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Collection of Data

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Summary

Chapter 2: Collection of Data

Summary

  • Purpose of data collection is to provide evidence for solving problems.
  • Primary Data: First-hand information collected through surveys.
  • Secondary Data: Data collected by other agencies.
  • Census: Complete enumeration of the population, conducted every ten years.
  • Sample Surveys: Involves a smaller group selected from the population.
  • Random Sampling: Every individual has an equal chance of selection.
  • Non-Random Sampling: Selection based on judgment or convenience.
  • Sampling Errors: Differences between sample estimates and population parameters.
  • Non-Sampling Errors: Errors due to data acquisition issues, non-response, or bias.

Learning Objectives

  • Understand the meaning and purpose of data collection.
  • Distinguish between primary and secondary sources.
  • Know the modes of data collection.
  • Differentiate between Census and Sample Surveys.
  • Familiarize with sampling techniques.
  • Identify important sources of secondary data.

Common Mistakes & Exam Tips

  • Avoid leading questions in surveys.
  • Ensure clarity and precision in questionnaire design.
  • Be cautious of biases in non-random sampling methods.
  • Understand the implications of sampling and non-sampling errors.

Important Definitions

TermDefinition
Primary DataData collected firsthand through surveys.
Secondary DataData collected by other agencies or sources.
CensusA complete enumeration of the population, conducted every ten years.
SampleA smaller group selected from the population for study.
Random SamplingA sampling method where every individual has an equal chance of being selected.
Non-Random SamplingA sampling method based on judgment or convenience, not giving all individuals equal chance.
Sampling ErrorThe difference between the sample estimate and the population parameter.
Non-Sampling ErrorErrors arising from data acquisition issues, non-response, or bias.

Learning Objectives

Learning Objectives

  • Understand the meaning and purpose of data collection.
  • Distinguish between primary and secondary sources of data.
  • Know the modes of data collection.
  • Differentiate between Census and Sample Surveys.
  • Familiarize with techniques of sampling.
  • Identify important sources of secondary data.

Detailed Notes

Collection of Data

Introduction

  • Purpose of data collection: To show evidence for reaching a sound and clear solution to a problem.
  • Example: Fluctuations in food grain production over the years.

Types of Data

  • Primary Data: Based on first-hand information.
  • Secondary Data: Collected from existing sources.

Modes of Data Collection

  1. Personal Interviews:
    • Face-to-face interaction.
    • Advantages: Clarification of questions, personal contact.
    • Disadvantages: Expensive, time-consuming.
  2. Mailing Questionnaires:
    • Sent to individuals with a request to complete and return.
    • Advantages: Less expensive, access to remote areas.
    • Disadvantages: Low response rates, potential misunderstanding.
  3. Telephone Interviews:
    • Conducted over the phone.
    • Advantages: Cheaper, quicker, allows clarification.
    • Disadvantages: Limited access, potential for influencing responses.

Sampling Techniques

  • Census: Complete enumeration of the population.
  • Sample Surveys: A smaller group selected from the population.
    • Random Sampling: Every individual has an equal chance of selection.
    • Non-Random Sampling: Selection based on judgment or convenience.

Errors in Data Collection

  • Sampling Errors: Differences between sample estimates and population parameters.
  • Non-Sampling Errors: Arise from data acquisition issues, non-response, or bias.

Important Agencies for Data Collection

  • Census of India
  • National Sample Survey (NSS)
  • Central Statistics Office (CSO)

Conclusion

  • Data collection is essential for understanding and analyzing economic issues. The choice of data source and collection method depends on the study's objectives.

Exam Tips & Common Mistakes

Common Mistakes and Exam Tips

Common Pitfalls

  • Misunderstanding Sampling Methods: Students often confuse random sampling with non-random sampling. Ensure you understand that in random sampling, every individual has an equal chance of being selected, while non-random sampling involves bias in selection.
  • Ignoring Non-Sampling Errors: Many overlook the significance of non-sampling errors, which can be more serious than sampling errors. Be aware of issues like non-response errors and data acquisition errors.
  • Leading Questions in Surveys: When designing questionnaires, avoid leading questions that suggest a particular answer. For example, instead of asking, "Don't you think smoking should be prohibited?" ask, "Do you think smoking should be prohibited?"
  • Ambiguous Questions: Questions should be clear and precise. Ambiguous questions can confuse respondents and lead to inaccurate data collection.

Tips for Success

  • Understand Data Collection Methods: Familiarize yourself with different data collection methods such as personal interviews, mailing surveys, and telephone interviews. Know their advantages and disadvantages.
  • Practice Designing Questionnaires: Create sample questionnaires to practice structuring questions effectively. Ensure they are easy to understand and avoid complex wording.
  • Review Sampling Techniques: Make sure you can differentiate between census and sample surveys, and understand when to use each method.
  • Clarify Definitions: Be clear on definitions such as population, sample, sampling error, and non-sampling error. This clarity will help in answering exam questions accurately.

Practice & Assessment

Multiple Choice Questions

A.

Personal interviews

B.

Mailing questionnaires

C.

Telephone interviews

D.

Online surveys
Correct Answer: B

Solution:

Mailing questionnaires is suitable for reaching individuals in remote areas where personal interviews and telephone interviews may not be feasible.

A.

Sampling Bias

B.

Non-Response Error

C.

Data Acquisition Error

D.

Measurement Error
Correct Answer: B

Solution:

Non-response error occurs when a person listed in the sample cannot be contacted or refuses to respond, leading to potential bias.

A.

Sample surveys are less expensive and time-consuming.

B.

Census data is always outdated.

C.

Sample surveys are more accurate than censuses.

D.

Census data is not available for agricultural studies.
Correct Answer: A

Solution:

Sample surveys are preferred because they provide reasonably reliable and accurate information at a lower cost and in a shorter time compared to a census.

A.

It is conducted every five years.

B.

It only collects data on employment rates.

C.

It provides a complete demographic record of the population.

D.

It is conducted by the National Sample Survey Office (NSSO).
Correct Answer: C

Solution:

The Census of India provides a comprehensive demographic record of the population, including various aspects such as size, density, sex ratio, and literacy.

A.

Telephone Interviews

B.

Mailing Questionnaire

C.

Personal Interviews

D.

Online Surveys
Correct Answer: C

Solution:

Personal interviews involve direct interaction between the researcher and the respondent, allowing for clarification and expansion of responses.

A.

It is more expensive than personal interviews.

B.

It limits the ability to clarify questions for respondents.

C.

It may not reach individuals without access to a telephone.

D.

It allows for observation of respondents' reactions.
Correct Answer: C

Solution:

A significant disadvantage of telephone interviews is that they may not reach individuals who do not have access to a telephone.

A.

Every individual has an equal chance of being selected

B.

It is based on the researcher's judgment

C.

It is more expensive than non-random sampling

D.

It always provides accurate results
Correct Answer: A

Solution:

In random sampling, every individual in the population has an equal chance of being selected, which helps in reducing bias.

A.

The use of convenience sampling

B.

The use of a non-random sampling method

C.

The use of random number tables or computer programs

D.

The selection of samples based on judgment
Correct Answer: C

Solution:

Random sampling ensures every individual has an equal chance of being selected by using random number tables or computer programs.

A.

Data collected through personal interviews

B.

Data obtained from published reports

C.

Data sourced from government publications

D.

Data extracted from online databases
Correct Answer: A

Solution:

Primary data is collected first-hand by the researcher through methods such as personal interviews, surveys, or experiments. The other options represent secondary data sources.

A.

Every individual has an equal chance of being selected.

B.

Selection is based on convenience.

C.

It is more expensive than a Census.

D.

It always provides accurate results.
Correct Answer: A

Solution:

In random sampling, every individual in the population has an equal chance of being selected, ensuring a representative sample.

A.

Every individual has an equal chance of being selected.

B.

It involves personal judgment in selecting samples.

C.

It helps in reducing bias in sample selection.

D.

It is often used in exit polls.
Correct Answer: B

Solution:

Random sampling does not involve personal judgment; it ensures every individual has an equal chance of being selected.

A.

It is more costly.

B.

It requires more time.

C.

It introduces bias in selection.

D.

It requires a larger sample size.
Correct Answer: C

Solution:

Non-random sampling introduces bias as not all units have an equal chance of being selected.

A.

Personal Interviews

B.

Mailing Questionnaires

C.

Telephone Interviews

D.

Using Census Data
Correct Answer: D

Solution:

Census data is considered secondary data as it is collected by a governmental agency and not directly by the researcher.

A.

Personal Interviews

B.

Mailing Questionnaire

C.

Telephone Interviews

D.

Online Surveys
Correct Answer: B

Solution:

Mailing questionnaires can reach respondents in remote areas where personal or telephone interviews might not be feasible.

A.

Personal Interviews

B.

Mailing Questionnaire

C.

Telephone Interviews

D.

Online Surveys
Correct Answer: A

Solution:

Personal interviews involve face-to-face interaction between the interviewer and the respondent, allowing for clarification and detailed responses.

A.

To estimate the average income of a region

B.

To collect data from a sample of the population

C.

To collect demographic data from the entire population

D.

To conduct surveys on socio-economic issues
Correct Answer: C

Solution:

A Census involves collecting data from every individual in the population to gather comprehensive demographic information.

A.

Sampling error

B.

Non-sampling error

C.

Data acquisition error

D.

Non-response error
Correct Answer: A

Solution:

Sampling error can be minimized by taking a larger sample, whereas non-sampling errors are not easily reduced by increasing sample size.

A.

To collect data from the entire population

B.

To pre-test the questionnaire and identify issues

C.

To finalize the sample size

D.

To conduct the final survey
Correct Answer: B

Solution:

A pilot survey is conducted to pre-test the questionnaire, identify any issues, and make necessary adjustments before the final survey.

A.

Sampling error

B.

Non-response error

C.

Data acquisition error

D.

Sampling bias
Correct Answer: A

Solution:

Sampling error, which is the difference between the sample estimate and the population parameter, can be reduced by increasing the sample size. Non-sampling errors like non-response or data acquisition errors are not reduced by larger samples.

A.

Error due to the difference between sample estimate and population parameter

B.

Error that occurs when some members of the target population cannot be included in the sample

C.

Error that arises from incorrect recording of responses

D.

Error minimized by taking a larger sample
Correct Answer: C

Solution:

Non-sampling errors include errors in data acquisition, such as incorrect recording of responses.

A.

Personal Interviews

B.

Mailing Questionnaire

C.

Telephone Interviews

D.

Exit Polls
Correct Answer: B

Solution:

Mailing questionnaires often result in low response rates due to non-return or loss of the questionnaire.

A.

It includes every element of the population.

B.

It is a type of non-random sampling.

C.

It only surveys a small group of people.

D.

It is conducted every five years.
Correct Answer: A

Solution:

A Census includes every element of the population, providing complete data.

A.

High cost

B.

Inability to reach remote areas

C.

Low response rate

D.

Influence on respondents
Correct Answer: C

Solution:

Mailing surveys often suffer from low response rates due to factors like non-return of questionnaires.

A.

High cost

B.

Limited reach to remote areas

C.

Low response rates

D.

Influence on respondents
Correct Answer: C

Solution:

Mailing questionnaires often result in low response rates due to factors like non-return of questionnaires or loss in mail.

A.

Increasing the sample size.

B.

Conducting a pilot survey.

C.

Using leading questions.

D.

Selecting samples based on convenience.
Correct Answer: A

Solution:

Sampling errors can be minimized by increasing the sample size, which provides a more accurate estimate of the population parameter.

A.

Every individual has an equal chance of being selected.

B.

Selection is based on convenience or judgment.

C.

It is also known as the lottery method.

D.

It is always free from bias.
Correct Answer: B

Solution:

Non-random sampling involves selecting samples based on convenience or judgment, rather than giving each individual an equal chance of being selected.

A.

It is less time-consuming and less expensive.

B.

It provides more detailed information.

C.

It eliminates all types of errors.

D.

It covers the entire population.
Correct Answer: A

Solution:

Sample surveys are typically less time-consuming and less expensive than a census because they involve collecting data from a smaller subset of the population.

A.

It covers the entire population.

B.

It is less expensive and time-consuming.

C.

It provides more detailed information.

D.

It eliminates all types of errors.
Correct Answer: B

Solution:

Sample surveys are preferred because they are less expensive and time-consuming compared to a census.

A.

It provides more detailed information at a lower cost.

B.

It eliminates all forms of data collection errors.

C.

It ensures that every individual in the population is surveyed.

D.

It guarantees a higher accuracy than a census.
Correct Answer: A

Solution:

A sample survey is generally smaller than the population and is capable of providing reasonably accurate information about the population at a much lower cost and shorter time.

A.

Random sampling using a lottery method.

B.

Convenience sampling by selecting easily accessible individuals.

C.

Systematic sampling with a fixed interval.

D.

Stratified sampling based on demographic characteristics.
Correct Answer: B

Solution:

Convenience sampling can introduce sampling bias because it relies on selecting individuals who are easily accessible, which may not represent the entire population.

A.

Sampling error

B.

Non-response error

C.

Data acquisition error

D.

Measurement error
Correct Answer: B

Solution:

Non-response error occurs when selected respondents do not provide information, leading to potential bias in the survey results.

A.

National Sample Survey (NSS)

B.

Central Statistics Office (CSO)

C.

Registrar General of India (RGI)

D.

Labour Bureau
Correct Answer: C

Solution:

The Registrar General of India is responsible for conducting the Census of India.

A.

It provides less accurate data.

B.

It requires a smaller team of enumerators.

C.

It is more time-consuming and expensive.

D.

It does not cover every individual in the population.
Correct Answer: C

Solution:

A Census survey is more time-consuming and expensive because it involves collecting data from every individual in the population.

A.

Sampling bias

B.

Difference between sample estimate and population parameter

C.

Random selection of samples

D.

Increase in sample size reduces error
Correct Answer: A

Solution:

Non-sampling errors include sampling bias, which occurs when the sampling plan excludes certain members of the target population.

A.

National Sample Survey (NSS)

B.

Central Statistics Office (CSO)

C.

Registrar General of India (RGI)

D.

Labour Bureau
Correct Answer: C

Solution:

The Registrar General of India (RGI) is responsible for conducting the Census of India, which provides comprehensive demographic data.

A.

It includes every element of the population.

B.

It is less expensive than sample surveys.

C.

It is conducted randomly.

D.

It is always more accurate than sample surveys.
Correct Answer: A

Solution:

A Census survey includes every element of the population, providing complete data.

A.

Census of India

B.

National Sample Survey

C.

Personal Interviews

D.

Central Statistics Office
Correct Answer: C

Solution:

Primary data is collected directly from the source through methods like personal interviews.

A.

Personal interviews

B.

Mailing questionnaires

C.

Telephone interviews

D.

Online surveys
Correct Answer: D

Solution:

Online surveys are cost-effective and can reach a large and geographically dispersed population quickly, unlike personal interviews or telephone interviews which may be limited by geographical constraints.

A.

They can be minimized by increasing the sample size.

B.

They are less serious than sampling errors.

C.

They include errors in data acquisition.

D.

They do not occur in Census data.
Correct Answer: C

Solution:

Non-sampling errors include errors in data acquisition, such as recording incorrect responses, and are not minimized by increasing sample size.

A.

They are less expensive.

B.

They can be conducted quickly.

C.

They may influence respondents.

D.

They provide no opportunity for clarification.
Correct Answer: C

Solution:

Personal interviews may influence respondents due to the presence of the interviewer.

A.

It includes every element of the population.

B.

It is larger than the population.

C.

It accurately reflects the characteristics of the population.

D.

It is always selected using non-random methods.
Correct Answer: C

Solution:

A representative sample accurately reflects the characteristics of the population, allowing for reliable inferences.

A.

To finalize the research hypothesis.

B.

To pre-test the questionnaire and identify potential issues.

C.

To collect the final data for analysis.

D.

To reduce the sample size.
Correct Answer: B

Solution:

A pilot survey is conducted to pre-test the questionnaire and identify any shortcomings or issues before the main survey.

A.

Census of India

B.

National Sample Survey (NSS)

C.

Central Statistics Office (CSO)

D.

Registrar General of India (RGI)
Correct Answer: B

Solution:

The National Sample Survey (NSS) conducts nationwide surveys on socio-economic issues in India.

A.

Personal Interviews

B.

Mailing Surveys

C.

Telephone Interviews

D.

Online Surveys
Correct Answer: A

Solution:

Personal interviews involve face-to-face interaction, allowing the interviewer to explain the study and answer any queries.

A.

It provides more detailed information.

B.

It is less expensive and time-consuming.

C.

It eliminates all types of errors.

D.

It ensures complete accuracy.
Correct Answer: B

Solution:

A sample survey is generally less expensive and time-consuming than a census because it involves collecting data from a smaller group rather than the entire population.

A.

To finalize the sample size.

B.

To identify and rectify any shortcomings in the questionnaire.

C.

To collect the final data for analysis.

D.

To ensure all questions are multiple-choice.
Correct Answer: B

Solution:

Pre-testing the questionnaire in a pilot survey helps identify and rectify any shortcomings, ensuring clarity and effectiveness before the actual survey.

A.

To reduce the cost of the main survey

B.

To test the clarity and effectiveness of the questionnaire

C.

To gather data for final analysis

D.

To increase the sample size
Correct Answer: B

Solution:

A pilot survey is conducted to pre-test the questionnaire, identify any issues, and ensure that the questions are clear and effective before the main survey is conducted.

A.

It is always larger than the population

B.

It provides accurate information at a lower cost

C.

It includes every individual in the population

D.

It is selected based on convenience
Correct Answer: B

Solution:

A good sample is smaller than the population and provides reasonably accurate information at a lower cost and shorter time.

A.

Lottery method

B.

Convenience sampling

C.

Random number table

D.

Exit polls
Correct Answer: B

Solution:

Convenience sampling is a non-random method where samples are selected based on ease of access.

A.

To understand and analyze economic problems

B.

To increase the literacy rate

C.

To predict weather patterns

D.

To improve agricultural techniques
Correct Answer: A

Solution:

The main purpose of collecting data in economics is to understand, explain, and analyze economic problems and the causes behind them.

A.

They allow for clarification of questions.

B.

They are the least expensive method.

C.

They are time-consuming and expensive.

D.

They provide the lowest response rate.
Correct Answer: C

Solution:

Personal interviews are time-consuming and expensive as they require trained interviewers and longer time to complete the survey.

A.

Data collected through a national census

B.

Data obtained from a published research paper

C.

Data gathered from a government statistical report

D.

Data retrieved from an online database
Correct Answer: A

Solution:

Primary data is based on firsthand information, such as data collected directly through a national census.

A.

High cost

B.

Low response rate

C.

Influence of interviewer

D.

Limited geographical reach
Correct Answer: B

Solution:

Mail surveys often suffer from low response rates due to non-return of questionnaires or incomplete responses.

A.

All farms in Punjab

B.

A random selection of farms across different districts in Punjab

C.

Farms in one district of Punjab

D.

Farms owned by a single agricultural company
Correct Answer: B

Solution:

A random selection of farms across different districts will provide a representative sample of the entire region.

A.

It is less expensive

B.

It ensures every individual has an equal chance of being selected

C.

It requires fewer enumerators

D.

It provides more detailed information
Correct Answer: B

Solution:

Random sampling ensures that every individual in the population has an equal chance of being selected, which helps in obtaining a representative sample.

A.

All units of the population have an equal chance of being selected

B.

Selection is based on the researcher's judgment

C.

Samples are selected based on convenience

D.

Samples are selected based on quota
Correct Answer: A

Solution:

In random sampling, every individual or unit has an equal chance of being selected, which helps to reduce bias and ensure the representativeness of the sample.

A.

Sampling bias

B.

Non-response error

C.

Error in data acquisition

D.

All of the above
Correct Answer: D

Solution:

Non-sampling errors include sampling bias, non-response errors, and errors in data acquisition, which can occur regardless of sample size.

A.

It provides more detailed information than a census.

B.

It is less expensive and time-consuming than a census.

C.

It eliminates all types of errors.

D.

It requires more enumerators than a census.
Correct Answer: B

Solution:

A sample survey is often chosen over a census because it is less expensive and requires less time to conduct, while still providing reasonably accurate estimates.

A.

An error due to incorrect data recording

B.

An error due to the difference between sample estimate and population parameter

C.

An error caused by non-response

D.

An error due to biased question framing
Correct Answer: B

Solution:

A sampling error is the difference between the sample estimate and the actual value of the population parameter.

A.

Selecting a smaller sample size.

B.

Recording incorrect responses due to transcription errors.

C.

Using random sampling methods.

D.

Calculating the sample mean incorrectly.
Correct Answer: B

Solution:

Non-sampling errors include errors in data acquisition, such as recording incorrect responses due to transcription errors.

A.

Sampling bias

B.

Non-response errors

C.

Errors in data acquisition

D.

Random selection of samples
Correct Answer: D

Solution:

Random selection of samples is a characteristic of random sampling and does not contribute to non-sampling errors.

A.

It allows for the selection of samples based on convenience.

B.

It ensures every individual has an equal chance of being selected.

C.

It is less expensive than other methods.

D.

It guarantees a higher response rate.
Correct Answer: B

Solution:

Random sampling ensures that every individual in the population has an equal chance of being selected, which helps in obtaining a representative sample.

A.

It is smaller than the population.

B.

It provides accurate information about the population.

C.

It includes every individual in the population.

D.

It is selected randomly.
Correct Answer: C

Solution:

A good sample is smaller than the population and is capable of providing accurate information. It does not include every individual, which would make it a census.

A.

Census of India

B.

National Sample Survey (NSS)

C.

Central Statistics Office (CSO)

D.

Labour Bureau
Correct Answer: B

Solution:

The National Sample Survey (NSS) conducts nationwide surveys on socio-economic issues.

True or False

Correct Answer: False

Solution:

Non-sampling errors cannot be completely eliminated by taking a larger sample. They can occur due to various factors like data acquisition errors or non-response.

Correct Answer: True

Solution:

The Census of India has been conducted every ten years since 1881, collecting comprehensive demographic data.

Correct Answer: False

Solution:

While sample surveys can provide reasonably reliable and accurate information, a census covers every individual and provides the most complete data.

Correct Answer: True

Solution:

The NSS conducts nation-wide surveys on socio-economic issues in continuous successive rounds.

Correct Answer: False

Solution:

Mail surveys are generally less expensive compared to personal interviews.

Correct Answer: True

Solution:

Data collection aims to provide evidence for reaching a sound and clear solution to a problem.

Correct Answer: True

Solution:

Sample surveys are preferred because they provide reliable information at a lower cost and in a shorter time compared to a census.

Correct Answer: False

Solution:

In non-random sampling, not all units have an equal chance of being selected; selection is based on judgment, convenience, or quota.

Correct Answer: True

Solution:

In random sampling, every individual in the population has an equal chance of being selected, ensuring unbiased representation.

Correct Answer: True

Solution:

A pilot survey helps in pre-testing the questionnaire to identify any shortcomings before the main survey.

Correct Answer: True

Solution:

Sample surveys are preferred because they provide reliable information at a lower cost and in a shorter time.

Correct Answer: False

Solution:

In non-random sampling, not all units have an equal chance of being selected, as selection is based on judgment, purpose, or convenience.

Correct Answer: True

Solution:

The Census of India is indeed conducted every ten years, providing comprehensive demographic data.

Correct Answer: True

Solution:

The NSS conducts nationwide surveys in successive rounds to provide data on literacy, employment, and other socio-economic factors.

Correct Answer: False

Solution:

Non-sampling errors cannot be minimized by increasing the sample size. They arise from issues like data acquisition errors and non-response.

Correct Answer: True

Solution:

Primary data is obtained directly from the source through methods like surveys, interviews, and experiments.

Correct Answer: True

Solution:

Random sampling ensures that every individual has an equal chance of being selected.

Correct Answer: False

Solution:

Exit polls are not always accurate in predicting election results due to sampling errors and other biases.

Correct Answer: True

Solution:

Data collection aims to show evidence for reaching a sound and clear solution to a problem, as mentioned in the excerpts.

Correct Answer: False

Solution:

Non-sampling errors are not reduced by increasing the sample size and can occur due to bias, data acquisition errors, and non-response.

Correct Answer: False

Solution:

The Census of India is conducted every ten years, not five.

Correct Answer: True

Solution:

The Census of India is conducted every ten years, as stated in the excerpts.

Correct Answer: True

Solution:

Sample surveys are preferred because they provide reliable information at a lower cost and shorter time than a census.

Correct Answer: False

Solution:

Personal interviews are often the most expensive method of data collection due to the need for trained interviewers and the time required.

Correct Answer: True

Solution:

The Census of India is indeed conducted every ten years and collects comprehensive demographic data.

Correct Answer: False

Solution:

While increasing the sample size can reduce sampling errors, it cannot completely eliminate them.

Correct Answer: True

Solution:

Mailing questionnaires can effectively reach respondents in remote areas where personal or telephone interviews may not be feasible.

Correct Answer: False

Solution:

Personal interviews are expensive as they require trained interviewers and take longer to complete.

Correct Answer: False

Solution:

Primary data is collected directly from first-hand sources, not from secondary sources.

Correct Answer: False

Solution:

Primary data is collected firsthand through surveys and direct observations, not from secondary sources.

Correct Answer: False

Solution:

Mailing questionnaires is less expensive compared to personal interviews, as it allows access to remote areas and does not involve direct interaction.

Correct Answer: True

Solution:

A pilot survey helps in pre-testing the questionnaire to identify any issues before the main survey.

Correct Answer: True

Solution:

Random sampling ensures that every individual in the population has an equal chance of being selected.

Correct Answer: True

Solution:

In random sampling, each member of the population has an equal probability of being included in the sample.

Correct Answer: False

Solution:

Non-sampling errors are difficult to minimize even by taking a large sample.

Correct Answer: False

Solution:

Exit polls do not always predict election results accurately, as mentioned in the excerpts.