# Scales for measurement of variables

Measurement scales

Continued from: Operational Definition

To measure is to assess, quantify, analyze or appraise. It is to discover the extent, dimensions, capacity and quantity of any physical object.

Business research deals with physical objects as well as ideas. “How sound is an idea” is parallel to assessing “how well you like a song, a painting or personality of your boss”. While physical objects are measured directly, ideas or concepts are measured with the help of an operational definition. Obviously, salesmanship cannot be measured directly but it is easy to set a benchmark for a good salesman as one having sold 200 cars per year without any complaint.

Four scales are used to measure any object or to quantify any concept or idea or properties. These are discussed as follows:

## NOMINAL SCALE

It is just a label having no intrinsic value or quality. It cannot be used in grading or ranking, There are no overlaps and nominal scale are mutually exclusive. One can be either Muslim or non-Muslim, not both at the same time as it requires an item to be placed in one and only one class. It is used for counting or cross-tabulation.

Hair could be black or grey, blood can be A,B,O or AB. In cricket, there is left arm or right arm spinners.

It is used for obtaining personal data and is usually exhaustive to include all categories or segmentation.

## ORDINAL

It used for ranking, rating or grading. It can show best to worst status or first to last preference. But distance between two ordinal scales is not the same. income level of poor, middle and rich class are like less than Rs.10,000, between Rs.11,000 to Rs.50,000 and 51,000 and above. The distances are 10,000, 39,000 and infinitve respectively.

It is evident that ordinal scale can rank some items in an order like less than or more but not “how much more”

## INTERVAL

It is more powerful than nominal and ordinal as it not only orders or ranks or rates but also shows exact distances in between. But it does not start from zero. If there is zero like zero temperature it is not natural but arbitrary as 0 degree does not mean no temperature. Likewise, year 0 in a forecast is the end of construction year.

This scale is used in addition or substraction of scale value to calculate mean, range, variance, standard deviation, correlation and regression.

Difference between interval and ordinal scale:

Ordinal scale only ranks but does not measure difference between the two ranks like “satisfactory” and “not-satisfactory”. Interval scale not only ranks but also give exact distance between them by assigning a value. Difference in temperature of 20 degree and 40 degree is 20 but 40 is not double hot than 20.

## RATIO SCALE

This scale can perform all functions. It can show all mathematical and geographical indicators. It is useful when exact figures are required in objective matters are required.

If a person is drawing a salary of Rs.20,000 and another Rs.40,000, it can be said that the latter is getting double the salary of the former.

## FOUR SCALES COMPARED

NOMINAL
ORGINAL
INTERVEL
RATIO
Classification but no order, distance or origin
Classification but order but no distance or unique origion
Classificatiion, ordered and distance but no unique origin
Classification, order, distance and unique origin
Determinition of equality
Determinination of greater or lesser value
Determination of equlity of intervals or differences
Determination of equality of ratios
Only Label
equal grouping
Weight, hieght
Gener (male, female)
Doneness of meat, (well, medium well, medium rare, rare)
temperature in degrees
Age in years
Counting
Frequency Distribution
Addition/substraction but no multiplication or division
All functions
Black & While
AAA, BBB, CCC
personality measure
Can say no measurable value like zero sales
Religion
Levels, one-star & 4-star
Mean, range, variance, standard deviation
Annual Income

## types of scales

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## RATING SCALES

Requires the respondent to estimate the magnitude of a quality that an object possesses. Scoring an object without making a direct comparison to another object.

• DICHOTOMOUS
• LIKERT SCALE
• SEMANTIC DIFFERENTIAL SCALE
• GRAPHIC SCALE
• Staple Scale

RANKING SCALES

Requires that the respondents rank order a small number of activities, events or objects on the basis of overall preference or some characteristic of the stimulus.

• PAIRED COMPARISON
• FORCED CHOICE
• COMPARATIVE SCALE

## RANKING AND RATING

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## Validity and Reliability

In business research, all measurements should be both valid and reliable. Validity is relevancy and appropriateness of measuring instrument or scale. While we can judge the health of a child by use of weighing machine, we cannot use the same machine for checking his or her intelligence. The weighing machine is only valid for weighing. When we say is this machine reliable, we mean to say that it would give true measure whenever it is used.

## VALIDITY AND RELIABILITY

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## VALIDITY

More formally, Cook and Campbell (1979) define the validity as the "best available approximation to the truth or falsity of a given inference, proposition or conclusion."

Validity is the strength of our inferences and conclusion. If we cannot decide which instrument is valid for measuring our concept, we may ask the experts. If experts validate it, we can accept it on its face value. Or we go through the contents and find its validity. A training program for enhancing math skills in students should have plus, minus, multiplication and division aspects.

For testing validity of an instrument we can test it ability to predict. Opinion polls forecast outcome of the election. With necessary feedback, we can improve the questionnaire seeking opinion to predict as precisely as possible. SAT determines GPA in MBA. We can correlate SAT result and GPA result to see any association. If we do find, we can insist on having SAT for admission in MBA.

Similarly, an agency responsible for giving un-employment allowance should be able to make distinction among parasites and genuine job seekers. The person preparing the test method can be given 10 people, of which 3 are known parasites. If the test can point them out, it is valid test. Finally, a test for driving is valid which covers both driving skills, through a machine test, and sign recognition. If results from both tests are highly correlative or converge at the same conclusion, these are valid tests.

## RELIABILITY

The instrument should be reliable. A weighing machine which gives different results in different attempts is not reliable. The measurement should stable and consistence. For stability, we can repeat the same test for a number of times. It should give more or less the same results of each participant. Or we may make two alternate forms of the same measure and administer simultaneously or with some delay. There should be high correlation between the two tests. In another method, a test based on 50 true or false questions can be split into two halves and it would be expected that results from the both would the same.

NEXT HUB: Data Collection Methods

## More by this Author

Rufi Shahzada 6 years ago from Karachi

Dear Sir,

I have read both the OPERATION DEFINITION and this HUB in sequence, each and everything is explained so precisely.

I would say this an outstanding FOC Knowledge Base!

Thanks Again!

hafeezrm 6 years ago from Pakistan Author

Thanks Rufi

Syed Najaf Ali 6 years ago

Dear sir..

i have read the Article..Great work sir.. every topic is explained in a precise and clear manner..

Minhas Ahmed 6 years ago

Dear Sir.....great work.... this really eliminated biasing situation during the research work.... it has cleared many concepts and provide vision for Us...in MBR

Ovais Umerkhel 6 years ago

R/Sir,

thnx a lt sir for such an elaborate and simple explanation on the topic, really useful for business graduates who study the subject as a partial subject. However i m stil unable to operationalization and measurement scales? looking forward to get ur kind guidance.

thnx again!

hafeezrm 6 years ago from Pakistan Author

Dear Ovais Umerkhel,

Please visit this hub for operational and conceputal defintion:

http://hubpages.com/education/Case-Study-an-Operat...

neelam 6 years ago

waho great artical............ me sad learned more from this

thanks

komickyprof 5 years ago

thanks so much for this explanation; its really helped me a lot in my assignments and research work. Hoping to see more of this great work from u.

Thank u

God bless u

GP 5 years ago

Good work

Shafie Sharif 4 years ago

Thanks Dr. You did great job and You contributed our knowledge.

hafeezrm 4 years ago from Pakistan Author

Invanet Atieno 4 years ago

Thanks 4 helping me understand what i could not get in class.Keep it up

bharti dewangan 4 years ago

it was realy helpful while preparing for my exmz.

hafeezrm 4 years ago from Pakistan Author

Mr.The 4 years ago

Dear Sr...

i was have a problem in starting my Experiment of Measurement collection data of tea. i wonder you can help me or tell me a book that i can read to understand the problem.

Thank you!

hafeezrm 4 years ago from Pakistan Author

Please go through this hub again. All pertinent information is given.

http://hubpages.com/education/Data-Collection-Meth...

Mr.The 4 years ago

Thank Sr!

shoaib 3 years ago

gooD work siR