Day Six Slide Unit Two

7/28/2019 Day Six Slide Unit Two

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L a x m a n P o k h r e lm a i l @ l a x m a n p o k h r e l . c o m . n p / l a x . p o k @ g m a i l . c o mC e l l : 9 8 5 1 0 3 7 8 9 7

Research Methodology

Date:28th August,2012

Day 6


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C h a p t e r 2

The Importance OFMeasurement in Research Day 6

Date:28th August,2012


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Unit 2:Levels of Measurement

Four Levels of Measurement Nominal

Ordinal Interval Ratio

Level of Measurement


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Nominal Measurement A nominal scale enables the classification of individuals, objects or

responses into subgroups based on a common/shared property orcharacteristic.

A variable measured on a nominal scale may have one, two or moresubcategories depending upon the extent of variation

Nominal scales focus on only requiring a respondent to provide sometype of descriptive data as the raw response

For example, water or tree have only one subgroup, whereas the

variable gender can be classified into two sub-categories: male andfemale. Hotels can be classified into ---- sub-categories.



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Nominal Measurement Statistical operations like frequency, percentage,

proportion, mode of coefficient of counting of

contingency, addition, subtraction, multiplicationand division are not applied This is also called attributes or qualitative

characteristics such as age, sex, eye color,religion, nationality etc.

No ordering of the cases is implied. For example, jersey numbers in basketball are measures at thenominal level. A player with number 30 is notmore of anything than a player with number 15,and is certainly not twice whatever number 15 is



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Nominal Measurement

Some Examples of Nominal data Gender: Male, Female Religion: Hindu, Buddhist, Muslim, Christian Occupation: Teacher, Manager, Doctor,

Businessman, Civil Servant Nationality: Nepali, Indian, American, Japanese Department: Sales, Finance, Personnel,

Production.



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Nominal Measurement

Example.

Please indicate your current martial status. __Married __ Single

__ Single, never married __ Widowed



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Ordinal Measurement Besides categorizing individuals, objects, responses or a

property into subgroups on the basis of common characteristic,it ranks the subgroups in a certain order.

They are arranged either in ascending or descending order according to the extent a subcategory reflects the magnitudeof variation in the variable.

Ordinal scales allow the respondent to express relativemagnitude between the raw responses to a question

For example , income can be measured either quantitatively(in rupees and paisa) or qualitatively using subcategoriesabove average, average and below average. The distance between these subcategories are not equal as there is noquantitative unit of measurement.



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Ordinal Measurement The numbers are arranged from highest to lowest, or

from lowest to highest order, and reflects thecomparison in terms of higher or lower, heavier orlighter, harder to softer etc.

For example, students may be ranked 1st, 2nd, 3rdetc. in terms of their academic achievements toconstitute the example of ordinal measurement

The relationship of equivalence, greater than or lesserthan exists, because all members of any particularsubclass or equivalent to each other and at the sametime greater or lesser then the member of otherclasses

The permissible statistical operations in ordinal

measurements are median, percentile, rank,correlation coefficients



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Ordinal Measurement

Example.

Which one statement best describes your opinion of Ncell

mobile? __ Better than NTC __ About the same as NTC __ Lower than NTC

Another example:

In a survey you might code Educational Attainment as 0=lessthan H.S.; 1=some H.S.; 2=H.S. degree; 3=some college;4=college degree; 5=post college. In this measure, highernumbers mean more education. But is distance from 0 to 1 sameas 3 to 4? Of course not. The interval between values is notinterpretable in an ordinal measure.



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Interval Measurement An interval scale has all the characteristics of an ordinal scale.

In addition, it uses a unit of measurement with an arbitrary

starting and terminating points. Interval scales demonstrate the absolute differences between

each scale point For example , Celsius scale: 0*C to 100*C Fahrenheit scale:

32*F to 212*F A temperature of 50 degrees is exactly 10 degrees hotter than

40 degrees and 10 degrees cooler than 60 degrees.



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Interval Measurement Interval data can be measured and compared by addition and

subtraction because each point on the scale is an equal distance. Thecommon statistics used in such measurements are arithmetic mean,standard deviation, Pearsons correlation coefficient and otherstatistics based upon them. Also T and F test are used to test thesignificance of the characteristics.

In interval measurement the distance between attributes does havemeaning. For example, when we measure temperature (in

Fahrenheit), the distance from 30-40 is same as distance from 70-80. The interval between values is interpretable. Because of this, it makessense to compute an average of an interval variable, where it doesn'tmake sense to do so for ordinal scales



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Interval Measurement

Example.

How likely are you to recommend the ABCteacher for the MBA program at LBEF?

Definitely will not Definitely will

0123456789



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Ratio Measurement

A ratio scale has all the properties of nominal, ordinal and intervalscales plus its own property: the zero point of a ratio scale is fixed,which means it has a fixed starting point. Since the difference betweenintervals is always measured from a zero point, this scale can be usedfor mathematical operations.

Ratio scales allow for the identification of absolute differences betweeneach scale point, and absolute comparisons between raw responses.

The measurement of variables like income, age, height and weight areexamples of this scale. A person who is 40 year old is twice as old asone who is 20 year old.



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Ratio Measurement

Example 1.

Please circle the number of children under 18years of age currently living in your household. 0 1 2 3 4 5 6 7 (if more than 7, please

specify ___.)



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Unit 2:Levels of Measurement: in Summary



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Queries? Next class suggested readings Characteristics of Good

Measurement. Reliability and Validity

Thank You

Unit 2: The Importance OF Measurement in Research

Day Six Slide Unit Two

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Transcript of Day Six Slide Unit Two