections are some examples of what causes errors. In addition, instruments are subject to wear through use..

6- Error caused by the person taking the measurement

The human being is imperfect. Therefore, when an individual is in charge of taking measurements, there is a margin of probability that an error will be made.

Example

If measuring the volume of a liquid in a graduated cylinder, it is necessary for the operator to place his eyes at the level of the instrument to obtain an accurate measurement..

If the observer looks higher or lower than the mark, a measurement error will occur. This type of error is known as a parallelation error and is one of the most common.

If the observer has poor eyesight or is very careless, he may make mistakes when recording the data. For example, a 3 can be confused with an 8, resulting in a significant error..

7- Error due to environmental conditions

Temperatures, sound and other stimuli in the environment also affect measurements.

Example

Many materials are prone to varying in length with increasing and decreasing temperature..

If measurements based on sound intensity are being made, excessive noise can lead to errors.

In balances, accumulated dust can cause differences in measurements. In most cases, these will be negligible errors.

8- Error due to accident

A measurement can be altered by various uncontrollable unnatural causes that generate an accident.

Example

If during the making of a suit the power goes out due to an electrical failure, the tailor may fail to make a cut or spin.

References

1. Different Types of Measurement Errors and their Error Calculations. Retrieved on October 20, 2017, from edgefx.in
2. Errors in Measurement. Retrieved on October 20, 2017, from electrical4u.com
3. Measurement Error - Social Research Methods. Retrieved on October 20, 2017, from socialresearchmethods.net
4. Observational error. Retrieved on October 20, 2017, from wikipedia.org
5. Random vs. Systematic Error. Retrieved on October 20, 2017, from physics.umd.edu
6. Types of Error in Mechanical Measurement. Retrieved on October 20, 2017, from slideshare.net
7. Types od Measurement Error. Retrieved on October 20, 2017, from geographer-miller.com
8. What is Measurement Error? Retrieved on October 20, 2017, from circuitglobe.com