It was widely believed that it was impossible to make unbiased estimates from snowball samples, but a variation of snowball sampling called respondentdriven sampling has been shown. Aug 01, 2011 leo goodman 2011 provided a useful service with his clarification of the differences among snowball sampling as originally introduced by coleman 19581959 and goodman 1961 as a means for studying the structure of social networks. It also described different form of sampling method. Assessing limitations and uses of convenience samples. However, the use of the method is not adequately explained in most studies. The question then becomes, does a snowball sample have so many flaws that the benefits of the research no longer outweigh the risks. 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. An intensity sample consists of informationrich cases that manifest the phenomenon of interest intensely but not extremely. Snowball sampling or chain referralsampling of a hidden population begins with a convenience. Sampling methods, random sampling, multistage cluster sampling, random route method, quota sampling 1.
Snowball or chain sampling involves utilizing well informed people to identify critical cases or informants who have a great deal of information about a phenomenon. Thus the sample group is said to grow like a rolling snowball. It may be extremely difficult or cost prohibitive to locate respondents in these situations. Dalam hal ini peneliti hanya mengungkapkan kriteria sebagai persyaratan untuk dijadikan sampel. This often occurs when the population is somehow marginalized, like homeless or formerly incarcerated individuals or those who are involved in illegal activities. For example, respondents who have many links are more likely to be recruited into the sample. Purposive sampling is an informant selection tool widely used in ethnobotany table 1. Snowball sampling is an approach for locating informationrich key informants1. The chain continues to refer linearly up to the end of the sampling. 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. Metode sampling yang satu ini termasuk dalam kategori nonrandom.
Freedman department of statistics university of california berkeley, ca 94720 the basic idea in sampling is extrapolation from the part to the. If youre interested in researching a specific group of people, like restaurant managers or crime victims, you need to recruit participants for your study. 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. 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. Goodmans formulation requires an initial sample drawn using a probability method on a known sampling frame.
Once you have completed the test, click on submit answers for grading to get your results. Sampling ini digunakan biasanya untuk riset eksplanatory atau uji coba kuesioner. A manual for selecting sampling techniques in research. The snowball strategy is a form of purposeful sampling in qualitative research that typically proceeds after a study begins and. For example, if you wanted to interview a sample of vegetarians cyclists people with a particular.
Stratified sampling selfselection sampling cluster sampling snowball sampling probability sampling 1. The first context involves surveying members of a rare 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. In what follows i will first supply a brief background on snowball sampling, emphasizing the methods dynamic quality. Enhancing the sample diversity of snowball samples plos. Digest successfully predicted the presidential elections in 1920, 1924,1928, 1932 but. Snowball sampling is a special nonprobability method used when.
Spatial sampling spatial sampling is an area of survey sampling associated with sampling in two or more dimensions. Used when a sampling frame not available or too expensive, and. Snowball sampling is a popular technique among social scientists who wish to work with a population that is difficult to identify or locate. Snowball sampling from a citation network at three levels. Introduction since the earliest applications of quota sampling in the early twentieth century, there has been a wealth of references to its unsuitability for some purposes, such as to obtain populationrepresentative samples 16. Misalnya ada penelitian yang bertujuan untuk mencari cara yang efektif dalam mensosialisasikan programprogram kemahasiswaan. Disadvantages a it is a difficult and complex method of samplings. A key advantage of stratified sampling is that it randomly selects elements in every stratum.
Using social media and targeted snowball sampling to. Sampling is a procedure, where in a fraction of the data is taken from a large set of data, and the inference drawn from the sample is extended to whole group. This method is used only when the population is very hardtoreach. 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 is a special nonprobability method used when the desired sample characteristic is rare. Peneliti biasanya kesulitan mencari individu yang layak dijadikan subjek. Snowball sampling adalah teknik pengambilan sampel dengan bantuan keyinforman, dan dari key informan inilah akan berkembang sesuai petunjuknya. Pengetahuan informan tentang informan lain yang potensial untuk diteliti menjadi pijakan. Snowball sampling is where research participants recruit other participants for a test or study. The researcher follows this chain of contacts in order to identify and accumulate critical cases. Because it is a snowball sampling technique, the number of potential publications gathered at each level increases exponentially and can grow quite large. Snowball sampling is defined as a nonprobability sampling technique in which the samples have traits that are rare to find.
Similar to snowball sampling, initial seed respondents recruit additional respondents from their network of friends. Snowball sampling is a commonly employed sampling method in qualitative research, used in medical science and in various social sciences. Snowball sampling isnt one of the common types of sampling methods but still valuable in certain cases. Snowball sampling research office oregon state university. This method relies on referrals from initially sampled. Raj, p4 the surveyors a person or a establishment in charge of collecting and recording data or researchers initial task is to formulate a. Types of snowball sampling linear snowball sampling is a snowball sampling in which the researcher recruits a single participant, while the second nominee recruits the third participant. Snowball sampling also called network, chain referral, or reputational sampling is a method for identifying and sampling the cases in a network. Likewise, the module on tabulation module 4 contains instructions for producing standard labour market statistics, such as the unemployment rate, that researchers can use for any number. The sampling rate is controlled purely for the sake of keeping the data collection manageable. The current participants are asked to recommend new people for the study. 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. It begins with one or a few people or cases and spreads out on the basis of links to the initial cases. The snowball metaphor relates to the fact that the study expands, using additional participants gathered from the original sample subjects and provides further elements for study of the subject.
Snowball sampling is not appropri ate in the present paper, however, because its practicality is limited to cases where respondents make a fairly small number of sociometric choices. Sociology at surrey university of surrey research socialupdate. 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. Debating the validity of snowball sampling created. In many settings where snowball sampling is used, other methods of sampling would be even worse. Theoretical and practical considerations find, read and cite all the research you need on researchgate. 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. Multiple choice questions try the multiple choice questions below to test your knowledge of this chapter. 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. In sociology and statistics research, snowball sampling is a nonprobability sampling technique. History of sampling contd dates back to 1920 and started by literary digest, a news magazine published in the u. Firstly, and most easily, as an informal method to reach a target population.
For the expert interviews, a sampling strategy has been chosen that combines elements of the maximal variation and snowball sampling procedures. Both methods categorize the target population into a certain number of groups. Sampel pertama barangkali bisa dipilih ketua bem, kepada dia kita bertanya, siapa lagi sebagai sampel ke2. Convenience sampling nonrandom sampling design elements are selected for convenience sampling because theyre available or easy to find examples. Snowball sampling adalah istilah lain dari teknik pengambilan sampel berjenjang. Jan 26, 2017 in other words, snowball sampling method is a good mechanism to obtain additional referrals from respondents to generate additional interview participants. They are also usually the easiest designs to implement. In two similar rural, predominantly hispanic counties, one of two sampling methods was selected for use in each community. Enhancing the sample diversity of snowball samples.
Comparision of snowball sampling and sequential sampling. Snowball sampling can be applied for two primary purposes. 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 paper obtained for snowball sampling based on an initial binomial sample. 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. It is a methodology where researcher recruits other individuals for the study. Since snowball samples are selected with unequal probabilities, the sample mean can no longer be used as a basis for making unbiased estimation about population characteristics. Respondent driven sampling rds is a network sampling technique typically employed for hardtoreach populations e. Sampling techniques r probability sampling e s e a r c h 2182014 sndtwu 1 4. As is typical of terms adopted by a variety of fields, however, the phrase snowball sampling is used inconsistently across disciplines.
It is used where potential participants are hard to. Snowball sampling or chainreferral sampling is defined as a nonprobability sampling technique in which the samples have traits that are rare to find. 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. The entire process of sampling is done in a single step with each subject selected independently of the other members of the.
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. The purposive sampling technique, also called judgment sampling, is the deliberate choice of an informant due to the qualities the informant possesses. Penelitian yang memanfaatkan sampel berjenjang ini memiliki kriteria lebih terbatas. A new approach to the study of hidden populations pdf. Feb 18, 2014 sampling methods random, systematic and snowball 1. Teknik sampling ini cocok dilakukan ketika jumlah populasi sulit ditentukan dan isu yang dibahas cukup sensitif. Sampling, recruiting, and retaining diverse samples. Snowball sampling or chainreferralsampling of a hidden population begins with a convenience. Creating a snowball sample to create a snowball sample, there are two steps. Sampling is defined as the process of selecting certain members or a subset of the population to make statistical inferences from them and to estimate characteristics of the whole population. That is, no correlation exists between the samples.
Sampling challenges in a study examining refugee resettlement. This article enlists the types of sampling and sampling methods along with examples. The first form of network sampling, multiplicity sampling, involved asking respondents about events affecting those in their personal networks. Purposive sampling as a tool for informant selection. While in sequential sampling, sampling was taken at a given time interval and modification can be made by. 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. Satuan sampling dipilih atau ditentukan berdasarkan informasi dari responden sebelumnya. Untuk menjawab permasalahan khusus yang sulit diungkapkan dan tidak mudah dianalisis secara statistik, maka teknik sampling. This referral technique goes on and on, increasing the size of the respondent population like a snowball rolling down a hill until the researcher. Sampling techniques r objectives e s e a r c h 2182014 sndtwu 1 3.
Intensity sampling involves the same logic as extreme case sampling but with less emphasis on the extremes. 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. Quota sampling mirip dengan sampling acak berlapis namun pemilihan elemen dari stratum tidak acak 3. 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.
Snowball sampling is a technique that can be applied in two survey contexts. This feature too is tied to the fact the snowball sampling makes use of natural social networks. Independent sampling independent samples are those samples selected from the same population, or different populations, which have no effect on one another. It also talks in detail about probability sampling methods and nonprobability sampling methods as well as the. Snowball sampling is a recruitment technique in which research participants are asked to assist researchers in identifying other potential subjects. Constrained snowball sampling limiting the percentage of articles collected at each level is presented as a feasible and effective alternative that allows for robust citation analysis using a small fraction of the data. Snowball sampling, with multiple initiation points to reduce selection bias, was necessary to locate and identify participants, provide reassurance and break down barriers. Have you ever thought about trying to get a random sample of heroin addicts. Failed in 1936 the literary digest poll in 1936 used a sample of 10 million, drawn from government lists of automobile and telephone. 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. I mean to develop methods relevant to respondents entire friendship networks, including the many people. In snowball sampling, the sample population is selected in a social context and in a multistage process, i. It is useful when the researcher know little about a group or organisation. Then i will discuss the unique relationship between snowball sampling as a data accessing method and indepth interviewing.
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. Snowball sampling in qualitative research sampling. Snowball sampling in qualitative research sampling knowledge. As the sample builds up, enough data are gathered to be useful for research.
Tawan chalalai 59376568 nadcha lujintanon 5937623438 nissareen veerasatien 5937615438 inchnok lewchalermwongse 5937652638. The second type is exponential nondiscriminative snowball sampling where every recruited. Unlike convenience samples, research subjects are selected for specific attributes that preliminary research has defined as targets. 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.
Researchers use this sampling method if the sample for the study is very rare or is limited to a. Jan 27, 2012 snowball sampling is onerous because the sample grows at an exponential rate. While these projects define themselves as global surveys, the methodology they use, and particularly the sampling methods they apply, cast doubt on the. Comparing two sampling methods to engage hardtoreach. Cluster sample a sampling method in which each unit selected is a group of persons all persons in a city block, a family, etc. Network sampling emerged as a set of methods for drawing statistically valid samples of hardtoreach populations.
Sampling objectives task 1 estimate network characteristics by sampling vertices or edges from the original networks population is the entire vertex set for vertex sampling and the entire edge set for edge sampling sampling is usually with replacement sample s sampling. Untuk menjawab permasalahan khusus yang sulit diungkapkan dan tidak mudah dianalisis secara statistik, maka teknik sampling nonprobabilitas. Personal contact was critical for both recruitment and data quality, and highlighted the importance of interviewer cultural sensitivity. The second involves studying mutual relationships among population members. Simple random sampling in this technique, each member of the population has an equal chance of being selected as subject. Snowball sampling is a wellknown, nonprobability method of survey sample selection that is commonly used to locate hidden populations. Meski demikian, dari segi akurasi, kesimpulan riset dengan snowball sampling memiliki prosentase yang cukup baik. Using social media and targeted snowball sampling to survey a. If the aim of a study is primarily explorative, qualitative and descriptive, then snowball sampling offers practical advantages hendricks, blanken and adriaans, 1992. Convenience sampling pemilihan sampel sesuai dengan keinginan peneliti.
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