Dec 04, 2018 the snowball sampling method is extensively used where a population is unknown and rare and it is tough to choose subjects to assemble them as samples for research. Sampling process may encounter the problem of systematic errors and sampling biases. This is a sampling technique in which existing subjects provide referrals to recruit samples required for a research study. Systematic errors can be defined as incorrect or false representation of the sample. The current participants are asked to recommend new people for the study.
The procedures of chain referral sampling are not selfevident or obvious. Snowball sampling is a sampling technique to gather data or information from a specific group of people 27 and mostly used to study hidden population 28. Snowball sampling is a commonly employed sampling method in qualitative research. Snowball sampling research office oregon state university.
The snowball sampling is a research technique through survey and data. Snowball sampling is a type of nonprobability sampling technique. Purposive sampling is an informant selection tool widely used in ethnobotany table 1. This paper focuses on snowball sampling procedures, which we define as those actions undertaken to initiate, progress and terminate the snowball sample 1, 20. Surveys of housing units, where an individual is asked who lives in the house, frequently misses some people. 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. The number of people you have access to snowballs as you get in contact with more people. Pdf in order to answer the research questions, it is doubtful that researcher should be able to collect data from all cases.
Sociology at surrey university of surrey research socialupdate. Types of nonprobability random sampling quota sampling. 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. Heterogeneity sampling is, in this sense, almost the opposite of modal instance sampling. 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. 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. The central problem is that these so called global surveys are usually performed on a series of nationally defined and bounded samples. Thus the sample group is said to grow like a rolling snowball. In this blog you will read about the types and method of snowball sampling along with its advantages and disadvantages. According to research mentioned in the paper written by kath browne, using social networks to research is accessible.
For example, many sexual assault survivors are reluctant to talk about their experiences and avoid identifying themselves as survivors. Aug 22, 2018 snowball sampling is a commonly employed sampling method in qualitative research. Target populations, sampling frames, and coverage error. Its called snowball sampling because in theory once you have the ball rolling, it picks up more snow along the way and becomes larger and larger. Scholars have posited several anecdotally based recommendations for enhancing the diversity of. This method relies on referrals from initially sampled.
This is not therefore a random sample and no inferences about the characteristics of the parent population can be made from such a study. One subject gives the researcher the name of another subject, who in turn provides the name of a third, and so on vogt, 1999. Munich personal repec archive a manual for selecting sampling techniques in research alvi, mohsin university of karachi, iqra university 23 march 2016 online at mpra paper no. Jan 26, 2017 judging by the numbers of views these two posts have accumulated it is clear that there is a demand for this type of discussion in a clear and concise manner. Enhancing the sample diversity of snowball samples. 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 is a nonrandom sampling method that uses to. Simple random sampling in this technique, each member of the population has an equal chance of being selected as subject.
January 26, 2017 the triangle admin leave a comment. As the sample builds up, enough data are gathered to be useful for research. It is to this end that today i discuss another very popular method of sampling, known as snowball sampling. Snowball sampling is where research participants recruit other participants for a test or study.
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. Snowball sampling is defined as a nonprobability sampling technique in which the samples have traits that are rare to find. 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. Its use is primarily in the collection of indepth, qualitative data, perhaps on sensitive topics, where an obvious. The purposive sampling technique, also called judgment sampling, is the deliberate choice of an informant due to the qualities the informant possesses. In the past i have spoken about some of these in detail, for example i mention and discuss from a holistic perspective.
Yin 2011 deciding on issues for the quintain stake, 2005b theore1cal samplingongoing sampling merriam, 2009 used to sample within the case a ongoing sampling is less emphasized in phenomenology or case study. Yin 2011 deciding on issues for the quintain stake, 2005b theore1cal sampling ongoing sampling merriam, 2009 used to sample within the case a ongoing sampling is less emphasized in phenomenology or case study. Thus, this method is also called as the referral sampling method or chain sampling method. Sampling procedure 1 of 2 sampling procedure definition sample. Snowball sampling is used in this research to reveal every actor involved in each case either directly or indirectly. Stratified sampling selfselection sampling cluster sampling snowball sampling probability sampling 1. Scholars have posited several anecdotally based recommendations for enhancing the diversity of snowball samples. This article attempts to rectify this methodological neglect. 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. In snowball sampling, you begin by identifying someone who meets the criteria for inclusion in your study. The variables to which the sample is drawn up are linked to the research question. 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. There are many many different ways to develop your sampling strategy. A qualitative sampling plan describes how many observations, interviews, focusgroup discussions or cases are needed to ensure that the findings will contribute rich data.
One subject gives the researcher the name of another subject, who in turn. Snowball sampling is a recruitment method that employs research into participants social networks to access specific populations. The sampling method used for the survey was snowball sampling. Nonprobability sampling research methods knowledge base. Snowball sampling one method that is becoming increasingly popular to recruit subjects is snowball sampling. Used to choose the number of participants, interviews, or work samples to use in the assessment process. A sampling plan is a formal plan specifying a sampling method, a sample size, and procedure for recruiting participants box 1. Snowball sampling or chainreferral sampling is defined as a a nonprobability sampling technique in which the samples have traits that are rare to find. These actors may themselves open possibilities for an expanding web of contact.
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. In this research, kath browne used social networks to research nonheterosexual women. However, the use of the method is not adequately explained in most studies. Snowball sampling is a recruitment technique in which research participants are asked to assist researchers in identifying other potential subjects.
Comparision of snowball sampling and sequential sampling. Goodmans formulation requires an initial sample drawn using a probability method on a known sampling frame. 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. Despite the lack of substantive writing on snowball sampling as a method, several authors 2, 3, 21 have provided. From the listed the researcher has to deliberately select items to be sample. Snowball sampling is an approach for locating informationrich key informants1. Snowball sampling is a special nonprobability method used when. Snowball sampling is a type of convenience sampling method that is usually applied when it is difficult to acquire respondents with. 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. Linear snowball sampling is a snowball sampling in which the researcher recruits a single participant, while the second nominee recruits the third participant.
A manual for selecting sampling techniques in research. 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. Snowball sampling definition of snowball sampling by. Using this approach, a few potential respondents are contacted and asked whether they know of anybody with the characteristics that you are looking for in your research. Division of academic and student affairs office of assessment sampling procedure 1 of 2 sampling procedure definition sample. Snowball sampling can present significant ethical problems, especially if the research topic is sensitive or personal.
For example, if you are studying the level of customer satisfaction among elite nirvana bali golf club in. Snowball sampling is a wellknown, nonprobability method of survey sample selection that is commonly used to locate hidden populations. This definition can initially seem selfexplanatory, which may explain why. This article explains a what snowball sampling is, b how to create a snowball sample, and c the advantages. It is used where potential participants are hard to. Snowball sampling definition in the cambridge english. Enhancing the sample diversity of snowball samples plos. Using social media and targeted snowball sampling to. Broaden definition of who can be in sampling frame idea. You then ask them to recommend others who they may know who also meet the criteria. Purposive sampling as a tool for informant selection. Jan 27, 2012 the use of virtual sampling was combined with an online questionnaire as a complementary tool for web 2. Quota sampling, accidental sampling, judgemental sampling or purposive sampling, expert sampling, snowball sampling, modal instant sampling.
This method relies on referrals from initially sampled respondents to other persons believed to have the characteristic of interest. The entire process of sampling is done in a single step with each subject selected independently of the other members of the. It is used where potential participants are hard 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. Snowball sampling is a popular technique among social scientists who wish to work with a population that is difficult to identify or locate. The use of virtual sampling was combined with an online questionnaire as a complementary tool for web 2. Unlike convenience samples, research subjects are selected for specific attributes that preliminary research has defined as targets.
Snowball sampling is a technique used by researchers primarily when they are researching hidden populations or subcultures such as drug users. Snowball sampling social research update university of surrey. 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. Pdf snowball sampling is a wellknown, nonprobability method of survey sample selection that is commonly used to locate hidden. Untuk menjawab permasalahan khusus yang sulit diungkapkan dan tidak mudah dianalisis secara statistik, maka teknik sampling non. A researcher using snowball sampling can keep participants anonymous in published papers. You are researching experiences of homelessness in your city. Wecanuseprobabilitysamplingtechniquesonlywhenwecanhavea. The term snowball is used to represent a sampling method that relies on one participant recruiting friends and acquaintances from. Broaden the definition of who can be in the sampling frame, then screen out as necessary incurs extra costs and requires additional effort example. 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 article about snowball sampling by the. If the population is hard to access, snowball sampling can be used to recruit participants via other participants.