Contact informationBack


  Date of survey : 1 - 14 November 3, 2007
  Survey method : Telephone survey with interviewers
  Target population : Hong Kong citizens of age 18 or above.
  Sampling method :
All data were collected by our interviewers using a Computer Assisted Telephone Interview (CATI) system which allowed real-time data capture and consolidation. To ensure data quality, on top of on-site supervision, voice recording, screen capturing and camera surveillance were used to monitor the interviewers' performance.
  Sample size : 1010 successful cases
  Overall Response rate : 67.7%
  Std. sampling error : Less than 1.6%

Table 1 Breakdown of contact information of the survey 
Respondents' ineligibility confirmed 3,406 39.0%
Fax/ data line 424 4.9%
Invalid number 2,473 28.3%
Call-forwarding/ mobile/ pager number 42 0.5%
Non-residential number 340 3.9%
Special technological difficulties 80 0.9%
No eligible respondents 47 0.5%
　 　 　
Respondents' eligibility not confirmed 2,455 28.1%
Line busy 184 2.1%
No answer 1,587 18.2%
Answering device 45 0.5%
Call-blocking 30 0.3%
Language problem 133 1.5%
Interview terminated before the screening question 455 5.2%
Others 21 0.2%
  　 　
Respondents' eligibility confirmed, but failed to complete the interview 1,853 21.2%
Household-level refusal 0 0.0%
Known respondent refusal 5 0.1%
Appointment date beyond the end of the fieldwork period 1,772 20.3%
Partial interview 24 0.3%
Miscellaneous 52 0.6%
  　 　
Successful cases 1,010 11.6%
  　 　
Total 8,724 100.0%

Table 2 Calculation of response rate 

   Overall Response rate
= [ Successful cases / (Successful cases + Incomplete cases* + Refusal cases by eligible respondents^) ]
= [ 1010 / ( 1010 + 479 + 5 ) ]
= 67.6%
* Including "partial interview" and "interview terminated before the screening question" 
^ Including "company-level refusal" and "known respondent refusal"