Snowball sampling is a special nonprobability method used when. One subject gives the researcher the name of another subject, who in turn provides the name of a third, and so on vogt, 1999. Thus, this method is also called as the referral sampling method or chain sampling method. Oct 28, 2016 in two similar rural, predominantly hispanic counties, one of two sampling methods was selected for use in each community. One of the reasons that it is most often used is due to the numerous advantages it provides.
Snowball sampling is a wellknown, nonprobability method of survey sample selection that is commonly used to locate hidden populations. In other words, snowball sampling method is a good mechanism to obtain additional referrals from respondents to generate additional interview participants. Convenience sampling can be used by almost anyone and has been around for generations. Sociology at surrey university of surrey research socialupdate. Unlike convenience samples, research subjects are selected for specific attributes that preliminary research has defined as targets. This referral technique goes on and on, increasing the size of the respondent population like a snowball rolling down a hill until the researcher. 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.
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. Systematic sampling is often used instead of random sampling. The snowball sampling is a nonrandom sampling technique wherein the initial informants are approached who through their social network nominate or refer the participants that meet the eligibility criteria of the research under study. Pdf snowball sampling is a wellknown, nonprobability method of survey sample selection that is commonly used to locate hidden. Snowball sampling has advanced as a technique and the literature contains evi dence of a trend toward more sophisti cated methods of sampling frame and. Snowball sampling friend of friend you initially contact a few potential respondents and then ask them whether they know of anybody with the same characteristics that you are looking for in your research. Vancouver, canada, using the method of snowball sampling.
When conducting quota sampling, a researcher identifies categories that are important to the study and for which there is likely to be some variation. It is useful when the researcher know little about a group or organisation. Then judgment is used to select the subjects or units from each segment based on a specified. 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. As long as the list does not contain any hidden order, this sampling method is as good as the random sampling method. Sampling challenges in a study examining refugee resettlement. Due to sampling difficulties, refugeefocussed research projects often either utilise existing epidemiological databases, are conducted on a large scale through governmental or health organisations. One method that is becoming increasingly popular to recruit subjects is snowball sampling. While in sequential sampling, sampling was taken at a given time interval and modification can be made by correcting the research and sampling method to centralize the analysis and make a satisfied decision. Some fixedsample ranking and selection problems mahamunulu, d. Pdf on sep 30, 2017, mahin naderifar and others published snowball sampling. It is as if the use of the snowball method entailed little more than to start it rolling through a personal contact or through an informant and then simply to sit back and allow the resulting chain to follow its own course.
Feb 21, 2014 sampling, ppt, business research, swati luthra slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. 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. In total, 622 injecting drug users with hiv and 1429 injecting. 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. Snowball sampling snowball sampling is a recruitment method in which an investigator enlists the help of a research subject in identifying, and possibly recruiting, additional subjects. Two types of sampling errors biased errors due to selection of sampling techniques. Pdf comparision of snowball sampling and sequential sampling.
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. While these projects define themselves as global surveys, the methodology they use, and particularly the sampling methods they apply, cast doubt on the. Snowball sampling is a technique where a researcher picks the first few samples and either recruits them or asks them to recommend other subjects they know who fit the description of samples needed. Snowball sampling uses a method beloved by sales people, where customer referrals to new prospects have particular value as the relationship of trust and obligation between the identified person and the referrer makes it more likely that the new person will make a purchase. A starting point between 1 and n is then randomly selected, and the sample is then formed from every nth person. This method relies on referrals from initially sampled. If youre interested in researching a specific group of people, like restaurant managers or crime victims, you need to recruit participants for your study. After the required sample size has been calculated, every nth record is selected from a list of population members. Snowball sampling is a nonprobability based sampling technique that can be used to gain access to such populations.
In two similar rural, predominantly hispanic counties, one of two sampling methods was selected for use in each community. Snowball sampling is a commonly employed sampling method in qualitative research. Enhancing the sample diversity of snowball samples plos. Sampling the process of using a small number of items or parts of larger population to make a conclusions about the whole population. Snowball sampling is a nonprobability sampling technique that is used by researchers to identify potential subjects in studies where subjects are hard to locate. Snowball sampling social research update university of surrey. In this study we aim to test whether results from a quota sample, believed to be the nonprobability sampling method that is the closest in representativeness to probability sampling, are statistically equivalent to those from a probability. This method is often used instead of random sampling. In section 6 of the present paper some results for snowball sampling based on an initial sample of the more usual kind are obtained and compared with results presented in the earlier sections of. This method was initially developed as part of a nihnidafunded hiv prevention project in connecticut heckathorn. This sampling method generates biased samples because respondents who have great number of social connections are able to provide. For example, if you wanted to interview a sample of vegetarians cyclists people with a particular. Snowball sampling or chainreferral sampling is defined as a nonprobability sampling technique in which the samples have traits that are rare to find. Feb 24, 2017 04 sampling population sample and generalizability duration.
Using social media and targeted snowball sampling to survey a. In spite of the widespread use of chain referral sampling in. Snowball sampling is undertaken when a qualified participant shares an invitation with other sub jects similar to them who fulfill the qualifications defined for the targeted population berg. The term snowball is used to represent a sampling method that relies on one participant recruiting friends and. According to research mentioned in the paper written by kath browne, using social networks to research is accessible. The total number of units in the experimental population divided by the number of units to be selected. A purposeful method of sampling in qualitative research. The need to samplesampling a valid alternative to a census. The way that the sample is chosen by target people makes it liable to. Snowball sampling also called network, chain referral, or reputational sampling is a method for identifying and sampling the cases in a network.
If you continue browsing the site, you agree to the use of cookies on this website. In this research, kath browne used social networks to research nonheterosexual women. Snowball sampling in qualitative research sampling. It is useful when the investigator may not have access to a population of potential subjects who meet inclusion criteria, which may often be stigmatizing. 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. Snowball sampling is a recruitment method that employs research into participants social networks to access specific populations. This paper describes a practical method for sampling average acquaintance volume the average number of people known. Design for the control of selection bias blackwell, david and hodges, j. Some remarks on systematic sampling gautschi, werner, annals of mathematical statistics, 1957. Snowball sampling is a type of nonprobability sampling technique. Some first steps mark granovetter harvard university social network research has been confined to small groups because large networks are intractable, and no systematic theory of network sampling exists. It is equal to random sampling as long as no particular order exists in the list. Engaging marginalized populations in holistic research abstract womanist and feminist qualitative researchers continue to identify research methods and techniques that harness the power of social networking and personal connections while engaging with marginalized populations. 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 article explains a what snowball sampling is, b how to create a snowball. In quota sampling, a population is first segmented into mutually exclusive subgroups, just as in stratified sampling. Snowball sampling in qualitative research sampling knowledge. The variables to which the sample is drawn up are linked to the research question. Debt snowball pays off the smallest bills first, motivating to keep going. One of the most wellknown forms of nonprobability sampling is the snowball sampling method, which is particularly suitable when. Researchers use this sampling method if the sample for the study is very rare or is limited to a. Introduction we cannot ignore the importance of virtual relationships on people lives.
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 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. In other words, the sample starts small but snowballs into a larger. Learn how you can pay down debt and use our debt snowball calculator. This method is extremely speedy, easy, readily available, and cost effective, causing it to be an attractive option to most researchers. Quota sampling is a method for selecting survey participants that is a nonprobabilistic version of stratified sampling.
Salganik abstract hidden populations, such as injection drug users and sex workers, are central to a number of public health problems. Variance estimation, design effects, and sample size. Selecting samples population, sample and individual cases source. Nonprobability sampling is a sampling procedure that will not bid a basis for any opinion of probability that elements in the universe will have a chance to be included in the study sample. The current participants are asked to recommend new people for the study. The judgment that chainreferral sampling is a convenience method was challenged in a series of papers leading to the development of a new method for collecting and analyzing chainreferral data, respondentdriven sampling rds.
Media and targeted snowball sampling 282 ples and the asystematic recruitment of research subjects in convenience samples on the one hand and the more rigid cluster and stratified samples on the other. First the total target group number x is divided by the required sample size number y to create the sampling interval n. The errors which arise due to the use of sampling surveys are known as the sampling errors. Snowball sampling is a technique used by researchers primarily when they are researching hidden populations or subcultures such as drug users. Then i will discuss the unique relationship between snowball sampling as a data accessing method and indepth interviewing downloaded by hebrew university at 23. Jan 26, 2017 in other words, snowball sampling method is a good mechanism to obtain additional referrals from respondents to generate additional interview participants. Unbiased errors random sampling errorsdifferences between the members of the population included or not included.
How to use debt snowball to pay off debt nerdwallet. Rds is not a variant of either usage of snowball sampling, nor is the reverse true. This innovative method however comes with limits, such that the reconstruction algorithm is unstable and physically nonrealizable. This type of sampling is actually employed by both qualitative and quantitative researchers, but because it is a nonprobability method, well discuss it in this section. Snowball sampling definition of snowball sampling by.
Hence snowball sampling and respondentdriven sampling allow participants to make estimates about the social network connecting the hidden population. Snowball sampling is defined as a nonprobability sampling technique in which the samples have traits that are rare to find. We are going to see from diverse method of five different sampling considering the nonrandom designs. Comparision of snowball sampling and sequential sampling. Variance estimation, design effects, and sample size calculations for respondentdriven sampling matthew j. Aug 01, 2011 the judgment that chainreferral sampling is a convenience method was challenged in a series of papers leading to the development of a new method for collecting and analyzing chainreferral data, respondentdriven sampling rds. Aug 07, 2017 calculating the confidence interval for a mean using a formula statistics help duration. In what follows i will first supply a brief background on snowball sampling, emphasizing the methods dynamic quality. It begins with one or a few people or cases and spreads out on the basis of links to the initial cases. Using social media and targeted snowball sampling to.
146 127 1017 1541 544 125 1250 1479 1092 1318 1583 770 455 1272 1037 872 684 600 399 161 911 1501 508 1539 372 909 1272 456 935 1002 1005 1273 545 13 206