What is a scale? This is such a sign system for which a mapping is specified. The scale element is mapped to real objects. We can say that the measurement scale is a graduated ruler on which the values ​​of a quantity are applied (distance, temperature, pressure). The problem associated with ensuring high quality products is inextricably linked to the quality of measurements. If the latter does not meet the modern requirements of technological progress, there is no way to achieve the appropriate product quality. Further, it will be described in detail about why a measurement scale is needed. The types of measurement scales will also be discussed in detail in this article.
Product measurement and quality
As mentioned earlier, if you successfully resolve issues that are related to the accuracy of measuring the quality parameters of materials and other products, as well as maintaining modes in production technology, product quality will improve significantly. In simple words, quality control is a measurement of all parameters of technological processes. The results of their measurements are needed to control the process. The more accurate the results, the better the control.
The measurement state has the following basic properties:
- Reproducibility of measurement results.
- Accuracy.
- Convergence.
- The speed of receipt.
- Unity of measurements.
The reproducibility of the results is the proximity of the measurement results of the same value, which were obtained in different places, using different methods and means, at different times and by different people, but under the same conditions (humidity, pressure, temperature).
The convergence of the measurement results is when the results of measurements of the same value, which were repeated using the same means, by the same method, under the same conditions, with the same thoroughness, are close.
Any measurement is carried out using appropriate scales.
Scale of measurements. Types of measurement scales. Examples
It has already been said that the scale refers to a number of certain marks that are ordered. This series corresponds to the ratio of successive measured values.
What is a measurement scale ? This is a sequence of values that have different sizes and are of the same name. It must be accepted by agreement.
In practice, five types of scales are used:
- Scale order.
- Relationship Scale.
- Scale of names.
- Interval scale.
- The scale of absolute values.
Order scale
The places that quantities occupy on such a scale are called ranks. The scale itself is also called rank or non-metric. In it, all numbers are ordered by occupied places. The intervals between them cannot be accurately measured. This scale makes it possible not only to establish equality or inequality between the measured objects, but also to determine the nature of the inequality in the form of logical judgments such as “more and less”, “worse and better”.
Using the scale of order, you can measure indicators that are qualitative, but do not have strict quantitative measures. Such scales were widely used in psychology and pedagogy, as well as sociology.
Relationship scale
It differs from the interval scale by a strict determination of the position of the zero point. For this reason, it does not limit the mathematical apparatus used in processing the results.
What is a relationship scale? It measures the values ​​formed as the difference of numbers, which are measured on a scale of intervals. Thus, the calendar time is counted on the interval, and the time intervals on the scale of relations.
When using this type, the measurement of any quantity is an experimental determination of the ratio of this quantity to a similar quantity, which is taken as a unit. When measuring the length of an object, you can find out how many times it is longer than the length of another object, which is taken as a unit of length, for example, a meter ruler. If we apply only the scales of relations, then the measurement can be given a more particular, narrow definition: the measurement of any value is the empirical finding of its relationship to the corresponding unit.
Name Scale
This scale is also called nominal. She is the easiest. The numbers in it play the role of labels. They are needed in order to detect and distinguish the studied objects. The numbers that make up this scale are allowed to be swapped. There are no less-more relationships in it. For this reason, some people think that its use should not be taken for measurement. Using the scale of names, only a small number of mathematical operations can be performed. For example, you cannot subtract and add its numbers, but you can calculate how many times a certain number occurs.
Interval scale
This is the type in which the numbers are not just ranked, but are also separated by certain intervals. The zero point in this scale is arbitrarily selected. This sets her apart from the relationship scale. Examples include calendar time (in various calendars, the beginning of the calculus of years was established for some random reasons), the electric field potential, temperature, and the potential energy of the lifted load.
The results obtained by measuring on this scale can be processed by any mathematical method, except for the determination of relations. The data shown by the scale answer the question “how much less or more?”, But they do not make it possible to say in the affirmative that one of the values ​​of the studied quantity is several times smaller or larger than the other. For example, if the temperature in a room rises from 10 degrees to 20, it cannot be said that it is now twice as warm.
Absolute scale
Often the magnitude of something is measured directly. For example, they directly calculate the number of defects in products, the number of units of output, the number of students present at the lecture, how many years have lived, and so on. When making such measurements, the exact absolute quantitative values ​​of what is being measured are marked on the scale. The absolute scale has exactly the same properties as the ratio scale. The only difference is that the quantities indicated on the first are absolute, not relative.
The results obtained after measurement on this scale have the greatest reliability and information content. They are very sensitive to measurement inaccuracies.
Conclusion
Thus, it became clear what a measurement scale is and what it is used for. As it turned out, she was not alone. There are five of them, and each is used to measure certain quantities. If earlier it seemed that a scale should measure only physical quantities, then it turns out that in such sciences as psychology and sociology, there are also scales that measure numerical indicators. In fact, the psychological test is also such a scale.
The measured value is called a variable, and what the measurement is done is called a tool. As a result, data or results are obtained, which can be of different quality and relate to one of the scales. Each of them puts restrictions on the use of some mathematical operations.