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Quality of measuring information  Просмотрен 325

Reliability of measuring information at measurements on an order scale. Reliability of measuring information at measurements on the graduated scales.

In a serial scale of number are used not only for distinction of objects, but also for order establishment between objects. The elementary example are estimates of knowledge of pupils. It is symbolical that at high school estimates 2, 3, 4, 5 are applied, and at the higher school exactly the same sense is expressed verbally - unsatisfactory, satisfactorily, well, excellent. It emphasizes "non-numerical" character of estimates of knowledge of pupils. In a serial scale all strictly increasing transformations are admissible.

Establishment such as a scale, i.e. tasks of group of admissible transformations of a scale of measurement - business of experts of the corresponding applied area. So, an assessment of appeal of professions we in the monograph [2], representing itself as sociologists, considered measured in a serial scale. However certain sociologists disagreed with us, believing that graduates of schools use a scale with narrower group of admissible transformations, for example, an interval scale. Obviously, this problem belongs not to mathematics, and to sciences about the person. For its decision rather labor-consuming experiment can be put. While it is not put, it is expedient to accept a serial scale as it guarantees against possible mistakes.

Estimates of experts as it was already noted, often it is necessary to consider measured in a serial scale. A typical example are problems of ranging and classification of the industrial facilities which are Theme to ecological insurance.

Why it is natural to express opinions of experts in a serial scale? As showed numerous experiments, the person more correctly (and with smaller difficulties) answers questions qualitative, for example, comparative, character, than quantitative. So, it is easier to it to tell, what of two weights is heavier, than to specify their approximate weight in grams.

In various areas of human activity many other types of serial scales are applied. So, for example, in mineralogy the scale Moosa on which minerals are classified according to criterion of hardness is used.

Namely: talc has a point 1, plaster - 2, calcium - 3, fluorite - 4, apatite - 5, ортоклаз - 6, quartz - 7, topaz - 8, corundum - 9, diamond - 10. The mineral with big number is firmer, than a mineral with smaller number, by pressing scratches it.

Serial scales in geography are - бофортова a scale of winds ("calm", "light breeze", "a moderate wind" etc.), a scale of force of earthquakes. Obviously, it is impossible to argue that earthquake in 2 points (the lamp shook under a ceiling - such happens and in Moscow) exactly in 5 times is weaker, than earthquake in 10 points (final fracture of all on an earth surface).

In medicine serial scales are - a scale of stages of a hypertensive illness (according to Myasnikov), a scale of degrees of warm insufficiency (on Strazhesko-Vasilenko-Langu), a scale of degree of expressiveness of coronary insufficiency (according to Fogelson), etc. All these scales are constructed according to the scheme: the disease is not revealed; first stage of a disease; second stage; third stage … Sometimes allocate stages 1а, 1б, etc. Each stage has the medical characteristic peculiar only to it. At the description of groups of disability of number are used in an opposite order: the heaviest - the first group of disability, then - the second, the easiest - the third.

Numbers of houses are also measured in a serial scale - they show, in what order the street house stand along. Numbers of volumes in collected works of the writer or number of affairs in archive of the enterprise are usually connected with chronological order of their creation.

At an assessment of quality of production and services, in a so-called kvalimetriya (a literal translation: quality measurement) serial scales are popular. Namely, the unit of production is estimated as suitable or not the suitable. In more careful analysis the scale with three gradation is used: there are major defects - there are only insignificant defects - there are no defects. Sometimes apply four gradation: there are critical defects (doing impossible use) - there are major defects - there are only insignificant defects - there are no defects. The similar sense has production rating - the premium, the first grade, the second grade, …

At an assessment of ecological influences the first, most generalized assessment - usually serial, for example: environment is stable - environment is oppressed (degrades). Similarly in an ekologo-medical scale: there is no expressed impact on human health - negative impact on health is noted.

The serial scale is used and in many other areas. In эконометрике it first of all various methods of expert estimates. (see the material devoted to them regarding 3).

All scales of measurement divide into two groups - scales of qualitative signs and a scale of quantitative signs.

Serial scale and scale of names - the main scales of qualitative signs. Therefore in many concrete areas results of the qualitative analysis can be considered as measurement on these scales.

 

Control questions:

1. Quality of measurements on an order scale

 

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