Collection of Data
Class 11 · Economics
4 ideas in Class 11 Economics, explained in plain words, with games and quizzes to practise.
Census versus Sampling
Part of: Sources and Sampling
Census covers all units; samples study few; random gives equal chance; lottery and tables pick fairly; errors shrink with design.
Why it matters. Coverage costs money. Randomness buys fairness.
Key words
- Census
- : Studying every unit of the population.
- Sampling
- : Studying a representative few units.
- Random sampling
- : Every unit holding an equal selection chance.
- Lottery method
- : Blind slip draw picking a fair sample.
- Sampling error
- : Error from studying a part instead of all.
- Non-sampling error
- : Error from faulty questions or wrong replies.
Try it in two minutes
- Count the budget.
- Pick random units.
- Check the errors.
Try at home. Lottery-pick class members.
Questionnaires
Part of: Sources and Sampling
Short simple words avoid confusion; leading and double questions bias; sequences flow general to specific; pilot surveys pre-test drafts.
Why it matters. Wording shapes answers. Pretests catch flaws.
Key words
- Good question
- : Short clear wording avoiding confusion.
- Leading question
- : Wording pushing the respondent to one answer.
- Double question
- : Two queries packed into one answer slot.
- Pilot survey
- : Trial run of the draft on a small group.
- Open-ended question
- : Free own-word replies without fixed choices.
- Sensitive handling
- : Income asked in slabs, not exact figures.
Try it in two minutes
- Write short queries.
- Cut bias words.
- Pilot the draft.
Try at home. Draft a snack survey.
Modes of Collection
Part of: Methods and Sources
Personal interviews probe deep but cost more; mail covers wide but returns thin; phones speed but skip the unconnected; enumerators bridge illiteracy.
Why it matters. Modes trade cost, depth and reach. Enumerators aid the unschooled.
Key words
- Personal interview
- : Face-to-face probing with high response.
- Mail survey
- : Wide postal reach weakened by thin returns.
- Phone survey
- : Fast calls suited to short simple queries.
- Enumerator
- : Field staff reading and recording for illiterates.
- Investigator bias
- : Slant from untrained or leading investigators.
Try it in two minutes
- Weigh cost versus depth.
- Match mode to people.
- Train enumerators.
Try at home. Phone-survey friends.
Official Sources
Part of: Methods and Sources
Census counts all each decade; NSSO surveys samples yearly; CSO compiles national accounts; RBI reports money; check reliability, relevance, recency.
Why it matters. Official data anchors research. Source checks prevent misuse.
Key words
- Indian census
- : Full population count taken every ten years.
- NSSO
- : Body running yearly sample surveys.
- CSO
- : Office compiling national income accounts.
- RBI
- : Bank publishing money and banking data.
- Secondary data
- : Already published data reused for study.
- Three R checks
- : Reliability, relevance and recency tests for reuse.
Try it in two minutes
- Name the agency.
- Check the year.
- Match the need.
Try at home. Find census population.
What your child will practise
- Census versus Sampling: Desert Puzzle (Clue Puzzle)
- Census versus Sampling: Desert Quick Fire (Quick Fire)
- Modes of Collection: Space Puzzle (Clue Puzzle)
- Official Sources: Desert Quest (Flip and Match)
- Questionnaires: Jungle Quick Fire (Quick Fire)
- Quiz: Census versus Sampling (8 questions)
- Quiz: Modes of Collection (8 questions)
- Quiz: Official Sources (8 questions)
- Quiz: Questionnaires (8 questions)