Afjal HossainAssistant ProfessorDepartment of Marketing, PSTU

Chapter 02Collection of Data

Sources of Data

PrimaryData(PrimarySource)

Data obtained from the original sources are known PrimaryData. This type of data is used to solve the problem at hand.These types of data are collected from the individualrespondents or field.

SecondaryData(Secondarysource)

Data which has already been discovered/ collected by others areSecondary Data. These types of data can be obtained fromjournals, reports, government publications, publications ofresearch organizations etc.

InternalData(InternalRecords)

Internal Data are the measurements that are the by-product ofroutine business record keeping. Ex: accounting, finance,production, personnel, quality control, sales, R & D etc.

Questionnaire Design

1. Specify the information needed2. Specify the Type of Interviewing method3. Determine the Content of Individual Questions4. Design the Questions to overcome the respondent’s

inability and unwillingness to answer5. Decide on the Questions Structure6. Determine the Question Wording7. Arrange the Questions in Proper Order8. Identify the Form and Layout9. Reproduce the Questionnaire10.Eliminate Bugs by Pretesting

Workshop 1

▪ Fair and Handsome removes the dust as well as keep skin fresh. What do you think?

❖ Highly Disagree

❖ Disagree

❖ Neutral

❖ Agree

❖ Highly agree

Identify the type of questionnaire with reasons.

Workshop 2

Identify the type of questionnaire with reasons.

1. Prefer women to see on TV:ОYes О No О Undecided

2. Preference for prime-time evening program:

ОYes О No

3. Do you think the image of minorities is accurately presented in the media of Bangladesh?

Classification of Data

Geographical Data(Area-wise)

The data are classified on the basis ofgeographical or locational differences betweenthe various items are geographical data. Ex: Theproduction of rice in different countries.

Chronological Data(Time-basis)

The data observed over a period of time arechronological data. Ex: Sales figure of a companyin different years.

Qualitative Data(Attribute-based)

Data are classified on the basis of some attributesor qualities are qualitative data. Ex: Sex, Color,Literacy and Religion etc.

Quantitative Data(Magnitude-based)

Data are the characteristics which can bemeasured. Ex: Height, Weight, Sales etc.

Formation of Frequency Distribution

1. Title & Subtitle

2. Class (Class Limits and Class Intervals)

3. Tally

4. Frequency

5. Foot note (if any)

Additional:

1. Mid-point Class

2. Cumulative Frequency

Formation of Class

Inclusive Class: When the lower & upper value

of a class are included in the class.

Exclusive Class: When the upper value of a

class will be included in the next class.

Exercise 1

▪ Prepare a frequency distribution for a leading agency in the year of 2013 ended of the number of refrigerators sold on 22 working days in the following:

23, 30, 20, 26, 30, 30, 20, 23, 40, 40, 26, 20, 23, 40, 28, 26, 23, 30, 40, 28, 28 and 30.

Exercise 2 (Problem 12, P78)

▪ Form a frequency distribution taking a suitable class-interval for the following data giving the age of 52 employees in a government agency.

67, 34, 36, 48, 49, 31, 61, 34, 43, 45, 38, 32, 27, 61, 29, 47, 36, 50, 46, 30, 46, 32, 30, 33, 45, 49, 48, 41, 53, 36, 37, 37, 47, 30, 46, 50, 28, 35, 35, 38, 36, 46, 43, 34, 62, 69, 50, 28, 44, 43, 60 and 39.

Exercise 3

▪ Prepare a frequency distribution for the profits (in lac of Tk.) of 30 companies for the year 2012-2013 in the following:

20, 22, 35, 42, 37, 42, 48, 53, 49, 65, 39, 48, 67, 18, 16, 23, 37, 35, 49, 63, 65, 55, 45, 58, 57, 69, 25, 29, 58, and 65.

Workshop 1

Identify the type of data with reasons.1. The population of Bangladesh can be divided

under blinds and non-blinds.2. Sales figures of a Akij food and beverage is:

3. The value of 45 for the class 40-50 is ------?4. For large number of data what kind of

frequency distribution is much more easier to prepare?

Year Sales (Lac Tk.)

2010-2011 206

2011-2012 350

2012-2013 490

Presentation of Data

▪ Table i.e. Frequency distribution (inclusive and/or exclusive class interval)

▪ Chart1. Diagram

a) One dimensional or Bar diagramb) Two dimensional diagram i.e. rectangle, squarec) Pictograms and Cartograms

2. Grapha) Line graphb) Graph for frequency distribution

i. Histogramii. Frequency polygoniii. Cumulative frequency curve or “Ogives”

Diagram

a) One dimensional or Bar diagram

It is a thick line whose width is shown merely for attention. It is only length of the bar but not the width.

Diagram

b. Two dimensional diagram i.e. rectangle, square

In two dimensional diagrams the lengths as well as the width of the bars is considered. Also known as Surface diagrams or Area diagrams.

Diagram

c. Pictograms

In pictograms data are presented through a pictorial symbol. It is known as Picturegrams.

d. Cartograms

In cartograms data are presented through a map on a geographical basis. It is also known as Statistical maps.

Cartograms

Graph

a) Line graph

When we take the time on X-axis and value of the variable on Y-axis and joined the various points by straight lines then it is called line graph.

Graph

b. Graph for frequency distributioni. Histogram

A histogram is a graphical method for presenting data where the variables (class interval) are located on a horizontal (X-axis) axis and frequencies are located in the vertical (Y-axis) axis. It is also known as Column diagrams.

Graph

b. Graph for frequency distributionii. Frequency polygon

Drawing a histogram of the given data, and then join by straight lines the mid-points of the upper horizontal side of each rectangle with the adjacent rectangle is called frequency polygon.

Some statisticians prefer to close both the ends of the polygon by extending them to the base line.

Graph

b. Graph for frequency distributioniii. Cumulative frequency curve or “Ogives”

Two methods of constructing Ogives: Less than method and More than method

Less than method: We starts with the upper limits of the classes and go on adding the frequencies. When these frequencies are plotted we get a rising curve.

Graph

b. Graph for frequency distributioniii. Cumulative frequency curve or “Ogives”

Two methods of constructing Ogives: Less than method and More than method

More than method: We starts with the lower limits of the classes and form the total frequencies we subtract the frequency of each class. When these frequencies are plotted we get a declining curve.

Workshop 1

▪ Prepare a histogram, more than ogive curve for the following data considering a frequency distribution:

30, 45, 15, 20, 35, 50, 70, 45, 50, 50, 55, 65, 70, 30, 25, 34, 34, 45, 42, 48, 58, 68, 70, 15, 18, 20, 25, 60, 55, 58, 43, 46, 49, 50, 51, 52, 58, 42, 28 and 40.