Meaning and objective purposive sampling is a sampling method in which elements are chosen from among the whole population based on purpose of the study. This sampling method is used widely for consumer mail and telephone interviews. Patton 1990 has proposed the following cases of purposive sampling. Insights from an overview of the methods literature abstract the methods literature regarding sampling in qualitative research is characterized by important inconsistencies and ambiguities, which can be problematic for students and researchers seeking a clear and coherent understanding. Advantage and disadvantage of judgmental sampling, auditing. A study on purposive sampling method in research neetij rai bikash thapa chapter i. If researchers cannot find enough people or units that meet their criteria, then this process will become a waste of time and resources. Nonprobability sampling focuses on sampling techniques where the units that are investigated are based on the judgement of the researcher see our articles. Studying informationrich cases yields insights and indepth. It is characterized by a deliberate effort to obtain representative samples through the inclusion of groups or typical areas in a sample. For example, a researcher may start at a random point and take every 100th name he finds in the atlanta, georgia, telephone book. Purposive sampling an overview sciencedirect topics.
In a qualitative evidence synthesis, too much data due to a large number of studies can undermine our ability to perform a thorough analysis. Systematic sampling purposive sampling stratified sampling selfselection sampling cluster sampling snowball sampling probability sampling 1. Purposive sampling is popular in qualitative research. It avoids random sampling by targeting a specific group of people, often a small group rather than a more. Purposive sampling of primary studies for inclusion in the synthesis is one way of achieving a manageable amount of data. The main disadvantage of purposive sampling is that the vast array of inferential statistical procedures are then invalid. Advantages a it is a good representative of the population. The logic and power of purposeful sampling lie in selecting informationrich cases for study in depth. Inferential statistics lets you generalize from a particular sample to a larger population and make statements about how sure you are that you are right, or about how accurate you are. Convenience sampling and purposive sampling are nonprobability sampling techniques that a researcher uses to choose a sample of subjectsunits from a population. Purposive sampling is an acceptable kind of sampling for special situations.
Accordingly, investigator himself purposively chooses certain items which to his judgment are best representatives of the universe. Nonprobability sampling to learn more about nonprobability sampling, and sampling. In nonprobability sampling also known as nonrandom sampling not all members of the population has a chance of participating in the study. Purposive sampling is one of the most costeffective and timeeffective sampling methods available purposive sampling may be the only appropriate method available if there are only limited number of primary data sources who can contribute to the study can take a representative sample in nonrandom manner if. It uses the judgment of an expert in selecting cases or it selects cases with a specific purpose in mind. For this reason, researchers need to strive to make decisions based on.
Sampling can either be statistical or nonstatistical. Snowball sampling is most useful when there are very. If youre interested in researching a specific group of people, like restaurant managers or crime victims, you need to recruit participants for your study. Systematic sampling is similar to simple random sampling with one difference. Choosing a quota sample can be broken down into three steps.
Statistics research flexibility study good things studio back walkover studying learning. Convenience sampling pemilihan sampel sesuai dengan keinginan peneliti. Purposive sampling educational research basics by del siegle. A manual for selecting sampling techniques in research 4 preface the manual for sampling techniques used in social sciences is an effort to describe various types of sampling methodologies that are used in researches of social sciences in an easy and understandable way. One final consideration on the advantages and disadvantages of purposive sampling purposive sampling relies on the presence of relevant individuals within a population group to provide useful data. What are the merits and demerits of purposive sampling. It enables researchers to select a sample based on the purpose of the study and knowledge of a population. The use of purposeful sampling in a qualitative evidence. The objective of this article is to describe the development and application of a sampling framework for a qualitative evidence. In statistical sampling, workforce, time and money highly limits most. This is contrary to probability sampling, where each member of the population has a known, nonzero chance of being selected to participate in the study necessity for nonprobability sampling can be explained in a way that for some studies it is not.
Purposeful sampling is a technique widely used in qualitative research for the identification and selection of informationrich cases for the most effective use of limited resources patton, 2002. The strengths and weaknesses of research methodology. These do not exhaust the possibilities but illustrate some of the strategic lenses through which purposive sampling can be considered. Because, at the beginning of the study, the researcher does not know enough about a. Purposive sampling is used most often when a difficulttoreach population needs to be measured. It is scientific and every element stands an equal chance of being selected. Purposive sampling in a qualitative evidence synthesis. Simple random sampling in this technique, each member of the population has an equal chance of being selected as subject. This is a sampling technique, in which existing subjects provide referrals to recruit samples required for a research study for example, if you are studying the level of customer satisfaction among the members. They are also usually the easiest designs to implement. Disadvantages a it is a difficult and complex method of samplings.
This sampling method requires researchers to have prior knowledge about the purpose of their studies so that. Learn about its definition, examples, and advantages so that a marketer can select the right sampling method for research. Informationrich cases are those from which one can learn a great deal about issues of central importance to the purpose of the inquiry, thus the term purposeful sampling. Sampling, advantages and disadvantages of purposive sampling method, criteria set for a respondent to be included in the sample and sampling method used in this research are discussed below. The question will decide the objectives on which the methodology will be based. The main objective of purposive sampling is that the researcher, with his good decision and appropriate policy, chooses those elements which are meant for fulfilling the research objective. As defined by kerlinger 1986, purposive sampling is another nonprobability based sampling. A purposive sample, also referred to as a judgmental or expert sample, is a type of nonprobability sample. What are the merits and demerits of purposive sampling method as used in statistics. Purposive sampling is a term used for methods of choosing a nonprobability sample in a way that makes it representative of the population, although there is no generally agreed definition of a representative sample, and purposive sampling is often based on subjective considerations. However, the pros and cons of convenience sampling presented here cant be denied that although it has some advantages, it also have disadvantages.
This method of sampling is also known as subjective or judgment sampling method. They choose subjects because of certain characteristics. Purposive sampling generalizable or the existence of a particular kind of case will undermine all that you know to be true about a phenomenon, then look for that kind of case. Purposive sampling, also known as judgmental, selective or subjective sampling, is a type of nonprobability sampling technique. Qualitative, quantitative and mixed methods research characteristics table discover titles by john creswell see more.
The main objective of a purposive sample is to produce a sample that can be logically assumed to be representative of the population. Judgmental sampling, also called purposive sampling or authoritative sampling, is a nonprobability sampling technique in which the sample members are chosen only on the basis of the researchers knowledge and judgment. Researchers often believe that they can obtain a representative sample by using a sound judgment, which will result in saving time and money. Extreme or deviant case learning from highly unusual manifestations of the phenomenon of interest, such as outstanding successnotable. The main disadvantage of purposive sampling is the high probability of researcher bias, as each sample is based entirely on the judgment of the researcher in question, who generally is trying to prove a specific point. First, the researcher must divide the population of. Is convenience in reading the sampling population, mostly used among marketers or newspaper researchers.
Purposive sampling is a nonprobability sampling method and it occurs when elements selected for the sample are chosen by the judgment of the researcher. Judgmental or purposive sampling the sampling design is based on the judgement of the researcher as. Purposive sampling is a type of nonprobability sampling where the sites that are assessed are defined by the assessment team and based on the purpose of the assessment. Comparision of snowball sampling and sequential sampling. Simple random sampling and systematic sampling simple random sampling and systematic sampling provide the foundation for almost all of the more complex sampling designs based on probability sampling. Purposive sampling, also known as judgmental, selective, or subjective sampling, is a form of nonprobability sampling in which researchers rely on their own judgment when choosing members of the population to participate in their study. In statistical sampling probability sampling technique calculating the probability of getting any particular sample is possible.
Purposive sampling in qualitative inquiry is the deliberate seeking out of participants with particular characteristics, according to the needs of the developing analysis and emerging theory. It has the same advantages and disadvantages as quota sampling and it is not guided by any obvious characteristics. The first purposive sampling as a tool for informant selection ma. Purposive sampling subjects are selected because of some characteristic. It is flexible and meets multiple needs and interests. Purposive sampling pemilihan elemen untuk menjadi sampel berdasarkan pertimbangan yang tidak acak, subyektif 2. Using the purposive sampling method in choosing a sampling method for informant selection, the question the researcher is interested in answering is of utmost importance. Researchers use the simple random sample methodology to choose a subset of individuals from a larger population. Pdf comparison of convenience sampling and purposive. This is often accomplished by applying expert knowledge of the population to select in a nonrandom manner. A site is a geographical location with a specific characteristic where we will conduct a community. The primary objective of this type of nonprobability sample is to produce a. Snowball sampling or chainreferral sampling is defined as a nonprobability sampling technique in which the samples have traits that are rare to find. Quota sampling is a nonprobability sampling technique in which researchers look for a specific characteristic in their respondents, and then take a tailored sample that is in proportion to a population of interest how to choose a quota sample.