Contact informationBack
Date of survey | : | 18-29 January, 2008 | |
Survey method | : | Telephone survey with 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 first drawn randomly from the residential telephone directories as "seed numbers", from which another set of numbers was generated using the "plus/minus one/two" method, in order to capture the unlisted numbers. Duplicated numbers were then filtered, and the remaining numbers were mixed in random order to produce the final telephone sample.
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Sample size | : | 505 successful cases | |
Overall Response rate | : | 81.7% | |
Std. sampling error | : | Less than 2.2 percentage points. In other words, the sampling error for all percentages was less than plus/minus 4.4 percentage points at 95% confidence level. |
Table 1 Calculation of effective response rate |
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Table 2 Breakdown of contact information of the survey |
|
Frequency |
Percentage |
Respondents』 ineligibility confirmed |
5,532 |
46.6% |
Fax/ data line |
684 |
5.8% |
Invalid number |
3,499 |
29.5% |
Call-forwarding/ mobile/ pager number |
48 |
0.4% |
Non-residential number |
488 |
4.1% |
Special technological difficulties |
76 |
0.6% |
No eligible respondents |
737 |
6.2% |
Respondents』 eligibility not confirmed |
2,711 |
22.8% |
Line busy |
156 |
1.3% |
No answer |
1,974 |
16.6% |
Answering device |
68 |
0.6% |
Call-blocking |
49 |
0.4% |
Language problem |
158 |
1.3% |
Interview terminated before the screening question |
238 |
2.0% |
Others |
68 |
0.6% |
Respondents』 eligibility confirmed, but failed to complete the interview |
3,119 |
26.3% |
Household-level refusal |
6 |
0.1% |
Known respondent refusal |
3 |
0.0% |
Appointment date beyond the end of the fieldwork period |
2,733 |
23.0% |
Partial interview |
6 |
0.1% |
Miscellaneous |
371 |
3.1% |
Successful cases |
505 |
4.3% |
Total |
11,867 |
100.0% |