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Unit 9: Attitude Measurement and Scaling Techniques
(b) Width of the class interval: Class interval should be uniform and should be of equal Notes
width. This will provide consistency in the data distribution.
(c) Exclusive categories: The classification should be done in such a way that the response can
be placed in only one category.
Example: Problem of leg room is the answer by respondent. This should be placed either
under discomfort or design, but not both.
(d) Exhaustive categories: This should be made to include all responses including “Don’t
Know” answers. Sometimes this will influence the ultimate answer to the research problem.
(e) Avoid extremes: Avoid open-ended class interval.
Usage of Statistical Tools
Frequency Distribution: Frequency distribution simply reports the number of responses that
each question receives. Frequency distribution organises the data into classes or groups. It
shows the number of data that falls into particular class.
Example:
Income No. of people
4000-6999 100
7000-9999 122
10000-12999 140
In marketing research, central value or tendency plays a very important role. The researcher
may be interested in the average sales/shop, average consumption per month etc. The population
parameters can be calculated with the help of simple average. The average of sample may be
taken as population parameter. For example, if the average income of the population is to be
computed, the researcher may select a sample, collect data on family income and calculate the
relevant statistics which will be a representative of the population.
The total purchasing power of the community can be estimated on sample average. If the sample
is stratified, the purchasing power of each income class may also be estimated. The median
figure will reveal that half the population has more income than the median income, and the
others half has less income than the median income. The mode will reveal the most common
frequency. Based on this, shoppers can devise their strategy to sell the product.
The three most common ways to measure centrality or central tendency are the mode, median
and mean.
Mode
The mode is the central value or item that occurs most often, when data is categorized in a
frequency distribution, it is very easy to identify the mode, since the category in which the mode
lies has the greatest number of observations.
Example: Data regarding household income of 300 people as tabulated by the researcher.
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