This document discusses data collection and classification. It defines primary data as data originally collected for the first time through methods like personal interviews, questionnaires, and observation. Secondary data comes from existing sources like published books, journals, and newspapers. There are two main types of classification - qualitative, which organizes data by descriptive attributes, and quantitative, which organizes data numerically as discrete or continuous variables. The objectives of classification are to simplify complex data, establish relationships between series, and present information in a condensed form.

2. UNIT 1:
INTRODUCTION
TO STATISTICS
PART - II

4. • The process of counting or enumerating and
recording the same systematically is called
“Collection of data”.
• Census or Sample technique is adopted in
collecting the “Primary” data. The Collected raw
data is edited and scrutinized by detecting the
errors and omitting the irrelevant and inconsistent
information.

5. Sources of Collecting the
data

6. Primary Sources
• The data which are originally collected for the first
time are called as “Primary Data”.

8. Types of primary data

9. Direct
personal
inteview

10. Indirect oral
interview

11. Local
Agencies

12. Observation

13. Questionnaires

14. Schedules

15. Secondary Sources
• Published books
• Journals
• Internet
• News papers
• Articles

18. Objectives of
classification
1. To eliminate unnecessary detail of the data.
2. To convert the raw data into an organised data.
3. To present the complex data into a simple form.
4. To bring out similarity and dissimilarity in the
items.
5. To bring in uniformity among the facts.
6. To present the data in a condensed form.
7. To establish relationship between the two series.

19. TYPES OF CLASSIFICATION
Qualitative (Descriptive / Attributes)
Simple
Composite
Arbitrary
Quantitative (Numerical / Variables)
Discrete
Continuous

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