Contact information返回

  Date of survey : 18/3-1/4/2010
  Survey method : Telephone survey conducted by telephone interviewers
  Target population : local working population aged 18 to 65 with a minimum monthly personal income of HK$5,000 and being covered by an MPF scheme
  Sampling method : The contacts were successfully established with a target household, one target respondent was selected. If more than one subject had been available, selection was made using the "next birthday rule" which selected the person who had his/her birthday next from all those present.
  Sample size : 1,001 successful cases
  Effective Response rate : 65.2%
  Std. sampling error : Less than 1.6%

Table 1 Calculation of effective response rate

   Effective Response rate
= [ Successful cases / (Successful cases + Partial interview + Refusal cases by eligible respondents + Refusal cases by prorated-eligible respondents) ]
= [ 1,001 / 1,001 + 65 + 27+ 698[(1,001 + 65 + 27) / (1,001 + 65 + 27 + 636)]* ]
= 65.2%
*Figure obtained by prorata

Table 2 Breakdown of contact information of the survey

 

Frequency

Percentage

Respondents' ineligibility confirmed

12,102

42.3%

Fax/ data line

1,084

3.8%

Invalid number

9,168

32.0%

Call-forwarding/ mobile/ pager number

140

0.5%

Non-residential number

1,018

3.6%

Special technological difficulties

56

0.2%

No eligible respondents

636

2.2%

 

 

 

Respondents' eligibility not confirmed

6,848

23.9%

Line busy

308

1.1%

No answer

5,039

17.6%

Answering device

146

0.5%

Call-blocking

142

0.5%

Language problem

458

1.6%

Interview terminated before the screening question

698

2.4%

Others

57

0.2%

 

 

 

Respondents' eligibility confirmed, but failed to complete the interview

8,692

30.3%

Household-level refusal

10

0.0%

Known respondent refusal

17

0.1%

Appointment date beyond the end of the fieldwork period

8,478

29.6%

Partial interview

65

0.2%

Miscellaneous

122

0.4%

 

 

 

Successful cases

1,001

3.5%

 

 

 

Total

28,643

100.0%