B- For all persons
[Question 1 to 7 were asked of all persons]
4. How old was [the respondent] at his or her last birthday?
Enter age in completed years ("00" for children less than one year). Example: Name is 37. [First digit in the first box and the second digit in the second box]
Age _ _
Section B: For all Persons
Begin by saying, "I would like information on ALL people who stayed at this household on the census night. This information is on the names of the persons, their relationship to head of household, their age and sex, survivorship of their parents etc. It is important that you give me as accurate information as possible about each person".
Q4 Age - Alternatively Ask "When was (the respondent) born?"
Entries should be made in completed years as follows:
- "00" for children less than a year;
- Actual ages for those age 1-97 years;
- "98" for those age 98 years and over;
Age is one of the most important questions as almost all analysis of data depends on respondent's age, for example, fertility rates calculated by age of woman etc. Be careful not to round up ages to the next birthday; the age of a child who is four years and eleven months should be recorded as 04 and not 05.
For calculation of ages, the following could be useful:
- If day, month and year of birth are given, and then when the birthday is after the census night, the age should be 2011 minus year of birth; where the birthday is before the census night, the age should be 2012 minus year of birth.
- To assist you with verifications of these calculations, an age determination table is shown in Appendix 1. In the table you have the decade on the left hand column and the last digit in the year of birth on the top row. Two rows of ages are then presented. The top row indicates the age when the birthday is before the census night, while the bottom row gives the age when the birthday is after the census night.
If year of birth is given and respondent cannot recall the month:
- Subtract the year from 2012 to obtain age.
- If the age is not known, probe to try to estimate age. This is time consuming and sometimes tedious, but it is important to take time to try to get the best possible information.
There are several ways that can be used to probe for age:
- You may ask about the year, month and day when the person was born.
- You may probe for age at last completed birthday, i.e. you may ask whether their birthday has passed in the current year, and when that was.
- In the case of a woman respondent, you may ask how old she was when she got married or had her first child, then try to estimate how long ago she got married or had her first child.
- It might be possible to relate the age of the person to that of someone else in the household whose age is reliably known.
[pg. 24]
If probing does not help, you may have to estimate the age as a last resort when all other efforts have failed. Avoid the use of IDs as a means of estimating a person's age because, more often than not, if a person does not know when s/he was born, the age on the ID is also wrong.