Sampling

Sampling

Introduction

The problem of collecting appropriate data for studying certain phenomena is one of the main difficulties facing the researcher when framing the methodological design. Furthermore, there are cases in which the barriers of access to information determine the choice of the method of addressing the problem, focusing on the scope and representation of the results to be found. The impossibility of probability samples is the most important operating condition the study of many populations of interest is difficult to approach (lack of population, sensitivity on the subject, geographical dispersion, etc.). This paper will be discussing the external validity of the sampling methods and also the affects of poor sampling frame on the results of the overall research process. Such is its importance that the sampling phase is determining the definition of the methodology and data collection techniques and influences the validity and scope of the results of the investigation. In this context, the application of methodologies requires a quantitative sample size that would ensure adequate representation and / or generalization of the results, while in the case of qualitative methodology; the analysis focuses in depth study of small groups, prioritizing the wealth of information (Denzin & Lincoln, 2000). For studies of populations with difficult access (hard to reach) to develop a design mixed, the researcher faces problems for instance: first, to achieve a sample size suitable for applying quantitative methodology and, secondly, to ensure that the units of observation selected for the qualitative work are representative of the population. Also, the application of mixed methods, simultaneous or sequential, can be a difficult strategy to conduct and is the cost of execution or the time required to obtain results. Therefore, this paper will focus on finding the issues related to the sampling.

The Sampling Frame: Most Critical Element of a Study's Sampling Plan

The sampling frame is of significant importance while studying sampling plan. The sampling frame is the instrument used to cover a representative selection of particular communities of an area under study. For instance; in the studies related to medical and health issues, a research form a sampling frame according to which population sample will be taken according to some specified demographics and of particular area in which same type of health issue has been identified, For example; If a researcher wants to study the prevalence of HIV /AIDS in people of some particular community, he should have specified the community, ages and gender of the populations selected for carrying out study(Rubin & Babbie, 2001). By doing so, creation of sampling plan will be easier to understand and the number of sample size selected will be much easier to communicate. However, the choice of a particular procedure, separation and preparation of one or more samples from the batch or area of study, designed to achieve the desired information of the material or the study area is known as sampling plan.

Sampling Terminology

Following is the sampling terminology according to which the :

Target Population: all individuals from whom information is to ...