Sem-i_presentation Of Data

Presentation of Data

Introduction to Data

Rohit Vishal Kumar Reader, Department of Marketing Xavier Institute of Social Service P.O. Box No: 7, Purulia Road Ranchi – 834001, Jharkhand, India

What is Data?


Data:










Types of Data


Data refers to unorganized information Datum – refers to a single piece of Information

Data is the measurement (or outcome) of an experiment. This is frequently referred to “raw data”. Data is processed to get information A collection of data is referred to as “data-set” Height of 10 college going students in cm 140.90 159.10

161.20 147.20

153.90 773.50

172.20 181.50

Primary Data:





Data collected primarily for the purpose of the given enquiry are called primary data

Secondary Data:


Data which has been collected by some other agencies (either Government or Private) and exist in published or unpublished form is known as secondary data

162.90 1590.0

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Collection of Data


Complete Enumeration:









Each and every individual of the group to be surveyed is covered and the information is collected for each individual separately Leads to greater accuracy in analysis Is time-consuming, costly and at times impractical





A subset of individuals (called the sample) which are representative of the group to be surveyed is covered and the information is collected only for the sample Low accuracy, but gives sufficiently accurate results Requires knowledge of statistics to do it correctly

Scrutiny of Data


Collected data should be checked for errors before being used in analysis


The Questionnaire Method:


















Non Frequency Data





Errors of date



















Values of the variables are given for different individual in a group for the same period of time E.g. : Height, weight and Sex composition of babies born in May ’06 in the various districts of Jharkhand

Frequency Data


Find the error in the following data

Values of the variables are given for different period of time E.g. : Food grain production in India for the last twelve month

Spatial Series (Longitudinal) Data


E.g. : Age of father 45, Age of Son 30 E.g. : Output of a factory on 2nd October 2006

Time Series (Historical) Data


E.g. : 107 or 707

Improbable (but not impossible)

Respondent not told that he is under observation Investigator observes and records response

Types of Data Series

E.g. : 10.97 or 109.7




Questionnaire NOT GIVEN to the respondent Investigator asks the questions and records responses

Method of Direct Observation


Errors due to wrong recording


Questionnaire GIVEN to the respondent for filling up Investigator collects the filled in questionnaire

The Interview Method:

Errors due to decimal point shifting











Sampling:


Methods of Data Collection

Data in which the “characteristics” formed by a group of individuals is of interest. Frequency of occurrence is important


E.g. : IQ of a group of class 10 students

2

Textual Presentation

Types of Data Presentation

“Total geographical area of India is about 329 mn hectare, but statistical information is available for only 305 mn hectare. 41 mn hectare of the total reporting area is classified as barren land and as area under non agricultural use. 67 mn hectare is under forest. Permanent pastures or grazing land is about 12 mn hectare. Cultivable waste land accounts for 19 mn hectare. Fallow land account for a further 30 mn hectare. The net sown area is only 136 mn hectare” CMIE Land Use Statistics 1987-88

Textual Presentation


Advantages:








Appeals to people with analytical bent of mind Allows all details to be explored Attention can be focused on special issues Normally employed in official reports

Disadvantages



Not very useful for a large mass of data Can become monotonous and boring

Tabular Presentation Stub Describes what is contained in the rows

Title Contains a brief description of the table

Table 2.1 Land Utilization Pattern in India 1987-88

Item 1. Total Geographic Area 2. Total Reporting Area 3. Barren Land 4. Area under forest 5. Permanent Pastures 6. Cultivable waste land 7. Fallow Land 8. Net Sown Area

Area (mn ha) 329 305 41 67 12 19 30 136

Source: CMIE Land Use Statistics, 1987-88

Caption Describes what is contained in the columns

Percentage 100 93 Body Contains the relevant 13 Figures 20 4 6 9 41 Footnote Contains the source and other explanatory material

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Tabular Presentation


Graphical Presentation - Types

Advantages:









Line Diagram:


Shows data in a compact form Puts the information in a clear perspective Does not require explanatory material Enables easy comparison to be made Errors and Omissions can be easily detected







Bar Diagram



Disadvantages



Requires expertise in preparation Wrong presentation can lead to faulty inference

Pie Chart




Pictorial Diagram




Statistical Maps




Line Diagram

Can be used for time series or any other series Variations: Multiple bar chart,










Normally used with time-series data Variations: Log & Semi Log Chart, Band Chart, Multiple Axis Chart

Used for representing percentage Similar to Bar Diagram, uses pictures instead of bars

Bar Diagram

60000

8.00

Rural 7.00

Urban

Kg. per month

Rs. Crores

50000

40000

30000

6.00 5.00 4.00 3.00

20000 2.00 10000

Value of Exports 0

1.00 0.00

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

Fig 1: Value of Indian Exports (including re-exports) in India during 1985-94

Rice

Whe at

Jowar

Bajra

M aize

Fig 2: Average Per Capita Consumption of Cereals per month during 1985-94

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Pie Chart

Pictorial Diagram 0.56

0.52

Kg. per month

0.95

Rice 6.93

Wheat Jowar Bajra Maize

4.7

Fig 2: Average Per Capita Consumption of Cereals per month during 1985-94

Statistical Map

Fig 3: Input needed to produce food energy

Graphical Presentation


Advantages:





Easily understood by laymen

Disadvantages:




Only a limited amount of information can be presented Can only provide a rough idea about magnitude of variation Numerous charts can become boring

Fig 4: Map of India showing Land Types Classification

5

Thank You

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