Contact informationBack
| Date of survey | : | May 7 to 15 and June 2 to 13, 2008 | |
| Survey method | : | Random telephone survey conducted by real interviewers | |
| Target population | : | Cantonese-speaking population of Hong Kong who fulfilled either one of the following criteria: 1) parents aged 18-year or above with at least one child aged 17-year or below; 2) young adults aged between 18 and 34-year with no children; and 3) children aged between 9 and 17-year. | |
| 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.
|
|
| Sample size | : | 1,516 successful cases, with 506 parents, 506 young adults and 504 children | |
| Overall Response rate | : | Parents: 77.8% |
|
| Std. sampling error | : | Less than 2.2 percentage points. In other words, the sampling error for all percentages was less than plus/minus 4.5percentage points at 95% confidence level. |
| Table 1 Breakdown of contact information of the survey (Parents) |
|
Frequency |
Percentage |
Respondents' ineligibility confirmed |
10,547 |
50.7% |
Fax/ data line |
943 |
4.5% |
Invalid number |
6,242 |
30.0% |
Call-forwarding/ mobile/ pager number |
160 |
0.8% |
Non-residential number |
1,104 |
5.3% |
Special technological difficulties |
99 |
0.5% |
No eligible respondents |
1,999 |
9.6% |
|
|
|
Respondents' ineligibility not confirmed |
5,263 |
25.3% |
Line busy |
420 |
2.0% |
No answer |
3,614 |
17.4% |
Answering device |
107 |
0.5% |
Call-blocking |
77 |
0.4% |
Language problem |
360 |
1.7% |
Interview terminated before the screening question |
523 |
2.5% |
Others |
162 |
0.8% |
|
|
|
Respondents' eligibility confirmed, but failed to complete the interview |
4,468 |
21.5% |
Household-level refusal |
13 |
0.1% |
Known respondent refusal |
8 |
0.0% |
|
Appointment date beyond the end of the fieldwork period |
4,112 |
19.8% |
|
Partial interview |
12 |
0.1% |
|
Miscellaneous |
323 |
1.6% |
|
|
|
Successful cases |
506 |
2.4% |
|
|
|
Total |
20,784 |
100.0% |
| Table 2 Calculation of effective response rate (Parents) |
|
^ Figure obtained by prorata
| Table 3 Breakdown of contact information of the survey (Young adults) |
Frequency |
Percentage |
|
| Respondents' ineligibility confirmed | 10,549 |
50.8% |
| Fax/ data line | 943 |
4.5% |
Invalid number |
6,242 |
30.0% |
Call-forwarding/ mobile/ pager number |
160 |
0.8% |
Non-residential number |
1,104 |
5.3% |
Special technological difficulties |
99 |
0.5% |
| No eligible respondents | 2,001 |
9.6% |
|
|
|
| Respondents' ineligibility not confirmed | 5,261 |
25.3% |
| Line busy | 420 |
2.0% |
No answer |
3,613 |
17.4% |
Answering device |
107 |
0.5% |
Call-blocking |
77 |
0.4% |
Language problem |
360 |
1.7% |
| Interview terminated before the screening question | 522 |
2.5% |
| Others | 162 |
0.8% |
|
|
|
| Respondents' eligibility confirmed, but failed to complete the interview | 4,468 |
21.5% |
| Household-level refusal | 13 |
0.1% |
| Known respondent refusal | 8 |
0.0% |
| Appointment date beyond the end of the fieldwork period | 4,112 |
19.8% |
| Partial interview | 12 |
0.1% |
| Miscellaneous | 323 |
1.6% |
|
|
|
| Successful cases | 506 |
2.4% |
|
|
|
| Total | 20,784 |
100.0% |
| Table 4 Calculation of effective response rate (Young adults) |
|
^ Figure obtained by prorata
| Table 5 Breakdown of contact information of the survey (Children) |
Frequency |
Percentage |
|
| Respondents' ineligibility confirmed | 16,951 |
53.7% |
| Fax/ data line | 1,310 |
4.2% |
Invalid number |
8,644 |
27.4% |
Call-forwarding/ mobile/ pager number |
222 |
0.7% |
Non-residential number |
1,559 |
4.9% |
Special technological difficulties |
155 |
0.5% |
| No eligible respondents | 5,061 |
16.0% |
|
|
|
| Respondents' ineligibility not confirmed | 7,550 |
23.9% |
| Line busy | 589 |
1.9% |
No answer |
5,303 |
16.8% |
Answering device |
134 |
0.4% |
Call-blocking |
110 |
0.3% |
Language problem |
462 |
1.5% |
| Interview terminated before the screening question | 683 |
2.2% |
| Others | 269 |
0.9% |
|
|
|
| Respondents' eligibility confirmed, but failed to complete the interview | 6,540 |
20.7% |
| Household-level refusal | 27 |
0.1% |
| Known respondent refusal | 22 |
0.1% |
| Appointment date beyond the end of the fieldwork period | 5,898 |
18.7% |
| Partial interview | 14 |
0.0% |
| Miscellaneous | 579 |
1.8% |
|
|
|
| Successful cases | 504 |
1.6% |
|
|
|
| Total | 31,545 |
100.0% |
| Table 6 Calculation of effective response rate (Children) |
|
^ Figure obtained by prorata
