Table 1: Final status of telephone numbers attempted
Type   Final status of contacts3   Number of case
1   Success   1,064  
2   Partial   187  
3   Language problem   162  
4   Fail to qualify   29  
5   Business number   878  
6   Refusal   408  
7   Not Available   2,995  
8   No Answer   2,859  
9   Busy   255  
10   Fax/Data   578  
11   Invalid   4,011  
    Total   13,426  

Overall Response Rate
= (success) / (success + refusals by targeted respondents + partial)
= 1,064/ (1,064 + 408 + 187)
= 64.1%

2 Contact rate = the number of answered telephone calls divided by the total number of calls attempted, i.e. from Table 1, Sum of (types 1 to 7) / Total = (1,064+187+162+29+878+408+2995) /13,426=42.6 %.
 3 'Drop-out': eligible respondents who initially accepted the interview but failed to complete the interview due to some reasons. 'Refusal': eligible respondents who refused the interview. 'Language problems': eligible respondents who were not able to speak clearly in any of the 3 languages. 'Not available': eligible respondents were busy at the time of telephone contact. 'Invalid': not a valid telephone line.