Systematic sampling is one in which the initial unit of sample is selected at random from the initial stratum of the universe and the other units are selected at a certain space interval from the universe arranged in a systematic order like numerical, alphabetical and geographical order.
(i) This technique of selection is independent of the property of the universe which is under study and so it gives quite a representative sample.
(ii) There is a little chance of bias creeping into the sample.
(iii) It is quite popular in the random draw of prizes and selection of a contesting candidate in a tie position.
(i) The selection may be affected by bias of the drawer if all the chits are not folded identically and are not of identical size, shape and colour.
(ii) It is not suitable for a large sized universe for that it will be very difficult to write down the names or particulars of a large number of units on the chits of paper.
(iii) It consumes lot of time and energy.