In this method, personal knowledge and opinion are used to identify the individualsitems from the population. Snowball sampling social research update university of surrey. The technique works like a chain referral system where existing study subjects recruit additional subjects from their contact groups. Sampling methods a great deal of sociological research makes use of sampling. Nonrandom or nonprobability sampling the methods that sampling units being selected on the basis of personal judgment is called nonprobability sampling. Sampling is the process of selecting a subset of the population for analysis to save time and resources. First, the researcher must divide the population of. The article provides the description and comparison of two nonrandom samplings which are snowball or chain referral sampling and sequential sampling.
It is useful when the researcher know little about a group or organisation. 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. The aim of this paper is to present a sampling method using virtual networks to study hard. Enhancing the sample diversity of snowball samples. Snowball sampling or chainreferral sampling is defined as a a nonprobability sampling technique in which the samples have traits that are rare to find. A research on the habits, thoughts, views, and opinions of people can help us in the betterment of the society. Disadvantages of snowball sampling the disadvantages of this approach include firstly oversampling. Snowball sampling is defined as a nonprobability sampling technique in which the samples have traits that are rare to find. Pdf comparision of snowball sampling and sequential. Choosing a quota sample can be broken down into three steps.
The chain continues to refer linearly up to the end of the sampling. Snowball sampling is a term used for sampling procedures that allow the sampled units to provide information not only about themselves but also about other units. Snowball sampling research office oregon state university. Snowball sampling is a wellknown, nonprobability method of survey sample selection that is commonly used to locate hidden populations. Then i will discuss the unique relationship between snowball sampling as a data accessing method and indepth interviewing. Then, the researcher will select each nth subject from the list. Several years after colemans and goodmans development of snowball sampling, what was also termed snowball sampling emerged as a nonprobability approach to. If youre interested in researching a specific group of people, like restaurant managers or crime victims, you need to recruit participants for your study. Formation of a sample group starts with only one subject and the subject provides only one referral. This method relies on referrals from initially sampled respondents to other persons believed to have the charac teristic of interest. The researcher has little control over the sampling method. Convenience sampling involves choosing respondents at the convenience of the researcher. The referral is recruited into the sample group and heshe also provides only one new referral.
Where to use snowball sampling for some populations, snowball sampling is the only viable sampling strategy because the study group is secretive or hard to reach because of social stigma, illegality of their work or lack of data. Snowball sampling in qualitative research sampling. There are several wellknown disadvantages of snowball sampling. 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. Snowball sampling has been found to be economical, efficient and effective in various studies. Systematic sampling is a random sampling technique which is frequently chosen by researchers for its simplicity and its periodic quality. When you use purposive sampling for information collection, then you will discover that there is a vast array of inferential statistical procedures that are present in this structure.
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. It is used where potential participants are hard to find. Snowball sampling is also called chain referral sampling. Snowball sampling is a type of nonprobability sampling technique. Sampling methods random, systematic and snowball 1.
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. As described in leo goodmans 2011 comment, snowball sampling was developed by coleman 19581959 and goodman 1961 as a means for studying the structure of social networks. In snowball sampling, the sample population is selected in a social context and in a multistage process, i. 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. These actors may themselves open possibilities for an expanding web of contact. 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. The procedures of chain referral sampling are not selfevident or obvious. 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. 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.
One of the dangers with snowball sampling is that respondents often suggest. 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. The subjects that the researcher can obtain rely mainly on the. Snowball sampling has been widely used in qualitative sociological research, especially in the. 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. A manual for selecting sampling techniques in research. It provides a significant number of inferential statistical procedures that are invalid. In this regard, the authors hypothesis is that the use of social networking sites web 2. Sampling techniques r objectives e s e a r c h 2182014 sndtwu 1 3. If the aim of a study is primarily explorative, qualitative and descriptive, then snowball sampling offers practical advantages hendricks, blanken and adriaans, 1992.
Representativeness of the sample is not guaranteed. If you oversample from one particular network this may bias some of your data. In other words, snowball sampling method is a good mechanism to obtain additional referrals from respondents to generate additional interview participants. Snowball sampling is where research participants recruit other participants for a test or study. Snowball sampling is where research participants recruit other participants for a test.
Check the advantages and disadvantages of convenience sampling. This article attempts to rectify this methodological neglect. The limitations of this study, which are mostly related. However, you should be fully aware of the pros and cons of convenience sampling before you conduct research. 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 one of the most popular methods of sampling in qualitative research, central to which are the characteristics of networking and referral. 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. Snowball sampling is a commonly employed sampling method in qualitative research. The entire process of sampling is done in a single step with each subject selected independently of the other members of the. The subjects that the researcher can obtain rely mainly on the previous subjects that were observed. Thus the sample group is said to grow like a rolling snowball.
Comparision of snowball sampling and sequential sampling. Sampling techniques r probability sampling e s e a r c h 2182014 sndtwu 1 4. In other words, the sample starts small but snowballs into a larger sample through the. Using social media and targeted snowball sampling to. The solution is snowball sampling, a practice in which a small group of initial participants help researchers find more participants by accessing their social networks. In statistical research, snowball sampling is a nonprobability method used for rare studies or research limited to rare small groups of population. Assessing limitations and uses of convenience samples. In the field of research different sampling technique are used for different fields.
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 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. 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.
Pdf snowball sampling is a wellknown, nonprobability method of. The second type is exponential nondiscriminative snowball sampling where every recruited. Firstly, and most easily, as an informal method to reach a target population. Pros and cons of different sampling techniques international. Sociology at surrey university of surrey research socialupdate. 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. They are also usually the easiest designs to implement. This feature too is tied to the fact the snowball sampling makes use of natural social networks. Goodmans formulation requires an initial sample drawn using a probability method on a known sampling frame. Snowball sampling can be applied for two primary purposes.
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. Unlike convenience samples, research subjects are selected for specific attributes that preliminary research has defined as targets. Snowball sampling is a recruitment technique in which research participants are asked to assist researchers in identifying other potential subjects. Sampling from populations in which individuals are hard to identify can justify clever approaches, but the role of the simple random sampling model in. For example, it has been shown to be capable of producing. As the sample builds up, enough data are gathered to be useful for research. Snowball sampling is convenient, but has significant limitations. In systematic random sampling, the researcher first randomly picks the first item or subject from the population. The researcher has no idea of the true distribution of the population and of the sample.
As is typical of terms adopted by a variety of fields, however, the phrase snowball sampling is used inconsistently across disciplines. The researchers usually start with a small number of initial contacts seeds who fit the research criteria and are invited to become participants within the research. 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. 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 pattern is continued until the sample group is fully formed. 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. For example, if you wanted to interview a sample of vegetarians cyclists people with a particular. One of the most obvious limitations of simple random sampling method is. Quota sampling is a type of nonprobability sampling technique. This article explains a what snowball sampling is, b how to create a snowball sample, and c the advantages.
This is a technique aiming to reduce the number of respondents in a piece of research, whilst retaining as accurately as possible the characteristics of the whole group. In this blog you will read about the types and method of snowball sampling along with its advantages and disadvantages. This article explains a what quota sampling is, b how to create a quota sample, and c the advantages and. In the ambit of social research, the use of new technologies is still questioned because the selection bias is an obstacle to carry on scientific research on the internet. 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. 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.
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