Q.Distinguish between the census method and the sample method of data collection, and state one situation in which each would be the appropriate choice.

The census and sample methods differ mainly in how much of the population is actually studied, which in turn affects their cost, time, and accuracy trade-offs.

Census Method (complete enumeration): every single unit of the population is individually observed or measured; no unit is omitted. It is costly and time-consuming, but leaves no sampling error, and is legally mandated for national counts such as India's Population Census.

Sample Method: only a carefully selected part of the population is studied, and the results are generalised to the whole population using statistical inference. It is faster and cheaper, and is the only practical choice when the population is very large or when testing would destroy the units tested (e.g., checking the bursting strength of pressure cookers).

When each is appropriate: a census suits a small, easily accessible population, or where the law requires every unit to be covered (e.g., a national population count). A sample suits a large or widely spread population, or where a quick, low-cost estimate with a known margin of error is acceptable (e.g., a company's customer-satisfaction survey).

Assuming the census is always 'more accurate' — a census has no sampling error but can suffer badly from non-sampling error at scale (rushed, poorly supervised data collection across millions of units), so a well-designed sample survey can sometimes be more reliable in practice.