In both cases, respondents are expected to know about the identity of other members of the. Enhancing the sample diversity of snowball samples plos. Snowball sampling is a special nonprobability method e for developing a research sample where existing study subjects recruit future subjects from among their acquaintances. 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.
The purposive sampling technique, also called judgment sampling, is the deliberate choice of an informant due to the qualities the informant possesses. Snowball sampling is a special nonprobability method used when. In simple terms, in multistage sampling large clusters of population are divided into smaller clusters in several stages in order to make primary data collection more manageable. As the sample builds up, enough data are gathered to be useful for. Snowball sampling or chainreferral sampling is defined as a nonprobability sampling technique in which the samples have traits that are rare to find. This is the purest and the clearest probability sampling design and strategy. Snowball sampling is a technique that can be applied in two survey contexts. It is useful when the researcher know little about a group or organisation. Snowball sampling snowball sampling 5 is usually done when there is a very small population size.
The use of virtual sampling was combined with an online questionnaire as a complementary tool for web 2. Snowball sampling is a commonly employed sampling method in qualitative research, used in medical science and in various social sciences, including sociology, political science, anthropology and human geography. To assess the representativeness of samples obtained by snowball sampling, we compared participants in the pooled snowball surveys to participants in a mail survey conducted in 1996 in a representative sample of the geneva population. Stratified sampling selfselection sampling cluster sampling snowball sampling probability sampling 1. Snowball sampling is undertaken when a qualified participant shares an invitation with other subjects similar to them who fulfill the qualifications defined for the targeted population berg, 2006.
Pdf snowball sampling is a wellknown, nonprobability method of. Comparision of snowball sampling and sequential sampling. This involves identifying and selecting individuals or groups of individuals that are especially knowledgeable about or experienced with a phenomenon of. Goodmans formulation requires an initial sample drawn using a probability method on a known sampling frame. Purposive sampling as a tool for informant selection.
Snowball sampling problems and techniques of chain referral sampling patrick blernackl sun francisco state university dan waldorf pacific institute for research and evaluation nowball or chain referral sampling is a method that has s been widely used in qualitative sociological research. Snowball sampling has been widely used in qualitative sociological research, especially in the study of deviant behavior and is used in the place where the population is hard to reach. Raj, p4 all these four steps are interwoven and cannot be considered isolated from one another. Using social media and targeted snowball sampling to. These actors may themselves open possibilities for an expanding web of contact. The use of currently enrolled research participants to recruit additional research participants sometimes referred to as the snowball sampling may be approved by the irb under some circumstances. In sociology and statistics research, snowball sampling or chain sampling, chainreferral sampling, referral sampling is a nonprobability sampling technique where existing study subjects recruit future subjects from among their acquaintances. Snowball sampling may be defined as a technique for gathering research subjects through the identification of an initial subject who is used to provide the names of other actors. Snowball sampling social research update university of surrey.
Snowball sampling is a recruitment technique in which research participants are asked to assist researchers in identifying other potential subjects. Snowball sampling is a type of convenience sampling method that is usually applied when it is difficult to acquire respondents with target characteristics naderifar et. The article provides a description and analysis of some of the problems that were encountered and resolved in the course of using the method in a relatively large exploratory study of exopiate addicts. Snowball sampling research office oregon state university. Appendix iii is presenting a brief summary of various types of nonprobability sampling technique. The procedures of chain referral sampling are not selfevident or obvious. For example, if you are studying the level of customer satisfaction among elite nirvana bali golf club in bali, you will find it increasingly difficult to find primary data sources unless a member is. This sampling technique is often used in hidden populations which are difficult for researchers to. A manual for selecting sampling techniques in research 5 of various types of probability sampling technique.
In sociology, snowball sampling refers to a nonprobability sampling technique which includes purposive sampling in which a researcher begins with a small population of known individuals and expands the sample by asking those initial participants to identify others that should participate in the study. Purposeful sampling for qualitative data collection and. A manual for selecting sampling techniques in research. 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. Please note that some file types are incompatible with some mobile and tablet devices. Sampling theory chapter 4 stratified sampling shalabh, iit kanpur page 5 now 1 1 1 1 k stii i k i i i ey ney n ny n y thus yst is an unbiased estimator of y. The second involves studying mutual relationships among population members. A sampling technique in which each unit in a population has a. The entire process of sampling is done in a single step with each subject selected independently of the other members of the. The words that are used as synonyms to one another are mentioned. Some fixedsample ranking and selection problems mahamunulu, d. Untuk menjawab permasalahan khusus yang sulit diungkapkan dan tidak mudah dianalisis secara. Snowball sampling has been widely used in qualitative sociological research, especially in the.
Simple random sampling in this technique, each member of the population has an equal chance of being selected as subject. It begins with one or a few people or cases and spreads out on the basis of links to the initial cases. Enhancing the sample diversity of snowball samples. 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. Representing against population with a subset of it is termed as sampling. It also described different form of sampling method. Tongco purposive sampling as a tool for informant selection botany. In other words, the sample starts small but snowballs into a larger. In other words, snowball sampling method is a good mechanism to obtain additional referrals from respondents to generate additional interview participants.
One subject gives the researcher the name of another subject, who in turn provides the name of a third, and so on vogt, 1999. Probability sampling means that every member of the population has a chance of being selected. This is a sampling technique in which existing subjects provide referrals to recruit samples required for. The variables to which the sample is drawn up are linked to the research question. In other words, the sample starts small but snowballs into a larger sample through the. The technique is a kind of statistically non representative stratified sampling because, while it is similar to its quantitative counterpart, it must not be seen as a sampling strategy that allows statistical generalisation to the large population. Pengertian secara umum ada dua teknik sampling yang dapat digunakan, yaitu sampling probabilitas yang cenderung bersifat kuantitatif dengan analisis statistik, dan teknik sampling nonprobabilitas yang cenderung bersifat kualitatif. The downside of using a snowball sample is that it is hardly representative of the population. This technique is used in the situations where the population is completely unknown and rare. The snowball sampling is a research technique through survey and data registration which. Snowball sampling is a nonprobability sampling technique that is used by researchers to identify potential subjects in studies where subjects are hard to locate.
As is typical of terms adopted by a variety of fields, however, the phrase snowball sampling is used inconsistently across. If you want to produce results that are representative of the whole population, you need to use a probability sampling technique. The first context involves surveying members of a rare population. Multistage sampling also known as multistage cluster sampling is a more complex form of cluster sampling which contains two or more stages in sample selection. This article attempts to rectify this methodological neglect. Pdf comparision of snowball sampling and sequential. Purposive sampling differs from several other kinds of sampling, snowball sampling, and random sampling. While these projects define themselves as global surveys, the methodology they use, and particularly the sampling methods they apply, cast doubt on the. Beginning with the premise that research is formed, the paper offers one account of snowball sampling and using social networks to make research. Snowball sampling one method that is becoming increasingly popular to recruit subjects is snowball sampling. In this type of sampling, the researcher asks the initial subject to identify another potential subject who also meets the criteria of the research.
Pdf comparision of snowball sampling and sequential sampling. This approach allows you to utilise the original group as informants who can help in identifying additional people to interview who qualify for inclusion and these, in turn, identify yet. This article explains a what snowball sampling is, b how to create a snowball. Comparision of snowball sampling and sequential sampling technique. Sampling can either be statistical or nonstatistical. Thus the sample group is said to grow like a rolling snowball. This paper explores snowball sampling, a recruitment method that employs research into participants social networks to access specific populations. Simple random sampling, systematic sampling, stratified sampling fall into the category of simple sampling techniques. Snowball sampling also called network, chain referral, or reputational sampling is a method for identifying and sampling the cases in a network. It is also the most popular way of a selecting a sample because it creates samples that are very highly representative of the population simple random is a fully random technique of selecting subjects. Snowball sampling also known as chainreferral sampling is a nonprobability nonrandom sampling method used when characteristics to be possessed by samples are rare and difficult to find. Some remarks on systematic sampling gautschi, werner, annals of mathematical statistics, 1957. For example, if you are studying the level of customer satisfaction among elite nirvana bali golf club in bali, you will find it increasingly difficult to find primary data sources unless a. Therefore we will take the help from the first element which we select for the population and ask him to recommend other elements who will fit the description of the sample needed.
An example of the use of snowball sampling in a doctoral research project, which looks at the experiences of black. It is a nonrandom technique that does not need underlying theories or a set. Snowball sampling snowball sampling may simply be defined as. Nonprobability sampling focuses on sampling techniques that are based on the judgement of the researcher see our article nonprobability sampling to learn more about nonprobability 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. Researchers use this sampling method if the sample for the study is very rare or is limited to a very small subgroup of the population.
Design for the control of selection bias blackwell, david and hodges, j. Snowball sampling is a type of nonprobability sampling technique. If youre interested in researching a specific group of people, like restaurant managers or crime victims, you need to recruit participants for your study. This sampling technique offers practical advantages such as having the social networks of identified participants that can provide an ever. In snowball sampling, the sample population is selected in a social context and in a multistage process, i. Snowball sampling or chainreferral sampling is defined as a a nonprobability sampling technique in which the samples have traits that are rare to find. Sociology at surrey university of surrey research socialupdate.
354 376 883 1417 1079 1007 1478 772 153 1192 1258 1184 891 374 1376 1184 1048 64 792 147 1295 1281 167 397 1366 1257 391 593 1233 1238 358 1423 704 108 1385 760 421 976 394 313 1221 774 1295 23 1159