Q.A government agency wants to collect data on annual income directly from 5,000 households spread across many remote villages, using trained field staff who visit each household in person and fill in a prescribed form based on the households' answers. Identify the method of primary data collection being used, and state one advantage and one disadvantage of this method compared to a mailed questionnaire.

Trained staff visiting households in person and filling a prescribed form on the spot, based on the respondent's answers, is the defining description of the Schedule Method. …

Step 1 — Match the description to a method. The scenario describes trained field staff (enumerators) physically visiting each of 5,000 households and filling in a prescribed schedule themselves, based on the households' spoken answers — this is precisely the Schedule Method, distinct from a mailed questionnaire (where the respondent fills the form unaided and returns it by post) and distinct from Direct Personal Investigation (where the investigator, not a separately trained enumerator network, does the interviewing, and which does not scale to 5,000 households across remote villages as easily).

Step 2 — State an advantage over a mailed questionnaire. Because an enumerator is physically present, they can explain a confusing question, ensure every item is answered, and reduce non-response — a mailed questionnaire sent to remote villages would likely suffer heavy non-response and misunderstood questions, especially where literacy levels vary. …

Confusing the Schedule Method with the Mailed Questionnaire Method is common, since both use a prepared list of questions — the distinguishing feature is WHO fills in the form: the respondent alone (ques …