Question #4: Completed age
a. How to ask the question:
What is the person's age, in years completed?
The information obtained for each person is the number of years completed at the last birthday and not the number to be completed at the next birthday.
Taking into account the importance of this topic, all possible effort should be made in order to obtain the age in the most exact manner possible. It should be remembered that persons, when declaring their age, tend to raise the number in some cases, and to lower the number in other cases. It is also frequent that persons declare, because of ignorance or other reasons, the age in numbers ending in zero or five (20, 30, 40, or 25, 35, 55, etc.). In these cases, it is convenient to request the year of birth as a control. If there is an inconsistency between the two pieces of information, it should be pointed out to the informant and an attempt should be made to obtain the correct information. If a person claims to not know their age, indirect questions should be asked to deduce the age; for example: if the person is married and has children, the age of the oldest child and the age of the person at the time of the birth of the child can be asked. As a last resort, the age should be estimated based on whichever resources are available, such as relating the age to a national or international event such as the beginning of the century, the Earthquake of Managua, the Second World War, etc. Only if the informant does not know the age of a household member and there is no other way to confirm the information is this fact recorded on the census form.
[p. 49]
b. How to record the information:
The following is written above the line located before the word "Years":
1) For those age 1 year or older, the number of years completed;
2) For those younger than 1 year, the digits "00";
3) The word "Unknown" is recorded for those persons whose information was impossible to obtain.
c. Examples:
[These instructions refer to a graph of question 4 on the census form]