Contact information返回
| Date of survey | : | June 18 to 19, 2008 | |
| Survey method | : | Random telephone survey conducted by real interviewers | |
| Target population | : | The target population of this survey was the local working population of age 25 or above who had traveled outside of Hong Kong in the past 2 years. | |
| 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 | : | 558 successful cases | |
| Overall Response rate | : | 67.2% |
|
| Std. sampling error | : | Less than 2.1 percentage points. In other words, the sampling error for all percentages was less than plus/minus 4.2percentage points at 95% confidence level. |
| Table 1 Breakdown of contact information of the survey |
|
Frequency |
Percentage |
Respondents' ineligibility confirmed |
3,925 |
29.2% |
Fax/ data line |
400 |
3.0% |
Invalid number |
2,722 |
20.2% |
Call-forwarding/ mobile/ pager number |
60 |
0.4% |
Non-residential number |
392 |
2.9% |
Special technological difficulties |
37 |
0.3% |
No eligible respondents |
314 |
2.3% |
|
|
|
Respondents' ineligibility not confirmed |
4,240 |
31.5% |
Line busy |
631 |
4.7% |
No answer |
2,902 |
21.6% |
Answering device |
97 |
0.7% |
Call-blocking |
38 |
0.3% |
Language problem |
192 |
1.4% |
Interview terminated before the screening question |
312 |
2.3% |
Others |
68 |
0.5% |
|
|
|
Respondents' eligibility confirmed, but failed to complete the interview |
4,734 |
35.2% |
Household-level refusal |
13 |
0.1% |
Known respondent refusal |
6 |
0.0% |
|
Appointment date beyond the end of the fieldwork period |
4,304 |
32.0% |
|
Partial interview |
46 |
0.3% |
|
Miscellaneous |
365 |
2.7% |
|
|
|
Successful cases |
558 |
4.1% |
|
|
|
Total |
13,457 |
100.0% |
| Table 2 Calculation of effective response rate |
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