RBSE Class 11 Economics Notes Chapter 2 Collection of Data

These comprehensive RBSE Class 11 Economics Notes Chapter 2 Collection of Data will give a brief overview of all the concepts.

RBSE Class 11 Economics Chapter 2 Notes Collection of Data

Data and its Sources:

• Data is the plural form of the Latin word ‘datum’, which means a fact or information.
• Data collection is the process of gathering information in order to arrive at an effective solution to an ; economic problem.
• Primary data is the type of data which is collected by the investigator or enumerator from its origin.
• Secondary data are the data which have already been collected and new investigator only uses them for his investigation purpose.

Sources of Data

• Primary source
• Secondary source

Methods of Data Collection

• Direct personal investigation - face to face interviews with the respondents Indirect oral investigation - questions are asked over the telephone
• Local correspondents and resources - data are collected by appointing some local correspondents or from local source
• Questionnaires through Enumerators - sent through the enumerator to fill the required data or information
• Questionnaire through Mail Method - sent through the mail with an enclosed letter describing the details of investigation and requesting a return

Types of Questions in Questionnaire

1. Open-ended questions
2. General option questions
3. Multiple choice questions
4. Special informative questions

Pilot survey is conducted with a small group to know the drawbacks and shortcomings of the questions.

Census and Sample Methods
In statistics, universe or population simply refers to aggregate of items to be studied in an investigation. In Census method, data related to investigation are collected with reference to each item of universe and conclusions are drawn on that basis.

Major agencies in India which collect, process and tabulate statistical data are:

• Census of India ;
• National Sample Survey Organisation (NSSO)
• Central Statistical Organisation (CSO)
• Registrar General of India (RGI)
• Directorate General of Commercial Intelligence and Statistics (DGCIS) 
• Labour Bureau
  • The Census of India is carried out every ten years.
  • The first Census after independence was held in 1951.
  • The last Census of India was held in February, 2011.
  • NSSO conducts nationwide surveys on socio-economic issues. 
  • A sample refers to a group or section of the population from which information is to be obtained.
  • In sample method, a sample is taken out of population that represents the entire population.

Methods of Sampling

• Random sampling - individual units are selected at random ;
• Purposive sampling - sample is chosen which the investigator thinks best represent the whole population
• Stratified sampling - a mixture of random and purposive sampling 
• Systematic sampling - randomly selected sample is classified on the basis of certain characteristics 
• Quota sampling - sample is selected on the basis of quota ;
• Convenience sampling - sample is selected as per enumerator’s convenience ;

Statistical Errors

• Statistical errors are of two types: sampling errors and non-sampling errors. ;
• Sampling error occurs when there is a difference between the sample estimate and the actual value of the variable under consideration.
• Non-sampling errors are more serious than sampling errors.

Types of Non-sampling Errors:

• Errors in data acquisition
• Non-response errors
• Sampling bias