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Tuesday, December 13, 2011

Scaling

                scaling is the process of measuring or ordering entities with respect to quantitative attributes or traits. For example, a scaling technique might involve estimating individuals' levels of extraversion, or the perceived quality of products. Certain methods of scaling permit estimation of magnitudes on a continuum, while other methods provide only for relative ordering of the entities.

Types of Scales  : Most frequently used Scales

1.     Nominal Scale     b. Ordinal Scale  c. Interval Scale e. Ratio Scale
Self Rating Scales
1.     Graphic Rating Scale  
2.     Itemized Rating Scales
a.     Likert Scale    b. Semantic Differential Scale  c. Stapel’s Scale   d.  Multi Dimensional Scaling
b.     e.Thurston Scales  f. Guttman Scales/Scalogram Analysis    g.The Q Sort technique
Four types of scales are generally used for Marketing Research.
1.    Nominal Scale
This is a very simple scale. It consists of assignment of facts/choices to various alternative categories which are usually exhaustive as well mutually exclusive. These scales are just numerical and are the least restrictive of all the scales. Instances of Nominal Scale are - credit card numbers, bank account numbers, employee id numbers etc. It is simple and widely used when relationship between two variables is to be studied. In a Nominal Scale numbers are no more than labels and are used specifically to identify different categories of responses. Following example illustrates -
What is your gender?    [  ] Male    [  ] Female
Another example is - a survey of retail stores done on two dimensions - way of maintaining stocks and daily turnover.
How do you stock items at present?
[  ] By product category   [  ] At a centralized store   [  ] Department wise    [  ] Single warehouse
Daily turnover of consumer is?
[  ] Between 100 – 200    [  ] Between 200 – 300    [  ] Above 300
A two way classification can be made as follows
Daily/Stock Turnover Method
Product Category
Department wise
Centralized Store
Single Warehouse
100 – 200




200 – 300




Above 300




1.    Ordinal Scale
Ordinal scales are the simplest attitude measuring scale used in Marketing Research. It is more powerful than a nominal scale in that the numbers possess the property of rank order. The ranking of certain product attributes/benefits as deemed important by the respondents is obtained through the scale.
Example 1: Rank the following attributes (1 – 5), on their importance in a microwave oven.
a.     Company Name  b. Functions c. Price  d.Comfort   e.Design
The most important attribute is ranked 1 by the respondents and the least important is ranked 5. Instead of numbers, letters or symbols too can be used to rate in a ordinal scale. Such scale makes no attempt to measure the degree of favourability of different rankings.
Example 2 – If there are 4 different types of fertilizers and if they are ordered on the basis of quality as Grade A, Grade B, Grade C, Grade D is again an Ordinal Scale.
Example 3 – If there are 5 different brands of Talcom Powder and if a respondent ranks them based on say, “Freshness” into Rank 1 having maximum Freshness Rank 2 the second maximum Freshness, and so on, an Ordinal Scale results.
2.    Interval Scale
Herein the distance between the various categories unlike in Nominal, or numbers unlike in Ordinal, are equal in case of Interval Scales. The Interval Scales are also termed as Rating Scales. An Interval Scale has an arbitrary Zero point with further numbers placed at equal intervals. A very good example of Interval Scale is a Thermometer.
Illustration 1 – How do you rate your present refrigerator for the following qualities.
Company Name
Less Known
1
2
3
4
5
Well Known
Functions
Few
1
2
3
4
5
Many
Price
Low
1
2
3
4
5
High
Design
Poor
1
2
3
4
5
Good
Overall Satisfaction
Very Dis-Satisfied
1
2
3
4
5
Very Satisfied
Such a scale permits the researcher to say that position 5 on the scale is above position 4 and also the distance from 5 to 4 is same as distance from 4 to 3. Such a scale however does not permit conclusion that position 4 is twice as strong as position 2 because no zero position has been established. The data obtained from the Interval Scale can be used to calculate the Mean scores of each attributes over all respondents. The Standard Deviation (a measure of dispersion) can also be calculated.
1.    Ratio Scale
Ratio Scales are not widely used in Marketing Research unless a base item is made available for comparison. In the above example of Interval scale, a score of 4 in one quality does not necessarily mean that the respondent is twice more satisfied than the respondent who marks 2 on the scale. A Ratio scale has a natural zero point and further numbers are placed at equally appearing intervals. For example scales for measuring physical quantities like – length, weight, etc.
The ratio scales are very common in physical scenarios. Quantified responses forming a ratio scale analytically are the most versatile. Rati scale possess all he characteristics of an internal scale, and the ratios of the numbers on these scales have meaningful interpretations. Data on certain demographic or descriptive attributes, if they are obtained through open-ended questions, will have ratio-scale properties. Consider the following questions :
Q 1) What is your annual income before taxes? ______ $
Q 2) How far is the Theater from your home ? ______ miles
Answers to these questions have a natural, unambiguous starting point, namely zero. Since starting point is not chosen arbitrarily, computing and interpreting ratio makes sense. For example we can say that a respondent with an annual income of $ 40,000 earns twice as much as one with an annual income of $ 20,000.

Self rating scales

1.    Graphic Rating Scale
The respondents rate the objects by placing a mark at the appropriate position on a line that runs from one extreme of the criterion variable to another. Example

0
(poor quality)
1
(bad quality)
5
(neither good nor bad)
7
(good quality)
BRAND 1
This is also known as continuous rating scale. The customer can occupy any position. Here one attribute is taken ex-quality of any brand of icecream.

poor
good
BRAND 2
This line can be vertical or horizontal and scale points may be provided. No other indication is there on the continuous scale. A range is provided. To quantify the responses to question that “indicate your overall opinion about ice-ream Brand 2 by placing a tick mark at appropriate position on the line”, we measure the physical distance between the left extreme position and the response position on the line.; the greater the distance, the more favourable is the response or attitude towards the brand.
Its limitation is that coding and analysis will require substantial amount of time, since we first have to measure the physical distances on the scale for each respondent.
1.    Itemized Rating Scales
These scales are different from continuous rating scales. They have a number of brief descriptions associated with each category. They are widely used in Marketing Research. They essentially take the form of the multiple category questions. The most common are – Likert, Sementic, Staple and Multiple Dimension. Others are – Thurston and Guttman.
a.    Likert Scale
It was developed Rensis Likert. Here the respondents are asked to indicate a degree of agreement and disagreement with each of a series of statement. Each scale item has 5 response categories ranging from strongly agree and strongly disagree.
5
Strongly agree
4
Agree
3
Indifferent
2
Disagree
1
Strongly disagree
Each statement is assigned a numerical score ranging from 1 to 5. It can also be scaled as -2 to +2.
-2
-1
0
1
2
For example quality of Mother Diary ice-cream is poor then Not Good is a negative statement and Strongly Agree with this means the quality is not good.
Each degree of agreement is given a numerical score and the respondents total score is computed by summing these scores. This total score of respondent reveals the particular opinion of a person.
Likert Scale are of ordinal type, they enable one to rank attitudes, but not to measure the difference between attitudes. They take about the same amount of efforts to create as Thurston scale and are considered more discriminating and reliable because of the larger range of responses typically given in Likert scale.
A typical Likert scale has 20 – 30 statements. While designing a good Likert Scale, first a large pool of statements relevant to the measurement of attitude has to be generated and then from the pool statements, the statements which are vague and non-discriminating have to be eliminated.

a.    Semantic Differential Scale
This is a seven point scale and the end points of the scale are associated with bipolar labels.
1
Unpleasant
Submissive
2
3
4
5
6
7
Pleasant
Dominant
Suppose we want to know personality of a particular person. We have options-
a.     Unpleasant/Submissive
b.     Pleasant/Dominant
Bi-polar means two opposite streams. Individual can score between 1 to 7 or -3 to 3. On the basis of these responses profiles are made. We can analyse for two or three products and by joining these profiles we get profile analysis. It could take any shape depending on the number of variables.
Mean and median are used for comparison. This scale helps to determine overall similarities and differences among objects.
When Semantic Differential Scale is used to develop an image profile, it provides a good basis for comparing images of two or more items. The big advantage of this scale is its simplicity, while producing results compared with those of the more complex scaling methods. The method is easy and fast to administer, but it is also sensitive to small differences in attitude, highly versatile, reliable and generally valid.
b.    Stapel’s Scale
It was developed by Jan Stapel. This scale has some distinctive features:-
a.     Each item has only one word/phrase indicating the dimension it represents.
b.     Each item has ten response categories.
c.     Each item has an even number of categories.
d.     The response categories have numerical labels but no verbal labels.
For example, in the following items, suppose for quality of ice cream, we ask respondents to rank from +5 to -5. Select a plus number for words which best describe the ice cream accurately. Select a minus number for words you think do not describe the ice cream quality accurately. Thus, we can select any number from +5,for words we think are very accurate, to -5,for words we think are very inaccurate. This scale is usually presented vertically.
+5  +4  +3  +2  +1
High Quality
-1  -2  -3  -4  -5
This is a unipolar rating scale.
c.     Multi Dimensional Scaling
It consists of a group of analytical techniques which are used to study consumer attitudes related to perceptions and preferences. It is used to study-
a.     The major attributes of a given class of products perceivedby the consumers in considering the product and by which they compare the different ranks.
b.     To study which brand competes most directly with each other.
c.     To find out whether the consumers would like a new brand with a combination of characteristics not found in the market.
d.     What would be the consumers ideal combination of product attributes.
e.     What sales and advertising messages are compatible with consumers brand perceptions.
It is a computer based technique. The respondents are asked to place the various brands into different groups like similar, very similar, not similar, and so on. A goodness of fit is traded off on a large number of attributes. Then a lack of fit index is calculated by computer program. The purpose is to find a reasonably small number of dimensions which will eliminate most of the stress. After the configuration for the consumer’s preference has been developed, the next step is to determine the preference with regards to the product under study. These techniques attempt to identify the product attributes that are important to consumers and to measure their relative importance.
This scaling involves a unrealistic assumption that a consumer who compares different brands would perceive the differences on the basis of only one attribute.For example, what are the attributes for joining M.Com course. The responses may be –to do PG, to go into teaching line,to get knowledge, appearing in the NET. There are a number of attributes, you can not base decision on one attribute only. Therefore, when the consumers are choosing between brands, they base their decision on various attributes. In practice, the perceptions of the consumers involve different attributes and any one consumer perceives each brand as a composite of a number of different attributes. This is a shortcoming of this scale.
Whenever we choose from a number of alternatives, go for multi- dimensional scaling. There are many possible uses of such scaling like in market segmentation, product life cycle, vendor evaluations and advertising media selection.
The limitation of this scale is that it is difficult to clearly define the concept of similarities and preferences. Further the distances between the items are seen as different
d.    Thurston Scales
These are also known as equal appearing interval scales. They are used to measure the attitude towards a given concept or construct. For this purpose a large number of statements are collected that relate to the concept or construct being measured. The judges rate these statements along an 11 category scale in which each category expresses a different degree of favourableness towards the concept. The items are then ranked according to the mean or median ratings assigned by the judges and are used to construct questionnaire of twenty to thirty items that are chosen more or less evenly across the range of ratings. The statements are worded in such a way so that a person can agree or disagree with them. The scale is then administered to assemble of respondents whose scores are determined by computing the mean or median value of the items agreed with. A person who disagrees with all the items has a score of zero. So, the advantage of this scale is that it is an interval measurement scale. But it is the time consuming method and labour intensive. They are commonly used in psychology and education research.
e.    Guttman Scales/Scalogram Analysis
It is based on the idea that items can be arranged along a continuem in such a way that a person who agrees with an item or finds an item acceptable will also agree with or find acceptable all other items expressing a less extreme position. For example – Children should not be allowed to watch indecent programmes or government should ban these programmes or they are not allowed to air on the television. They all are related to one aspect.
In this scale each score represents a unique set of responses and therefore the total score of every individual is obtained. This scale takes a lot of time and effort in development.
They are very commonly used in political science, anthropology, public opinion, research and psychology.
f.     The Q Sort technique
It is used to discriminate among large number of objects quickly. It uses a rank order procedure and the objects are sorted into piles based on similarity with respect to some criteria. The number of objects to be sorted should be between 60-140 approximately. For example, here we are taking nine brands. On the basis of taste we classify the brands into tasty, moderate and non tasty.
We can classify on the basis of price also-Low, medium, high. Then we can attain the perception of people that whether they prefer low priced brand, high or moderate. We can classify sixty brands or pile it into three piles. So the number of objects is to be placed in three piles-low, medium or high.
Thus, the Q-sort technique is an attempt to classify subjects in terms of their similarity to attribute under study.

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