the knowledge or experiences necessary to answer the research question. Therefore, the researcher will stop administering the questionnaire to females after he interviews the 15th female respondent, that is, when the" of 15 females is filled. Therefore, he requires the first item to be selected at the random as the starting point and subsequently he can choose every kth item for evaluation against specifications. It is often noticed that companies frequently select certain preferred cities during test marketing their products. Example: We want to estimate the total income of adults living in a given street. If the visitor is a squash player, then he is requested to refer the names of at least 3 other players known to him. The invigilator is asked to select the required number of units of the sample of his own accord and examine them to get the desired information as quickly as possible.
(ii bias: It is very much influenced by the bias and personal convenience of the investigator. A smaller sample can be drawn from the known to have the elements with the same value whereas sample can be drawn in much higher proportion from another stratum where the values are known to differ. There are a number of potential ethical concerns that can arise with an observation study. . This is the point at which to set out your chosen research methods, including their theoretical basis, and the literature supporting them. Such designs are also referred to as self-weighting because all sampled units are given the same weight. It also finds its applicability while questioning people in a sample survey where the interviewer may catch hold of every 10th person entering a particular shop. Therefore, the sample may not represent a cross-section of the total population. Elements are randomly selected from each stratum in each stratum in case of stratified sampling whereas only selected clusters are studied in cluster sampling. ' is not enough; there must be good academic reasons for your choice. Observations can form a part of either quantitative or qualitative research. .