The following five points will highlight the advantages of sampling over complete enumeration in statistics.
(i) In any sampling method we consider only a small part of the entire population available and hence it requires less time, money and manpower.
Complete enumerations, on the other hand, of course require all these factors in large quantities and therefore this method is more expensive.
(ii) While adopting sampling technique a few selected and sufficiently trained efficient investigators on that field are engaged who can successfully collect the required information from the large population through a well-designed and quite comprehensive questionnaire prepared earlier following the “cross-checking” method. Naturally, the data so obtained are much dependable for’ the researchers and for other users also. Complete enumeration can never produce such data within that limited time and monetary expenses.
(iii) As far as errors in both the methods are concerned, the sampling technique usually contains sampling errors to a small extent. For the complete enumeration procedure, instead of sampling errors, non-sampling errors are much predominant here and it thus affects the results of the required investigation much significantly and drastically.
(iv) While adopting any sampling technique, the nature and the magnitude of sampling errors are distinctly measurable afterwards with the aid of the ‘probability theory’ and hence all necessary efforts to minimise those errors can easily be taken in advance. Conversely, complete enumeration do not have any such sampling error but the huge non-sampling errors involved there are not at all traceable afterwards and hence numerically not measurable through the ‘probability theory’ and it thus affects the entire investigation procedure quite significantly.
(v) In some practical situations, complete enumeration procedure can never be followed. A suitable example in this respect may be, to examine the quality of tea by a tea-taster in a tea producing company the taster can only enjoy the various samples of tea separately and finally offer his or her own opinion.
Because of the above advantages of sampling over complete enumeration, sampling techniques are much more popular and widely used in different disciplines today. However, for a particular population where the units contained in it are completely different in their own characteristics, the complete enumeration procedure will give us better results.