Contact InformationBack


  Date of survey : 5 - 14 May, 2008
  Survey method : Telephone survey with interviewers
  Target population : Hong Kong working population 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 : 1,005 successful cases
  Effective Response rate : 76.9%
  Std. sampling error : Less than 1.6%

Table 1 Breakdown of contact information of the survey 
　 Frequency Percentage
Respondents' ineligibility confirmed 4,001 34.8%
Fax/ data line 331 2.9%
Invalid number 2,374 20.6%
Call-forwarding/ mobile/ pager number 150 1.3%
Non-residential number 447 3.9%
Special technological difficulties 24 0.2%
No eligible respondents 675 5.9%
　 　 　
Respondents' eligibility not confirmed 3,541 30.8%
Line busy 276 2.4%
No answer 2,470 21.5%
Answering device 46 0.4%
Call-blocking 33 0.3%
Language problem 182 1.6%
Interview terminated before the screening question 443 3.8%
Others 91 0.8%
  　 　
Respondents' eligibility confirmed, but failed to complete the interview 2,965 25.8%
Household-level refusal 6 0.1%
Known respondent refusal 9 0.1%
Appointment date beyond the end of the fieldwork period 2,461 21.4%
Partial interview 19 0.2%
Miscellaneous 470 4.1%
  　 　
Successful cases 1,005 8.7%
  　 　
Total 11,512 100.0%

Table 2 Calculation of effective response rate

Effective Response rate
= Successful cases / (Successful cases + Incomplete cases + Refusal cases + Estimated refusal cases of eligible respondents*)
= 1,005 / 1,005 + 19 + 6 + 9 + 443[(1,005 + 19 + 6 + 9) / (1,005 + 19 + 6 + 9 + 675)]*
= 76.9%

*Figure obtained by prorata