Contact InformationBack


  Date of survey : 28 - 31 July,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 : 1,003 successful cases
  Effective Response rate : 75.9%
  Std. sampling error : Less than 1.6%

Table 1 Breakdown of contact information of the survey 
　 Frequency Percentage

Respondents' ineligibility confirmed

1,153

16.3

Fax/ data line

 75 1.1

Invalid number

 609 8.6

Call-forwarding/ mobile/ pager number

 75 1.1

Non-residential number

 82 1.2

Special technological difficulties

 15 0.2

No eligible respondents

 297 4.2
　 　 　

Respondents' eligibility not confirmed

2,058

29.1

Line busy

 87 1.2

No answer

 1,338 18.9

Answering device

 20 0.3

Call-blocking

 11 0.2

Language problem

 84 1.2

Interview terminated before the screening question

 382 5.4

Others

 136 1.9

 

 　 　

Respondents' eligibility confirmed, but failed to complete the interview

2,861

40.4

Household-level refusal

 3 0.0

Known respondent refusal

 3 0.0

Appointment date beyond the end of the fieldwork period

 2522 35.6

Partial interview

 17 0.2

Miscellaneous

 316 4.5

 

 　 　

Successful cases

1,003

14.2

 

 　 　

Total

7,075

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*)
= 1,003 / 1,003 + 17 + 3 + 3 + 382[(1,003 + 17 + 3 + 3) / (1,003 + 17 + 3 + 3 + 297)]*
= 75.9%

*Figure obtained by prorata