Under this method the enumerators are appointed in different parts of the area of the investigation and they contact with the informants, get replies to the questionnaires and fill them.
Merits :
-Information can be collected even fromthe illeterate persons.
-It is economical in terms of money and labour.
-There are less chances of non-response.
Demerits :
-It required trained enumerators.
-The personal bias of the enumerators may lead to fale conclusions.