Research DesignBack


 

The target population of this survey was Macau citizens aged 18 or above. When telephone contact was successfully established with a target household, one person aged 18 or above 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.

 
 

Telephone interviews were conducted during the period of 18 to 28 November 2005. A total of 1,005 Macau citizens aged 18 or above were successfully interviewed. The overall response rate of this survey was 50.6% (Table 2), and the standard sampling error for percentages based on this sample was less than 1.6 percentage points. In other words, the sampling error for all percentages was less than plus/minus 3.2 percentage points at 95% confidence level.


Table 1 - Breakdown of contact information of the survey
   Frequency  Percentage
  Respondents' ineligibility confirmed  751   21.0 
  Fax/ data line  42   1.2 
  Invalid number  580   16.2 
  Call-forwarding/ mobile/ pager number  15   0.4 
  Non-residential number  20   0.6 
  Special technological difficulties  12   0.3 
  No eligible respondents  82   2.3 
 
  Respondents' eligibility not confirmed  1,724   48.3 
  Line busy  81   2.3 
  No answer  536   15.0 
  Answering device  5   0.1 
  Call-blocking  3   0.1 
  Language problem  68   1.9 
  Interview terminated before the screening question  960   26.9 
  Others  71   2.0 
 
  Respondents' eligibility confirmed, but failed to complete the interview  90   2.5 
  Household-level refusal  6   0.2 
  Known respondent refusal  8   0.2 
  Appointment date beyond the fieldwork period  9   0.3 
  Partial interview  7   0.2 
  Miscellaneous  60   1.7 
 
  Successful cases  1,005   28.2 
 
  Total  3,570   100.0 

Table 2 - Calculation of overall response rate

   Overall response rate
= [ Successful cases / (Successful cases + Refusal cases* + Incomplete cases^) ]
= [ 1,005 / ( 1,005 + 932 + 49 ) ]
= 50.6%
* Including "partial interview" and "interview terminated before the screening question"
^ Including "household-level refusal" and "known respondent refusal"