In quantitative studies we aim to measure variables and generalize findings obtained from a representative sample from the total population. In such studies, we will be confronted with the following questions: Is there an administrative list of the sampling frame units of the population involved?
The study population has to be clearly defined, for example, according to age, sex and residence. Apart from people, a study population may consist of villages, institutions, records, etc. Each study population consists of study units.
The way one defines the study population and the study unit depends on the problem to be investigated. If researchers want to draw conclusions that are valid for the whole study population, they should take care to draw a sample in such a way that it is representative of that population.
A representative sample is one that has all the important characteristics of the population from which it is drawn. If it is intended to interview mothers to obtain a complete picture of drug use practices in District X these mothers would need to be selected from a representative sample of villages. It would be unwise to select them from only one or two villages, as this might give a distorted or biased picture.
It would also be unwise to interview only mothers who attend the under-fives clinic, as those who do not attend this clinic may wean their children differently. An important issue influencing the choice of the most appropriate sampling method is whether a sampling frame is available, that is, a listing of all the units that compose the study population.
If a sampling frame does exist or can be compiled, probability sampling methods can be used. With these methods, each study unit has an equal or at least a known probability of being selected in the sample. This is the simplest form of probability sampling. To select a simple random sample you need to: Simple random sampling can be used for the weekly illness recall method and when selecting facilities for simulated client visits see Chapter 3.
In systematic sampling, individuals or households are chosen at regular intervals from the sampling frame. For this method we randomly select a number to tell us where to start selecting individuals from the list. For example, a systematic sample is to be selected from 1, students at a school.
The sample size selected is The sampling interval is therefore The number of the first student to be included in the sample is chosen randomly, for example, by blindly picking one out of 12 pieces of paper, numbered 1 to If number 6 is picked, then every twelfth student will be included in the sample, starting with student number 6, until students are selected.
The numbers selected would be 6, 18, 30, 42, etc. Systematic sampling is usually less time-consuming and easier to perform than simple random sampling. However, there is a risk of bias, as the sampling interval may coincide with a systematic variation in the sampling frame. For instance, if we want to select a random sample of days on which to count clinic attendance, systematic sampling with a sampling interval of 7 days would be inappropriate, as all study days would fall on the same day of the week, which might, for example, be a market day.
The simple random sampling method described above does not ensure that the proportion of some individuals with certain characteristics will be included.
If it is important that the sample includes representative groups of study units with specific characteristics for example, residents from urban and rural areas, or different age groups , then the sampling frame must be divided into groups, or strata, according to these characteristics.
Random or systematic samples of a predetermined size will then have to be obtained from each group stratum. This is called stratified sampling. Stratified sampling is only possible when we know what proportion of the study population belongs to each group we are interested in.
An advantage of stratified sampling is that it is possible to take a relatively large sample from a small group in the study population.
This makes it possible to get a sample that is big enough to enable researchers to draw valid conclusions about a relatively small group without having to collect an unnecessarily large and hence expensive sample of the other, larger groups. However, in doing so, unequal sampling fractions are used and it is important to correct for this when generalizing our findings to the whole study population.
The traditional format for grant applications places discussions of theory in the section devoted to the general significance of the research application separate from the methods and measures. However, theoretical issues and conceptual distinctions are the research tools and methods for qualitative researchers, equivalent to the quantitative researchers' standardized scales and measures.
Qualitative researchers look for the analytic refinement, rigor, and breadth in conceptualization linked to the research procedures section as signs of a strong proposal or publication. Thus basic differences in scientific emphases, complicated by expectations for standardized scientific discourse, need to be more fully acknowledged.
The logic or premises for qualitative sampling for meaning is incompletely understood in gerontology. At the same time, and partly in reaction to the dominance of the quantitative ethos, qualitative researchers have demurred from legitimating or addressing these issues in their own work. Understanding the logic behind sampling for meaning in gerontological research requires an appreciation of how it differs from other approaches.
By sampling for meaning, the authors indicate the selection of subjects in research that has as its goal the understanding of individuals' naturalistic perceptions of self, society, and the environment. Stated in another way, this is research that takes the insider's perspective. Clearly, the qualitative approach to meaning stands in marked contrast to other approaches to assessing meaning by virtue of its focus on naturalistic data and the discovery of the informant's own evaluations and categories.
For example, one approach assesses meaning by using standardized lists of predefined adjectives or phrases e. The difference between the me of that night and the me of tonight is the difference between the cadaver and the surgeon doing the cutting. Flaubert, quoted in Crapanzano , p. It is important to understand that meanings and contexts including an individual's sense of identity , the basic building blocks of qualitative research, are not fixed, constant objects with immutable traits.
Rather, meanings and identities are fluid and changeable according to the situation and the persons involved. Gustave Flaubert precisely captures the sense of active personal meaning-making and remaking across time. Cohler describes such meaning-making and remaking as the personal life history self, a self that interprets, experiences, and marshals meanings as a means to manage adversity.
A classic illustration of the fluidity of meanings is the case presented by Evans-Pritchard who explains the difficulty he had determining the names of his informants at the start of his fieldwork in Africa. He was repeatedly given entirely different names by the same people.
In the kinship-based society, the name or identity one provides to another person depends on factors relative to each person's respective clan membership, age, and community. Now known as the principle of segmentary opposition, the situated and contextual nature of identities was illustrated once the fieldworker discovered the informants were indexing their names to provide an identity at an equal level of social organization.
For example, to explain who we are when we travel outside the United States, we identify ourselves as Americans, not as someone from Oakdale Road. When we introduce ourselves to a new neighbor at a neighborhood block party, we identify ourselves by our apartment building or house on the block, not by reference to our identity as residents at the state or national level.
Themes and personal meanings are markers of processes not fixed structures. Life stories, whose narration is organized around a strongly held personal theme s as opposed to a chronology of events from birth to present day, have been linked with distress and clinical depression Luborsky b.
Williams suggests that the experience of being ill from a chronic medical disease arises when the disease disrupts the expected trajectory of one's biography. Some researchers argue that a break in the sense of continuity in personal meaning Becker , rather than any particular meaning theme , precedes illness and depression Atchley ; Antonovsky Another example of fluid meaning is ethnicity.
Ethnic identity is a set of meanings that can be fluid and vary according to the social situation, historical time period, and its personal salience over the lifetime Luborsky and Rubinstein , Ethnic identity serves as a source of fixed, basic family values during child socialization; more fluidly, as an ascribed family identity to redefine or even reject as part of psychological processes of individuation in early adulthood; sometimes a source of social stigma in communities or in times of war with foreign countries e.
From the qualitative perspective, there are a number of contrasts that emerge between sampling for meaning and more traditional, survey-style sampling, which has different goals. Those who are not familiar with the sampling-for-meaning approach often voice concerns over such aspects as size Lieberson , adequacy and, most tellingly, purpose of the sampling.
Why, for example, are sample sizes often relatively small? What is elicited and why? What is the relationship between meanings and other traditional categories of analyses, such as age, sex, class, social statuses, or particular diseases? What is perhaps the most important contrast between the sampling-for-meaning approach and more standard survey sampling is found in the model of the person that underlies elicitation strategies.
From this perspective, individuals are viewed as sets of fixed traits and not as carriers and makers of meaning. Sampling for meaning, in contrast, is based on four very distinct notions.
The first is that responses have contexts and carry referential meaning. Thus questions about events, activities, or other categories of experience cannot be understood without some consideration of how these events implicate other similar or contrasting events in a person's life Scheer and Luborsky This is particularly important for older people.
Second, individuals often actively interpret experience. That is to say, many people—but not all—actively work to consider their experience, put it in context, and understand it. Experience is not a fixed response. Further, the concern with meanings or of remaking meaning can be more emergent during some life stages and events or attention to certain kinds of meanings than others.
Examples of this include bereavement, retirement, ethnic identity, and personal life themes in later life. Third, certain categories of data do not have a separable existence apart from their occurrences embodied within routines and habits of the day and the body. Consequently, qualitative research provides a context and facilitates a process of collaboration between researcher and informant.
Fourth, interpretation, either as natural for the informant or facilitated in the research interview, is basically an action of interpretation of experience that makes reference to both sociocultural standards, be they general cultural standards or local community ones, as well as the ongoing template or matrix of individual experience.
Thus, for example, a person knows cultural ideals about a marriage, has some knowledge of other people's marriages, and has intimate knowledge of one's own. In the process of interpretation, all these levels come into play. These issues occur over a variety of sampling frames and processing frameworks. There are three such sampling contexts. First, sampling for meaning occurs in relation to individuals as representatives of experiential types.
Here, the goal is the elucidation of particular types of meaning or experience personal, setting-based, sociocultural , through inquiry about, discussion of, and conversation concerning experiences and the interpretation of events and social occur-rences.
The goal of sampling, in this case, is to produce collections of individuals from whom the nature of experience can be elicited through verbal descriptions and narrations. Second, sampling for meaning can occur in the context of an individual in a defined social process. An example here could include understanding the entry of a person into a medical practice as a patient, for the treatment of a disorder.
Qualitatively, we might wish to follow this person as she moves through medical channels, following referrals, tests, and the like. Even beginning this research at a single primary physician, or with a sample of individuals who have a certain disorder, the structure of passage through a processing system may vary widely and complexly.
However, given a fixed point of entry a medical practice or a single disease , sampling for meaning is nested in ongoing social processes. Researchers wish to understand not only the patient's experience of this setting as she moves through it e. Finally, researchers may wish to consider sampling for meaning in a fixed social setting. An example might be a nursing home unit, with a more or less fixed number of residents, some stability but some change, and regular staff of several types representing distinctive organizational strata and interests administration, medicine, nursing, social work, aides, volunteers, family, or environmental services.
It is important to note that even though qualitative research focuses on the individual, subjectivity or individuality is not the only goal of study. Qualitative research can focus on the macrolevel. One basic goal of qualitative research in aging is to describe the contents of people's experiences of life, health, and disability. It is true that much of the research to date treats the individual as the basic unit of analysis.
Yet, the development of insights into the cultural construction of life experiences is an equal priority because cultural beliefs and values instill and shape powerful experiences, ideals, and motivations and shape how individuals make sense of and respond to events. Studying how macrolevel cultural and community ideologies pattern the microlevel of individual life is part of a tradition stretching from Margaret Mead, Max Weber, Robert Merton, Talcott Parsons, to studies of physical and mental disabilities by Edgerton , Esteroff , and Murphy For example, Stouffer's pioneering of survey methods revealed that American soldiers in World War II responded to the shared adversity of combat differently according to personal expectations based on sociocultural value patterns and lived experiences.
These findings further illustrate Merton's theories of relative deprivation and reference groups, which point to the basis of individual well-being in basic processes of social comparison. The notion of stigma illustrates the micro- and the macrolevels of analyses. For example, stigma theory's long reign in the social and political sciences and in clinical practice illustrates the micro- and macroqualitative perspectives.
Stigma theory posits that individuals are socially marked or stigmatized by negative cultural evaluations because of visible differences or deformities, as defined by the community. Patterns of avoidance and denial of the disabled mark the socially conditioned feelings of revulsion, fear, or contagion. Personal experiences of low self-esteem result when negative messages are internalized by, for example, persons with visible impairments, or the elderly in an ageist setting. Management of social stigma by individuals and family is as much a focus as is management of impairments.
Stigma is related significantly to compliance with prescribed adaptive devices Zola ; Luborsky a. A graphic case of this phenomenon are polio survivors who were homebound due to dependence on massive bedside artificial ventilators. With the recent advent of portable ventilators, polio survivors gained the opportunity to become mobile and travel outside the home, but they did not adopt the new equipment, because the new independence was far outweighed by the public stigma they experienced Kaufert and Locker A final point is that sampling for meaning can also be examined in terms of sampling within the data collected.
For example, the entire corpus of materials and observations with informants needs to be examined in the discovery and interpretive processes aimed at describing relevant units for analyses and dimensions of meaning. This is in contrast to reading the texts to describe and confirm a finding without then systematically rereading the texts for sections that may provide alternative or contradictory interpretations.
As discussed earlier, probability sampling techniques cannot be used for qualitative research by definition, because the members of the universe to be sampled are not known a priori, so it is not possible to draw elements for study in proportion to an as yet unknown distribution in the universe sampled. A review of the few qualitative research publications that treat sampling issues at greater length e. A consensus among these authors is found in the paramount importance they assign to theory to guide the design and selection of samples Platt These are briefly reviewed as follows.
First, convenience or opportunistic sampling is a technique that uses an open period of recruitment that continues until a set number of subjects, events, or institutions are enrolled.
Here, selection is based on a first-come, first-served basis. This approach is used in studies drawing on predefined populations such as participants in support groups or medical clinics. Second, purposive sampling is a practice where subjects are intentionally selected to represent some explicit predefined traits or conditions. This is analogous to stratified samples in probability-based approaches. The goal here is to provide for relatively equal numbers of different elements or people to enable exploration and description of the conditions and meanings occurring within each of the study conditions.
The objective, however, is not to determine prevalence, incidence, or causes. Third, snowballing or word-of-mouth techniques make use of participants as referral sources.
Participants recommend others they know who may be eligible. Fourth, quota sampling is a method for selecting numbers of subjects to represent the conditions to be studied rather than to represent the proportion of people in the universe. The goal of quota sampling is to assure inclusion of people who may be underrepresented by convenience or purposeful sampling techniques. Fifth, case study Ragin and Becker ; Patton samples select a single individual, institution, or event as the total universe.
A variant is the key-informant approach Spradley , or intensity sampling Patton where a subject who is expert in the topic of study serves to provide expert information on the specialized topic. When qualitative perspectives are sought as part of clinical or survey studies, the purposive, quota, or case study sampling techniques are generally the most useful.
How many subjects is the perennial question. There is seldom a simple answer to the question of sample or cell size in qualitative research. There is no single formula or criterion to use. The question of sample size cannot be determined by prior knowledge of effect sizes, numbers of variables, or numbers of analyses—these will be reported as findings. Sample sizes in qualitative studies can only be set by reference to the specific aims and the methods of study, not in the abstract.
The answer only emerges within a framework of clearly stated aims, methods, and goals and is conditioned by the availability of staff and economic resources. In practice, from 12 to 26 people in each study cell seems just about right to most authors. In general, it should be noted that Americans have a propensity to define bigger as better and smaller as inferior.
Quantitative researchers, in common with the general population, question such small sample sizes because they are habituated to opinion polls or epidemiology surveys based on hundreds or thousands of subjects. However, sample sizes of less than 10 are common in many quantitative clinical and medical studies where statistical power analyses are provided based on the existence of very large effect sizes for the experimental versus control conditions.
Other considerations in evaluating sample sizes are the resources, times, and reporting requirements. In anthropological field research, a customary formula is that of the one to seven: Thus, in studies that use more than one interviewer, the ability to collect data also increases the burden for analyses.
An outstanding volume exploring the logic, contributions, and dilemmas of case study research Ragin and Becker reports that survey researchers resort to case examples to explain ambiguities in their data, whereas qualitative researchers reach for descriptive statistics when they do not have a clear explanation for their observations.
Again, the choice of sample size and group design is guided by the qualitative goal of describing the nature and contents of cultural, social, and personal values and experiences within specific conditions or circumstances, rather than of determining incidence and prevalence. In the tradition of informant-based and of participatory research, it is assumed that all members of a community can provide useful information about the values, beliefs, or practices in question. Experts provide detailed, specialized information, whereas nonexperts do so about daily life.
In some cases, the choice is obvious, dictated by the topic of study, for example, childless elderly, retirees, people with chronic diseases or new disabilities. In other cases, it is less obvious, as in studies of disease, for example, that require insights from sufferers but also from people not suffering to gain an understanding for comparison with the experiences and personal meanings of similar people without the condition. Comparisons can be either on a group basis or matched more closely on a one-to-one basis for many traits e.
However, given the labor-intensive nature of qualitative work, sometimes the rationale for including control groups of people who do not have the experiences is not justifiable. Currently, when constructing samples for single study groups, qualitative research appears to be about equally split in terms of seeking homogeneity or diversity. There is little debate or attention to these contrasting approaches. For example, some argue that it is more important to represent a wide range of different types of people and experiences in order to represent the similarities and diversity in human experience, beliefs, and conditions e.
In contrast, others select informants to be relatively homogeneous on several characteristics to strengthen comparability within the sample as an aid to identifying similarities and diversity. To review, the authors suggest that explicit objective criteria to use for evaluating qualitative research designs do exist, but many of these focus on different issues and aspects of the research process, in comparison to issues for quantitative studies.
This article has discussed the guiding principles, features, and practices of sampling in qualitative research. The guiding rationale is that of the discovery of the insider's view of cultural and personal meanings and experience.
Major features of sampling in qualitative research concern the issues of identifying the scope of the universe for sampling and the discovery of valid units for analyses. The practices of sampling, in comparison to quantitative research, are rooted in the application of multiple conceptual perspectives and interpretive stances to data collection and analyses that allow the development and evaluation of a multitude of meanings and experiences.
This article noted that sampling concerns are widespread in American culture rather than in the esoteric specialized concern of scientific endeavors Luborsky and Sankar Core scientific research principles are also basic cultural ideals Luborsky Knowledge about the rudimentary principles of research sampling is widespread outside of the research laboratory, particularly with the relatively new popularity of economic, political, and community polls as a staple of news reporting and political process in democratic governance.
Core questions about the size, sources, and features of participants are applied to construct research populations, courtroom juries, and districts to serve as electoral universes for politicians. The cultural contexts and popular notions about sampling and sample size have an impact on scientific judgments.
It is important to acknowledge the presence and influence of generalized social sensibilities or awareness about sampling issues. Such notions may have less direct impact on research in fields with long-established and formalized criteria and procedures for determining sample size and composition.
The generalized social notions may come to exert a greater influence as one moves across the spectrum of knowledge-building strategies to more qualitative and humanistic approaches. Even though such studies also have a long history of clearly articulated traditions of formal critiques e.
The authors suggested that some of the rancor between qualitative and quantitative approaches is rooted in deeper cultural tensions. Prototypic questions posed to qualitative research in interdisciplinary settings derive from both the application of frameworks derived from other disciplines' approaches to sampling as well as those of the reviewers as persons socialized into the community where the study is conceived and conducted.
Such concerns may be irrelevant or even counterproductive. The guiding logic of qualitative research, by design, generally prevents it from being able to fulfill the assumptions underlying statistical power analyses of research designs. The discovery-oriented goals, use of meanings as units of analyses, and interpretive methods of qualitative research dictate that the exact factors, dimensions, and distribution of phenomena identified as important for analyses may not always be specified prior to data analyses activities.
These emerge from the data analyses and are one of the major contributions of qualitative study. No standardized scales or tests exist yet to identify and describe new arenas of cultural, social, or personal meanings. Meaning does not conform to normative distributions by known factors.
No probability models exist that would enable prediction of distributions of meanings needed to perform statistical power analyses. Qualitative studies however can, and should, be judged in terms of how well they meet the explicit goals and purposes relevant to such research.
The authors have suggested that the concept of qualitative clarity be developed to guide evaluations of sampling as an analog to the concept of statistical power.
Qualitative clarity refers to principles that are relevant to the concerns of this type of research.
That is, the adequacy of the strength and flexibility of the analytic tools used to develop knowledge during discovery procedures and interpretation can be evaluated even if the factors to be measured cannot be specified. The term clarity conveys the aim of making explicit, for open discussion, the details of how the sample was assembled, the theoretical assumptions and the pragmatic constraints that influenced the sampling process. These are briefly described next. In the absence of standardized measures for assessing meaning, the analogous qualitative research tools are theory and discovery processes.
Strong and well-developed theoretical preparation is necessary to provide multiple and alternative interpretations of the data. The relative degree of theoretical development in a research proposal or manuscript is readily apparent in the text, for example, in terms of extended descriptions of different schools of thought and possible multiple contrasting of interpretive explanations for phenomena at hand.
In brief, the authors argue that given the stated goal of sampling for meaning, qualitative research can be evaluated to assess if it has adequate numbers of conceptual perspectives that will enable the study to identify a variety of meanings and to critique multiple rich interpretations of the meanings.
Sampling within the data is another important design feature. The discovery of meaning should also include sampling within the data collected. The entire set of qualitative materials should be examined rather than selectively read after identifying certain parts of the text to describe and confirm a finding without reading for sections that may provide alternative or contradictory interpretations. As a second component of qualitative clarity, sensitivity to context refers to the contextual dimensions shaping the meanings studied.
It also refers to the historical settings of the scientific concepts used to frame the research questions and the methods. Researchers need to be continually attentive to examining the meanings and categories discovered for elements from the researchers' own cultural and personal backgrounds.
The first of these contexts is familiar to gerontologists: Another more implicit contextual aspect to examine as part of the qualitative clarity analysis is evidence of a critical view of the methods and theories introduced by the investigators. Because discovery of the insiders' perspective on cultural and personal meanings is a goal of qualitative study, it is important to keep an eye to biases derived from the intrusion of the researcher's own scientific categories.
Qualitative research requires a critical stance as to both the kinds of information and the meanings discovered, and to the analytic categories guiding the interpretations. One example is recent work that illustrates how traditional gerontological constructs for data collection and analyses do not correspond to the ways individuals themselves interpret their own activities, conditions, or label their identities e. A second example is the growing awareness of the extent to which past research tended to define problems of disability or depression narrowly in terms of the individual's ability, or failure, to adjust, without giving adequate attention to the societal level sources of the individual's distress Cohen and Sokolovsky Thus researchers need to demonstrate an awareness of how the particular questions guiding qualitative research, the methods and styles of analyses, are influenced by cultural and historical settings of the research Luborsky and Sankar in order to keep clear whose meanings are being reported.
To conclude, our outline for the concept of qualitative clarity, which is intended to serve as the qualitatively appropriate analog to statistical power, is offered to gerontologists as a summary of the main points that need to be considered when evaluating samples for qualitative research. The descriptions of qualitative sampling in this article are meant to extend the discussion and to encourage the continued development of more explicit methods for qualitative research.
Ongoing support for the second author from the National Institute of Aging is also gratefully acknowledged. Federal and foundation grants support his studies of sociocultural values and personal meanings in early and late adulthood, and how these relate to mental and physical health, and to disability and rehabilitation processes.
He also consults and teaches on these topics. His gerontological research interests include social relations of the elderly, childlessness in later life, and the home environments of old people.
National Center for Biotechnology Information , U. Author manuscript; available in PMC Nov 3. The publisher's final edited version of this article is available at Res Aging.
See other articles in PMC that cite the published article. Abstract In gerontology the most recognized and elaborate discourse about sampling is generally thought to be in quantitative research associated with survey research and medical research. Contributions, Logic and Issues in Qualitative Sampling Major contributions Attention to sampling issues has usually been at the heart of anthropology and of qualitative research since their inception.
Ideals and Techniques of Qualitative Sampling The preceding discussion highlighted the need to first identify the ideal or goal for sampling and second to examine the techniques and dilemmas for achieving the ideal. Core ideals include the determination of the scope of the universe for study and the identification of appropriate analytic units when sampling for meaning Defining the universe This is simultaneously one of qualitative research's greatest contributions and greatest stumbling blocks to wider acceptance in the scientific community.
Sampling for meaning The logic or premises for qualitative sampling for meaning is incompletely understood in gerontology. Techniques for selecting a sample As discussed earlier, probability sampling techniques cannot be used for qualitative research by definition, because the members of the universe to be sampled are not known a priori, so it is not possible to draw elements for study in proportion to an as yet unknown distribution in the universe sampled.
Who and who not? Homogeneity or diversity Currently, when constructing samples for single study groups, qualitative research appears to be about equally split in terms of seeking homogeneity or diversity. Summary and Reformulation for Practice To review, the authors suggest that explicit objective criteria to use for evaluating qualitative research designs do exist, but many of these focus on different issues and aspects of the research process, in comparison to issues for quantitative studies.
Qualitative Clarity as an Analog to Statistical Power The guiding logic of qualitative research, by design, generally prevents it from being able to fulfill the assumptions underlying statistical power analyses of research designs. Rich and diverse theoretical grounding In the absence of standardized measures for assessing meaning, the analogous qualitative research tools are theory and discovery processes.
Sensitivity to contexts As a second component of qualitative clarity, sensitivity to context refers to the contextual dimensions shaping the meanings studied. Who Cares for the Elderly.
Temple University Press; Philadelphia: A Path Not Taken: Unraveling the Mystery of Health. A Continuity Theory of Aging. Continuity After a Stroke: Family and Social Networks. Cohen Carl, Sokolovsky Jay.
Sampling and types of sampling methods commonly used in quantitative research are discussed in the following module. Learning Objectives: Define sampling and randomization. Explain probability and non-probability sampling and describes the different types of each.
Probability sampling methods for quantitative studies In quantitative studies we aim to measure variables and generalize findings obtained from a representative sample from the total population. In such studies, we will be confronted with the following questions. Quantitative Research Definition: Quantitative research, in marketing, is a stimulating and highly educational technique to gather information from existing and potential customers using sampling methods and sending out online surveys, online polls, questionnaires etc., the results of which can be.
experimental, quasi-experimental, and non-experimental quantitative research designs, Now it is time to deal with two more important aspects of quantitative reserach design: sampling, and. measurement. Key Terms. Sampling. sampling. sampling frame. of different sampling methods . Chapter 8: Quantitative Sampling I. Introduction to Sampling or reputational sampling) is a method for identifying and sampling the cases in a network. It begins with one is a special sampling technique used in research projects in which the general public is interviewed by telephone. Here is how RDD works in the United States.