chpt 11

• Sampling error


  Error in a survey due to the sampling selection or sample size
• Non-sampling error


  All errors in a survey except those due to the sampling selection or sample size
• Types of non-sampling error

  • Nonresponse error
  • Data-gathering errors
  • Data-handling errors
  • Data analysis errors
  • Interpretation errors
  • Errors in problem definition
  • Errors in question wording
• Non-sampling error

  • Cannot be measured by a formula, so controls need to be imposed on the data collection process to minimize the effects
• Possible errors in field data collection


  • Fieldworker errors
  • Respondent errors
• Fieldworker error


  Errors committed by the individuals who administer questionnaires, typically interviewers
• Respondent error


  Errors committed on the part of the respondent
• Types of fieldworker error, Intentional errors:

  • cheating
  • falsehoods
  • leading respondents
• Types of respondent errors

  • Intentional errors (nonresponse, falsehoods, speeding)
  • Unintentional errors (misunderstandings, guessing, attention loss, distractions, fatigue)
• Intentional fieldworker error


  Errors committed when a data collection person willfully violates the data collection requirements set forth by the researcher
• Unintentional fieldworker error


  Errors committed when an interviewer believes he or she is performing correctly
• Intentional respondent error


  Errors committed when there are respondents that willfully misrepresent themselves in surveys
• Unintentional respondent error


  Errors committed when a respondent gives a response that is not valid but that he or she believes is the truth
• Non-sampling error can lead to wrong results and poor decisions by management that can negatively affect the business
• Field data collection quality controls

  • Control of intentional fieldworker error (supervision, validation)
  • Control of unintentional fieldworker error (orientation sessions, role-playing, methods to reduce fatigue)
  • Control of intentional respondent error (anonymity, confidentiality, incentives, validation checks, third-person technique)
  • Control of unintentional respondent error (well-drafted questionnaire instructions, reversals of scale endpoints, prompters)
• Nonresponse


  Failure on the part of a prospective respondent to take part in a survey or to answer specific questions on the survey
• Types of nonresponse


  • Refusal (prospective respondent declines to participate)
  • Break-off (respondent stops participating after answering some questions)
  • Item omission (respondent does not answer a particular question)
• Response rate


  Number of completed interviews divided by the number of eligible units in the sample
• Types of fieldworker error, unintentional errors:

  • Interviewer characteristics
  • Misunderstanding
  • Fatigue
• Type of nonresponse error: Refusal 


  prospective respondent declines to participate
• Type of nonresponse error: Break-off


  Respondent stops participating after answering some questions
• Type of nonresponse error: item omission


  Respondent does not answer a particular question
• Control of unintentional fieldworker error


  Orientation sessions, role-playing, methods to reduce fatigue
• Control of intentional respondent error


  Anonymity, confidentiality, incentives, validation checks, third-person technique
• Control of unintentional respondent error


  Well-drafted questionnaire instructions, reversals of scale endpoints, prompters
• Unintentional respondent errors 


  Misunderstandings, guessing, attention loss, distractions, fatigue