Sampling methods in marketing research pdf

Whilst in this example the bias is obvious and should be easily corrected, this may not always be the case. It is used when we might reasonably expect the measurement of interest to vary between the different subgroups, and we want to ensure representation from all the subgroups.

For example, in a study of stroke outcomes, we may stratify the population by sex, to ensure equal representation of men and women. The study sample is then obtained by taking equal sample sizes from each stratum. In stratified sampling, it may also be appropriate to choose non-equal sample sizes from each stratum.

This ensures a more realistic and accurate estimation of the health outcomes of nurses across the county, whereas simple random sampling would over- represent nurses from hospitals A and B. The fact that the sample was stratified should be taken into account at the analysis stage. However, it requires knowledge of the appropriate characteristics of the sampling frame the details of which are not always available , and it can be difficult to decide which characteristic s to stratify by.

The population is divided into subgroups, known as clusters, which are randomly selected to be included in the study. Clusters are usually already defined, for example individual GP practices or towns could be identified as clusters.

In single-stage cluster sampling, all members of the chosen clusters are then included in the study. In two-stage cluster sampling, a selection of individuals from each cluster is then randomly selected for inclusion. Clustering should be taken into account in the analysis. The General Household survey, which is undertaken annually in England, is a good example of a one-stage cluster sample.

All members of the selected households clusters are included in the survey. For instance, it is easier to contact lots of individuals in a few GP practices than a few individuals in many different GP practices.

Disadvantages include an increased risk of bias, if the chosen clusters are not representative of the population, resulting in an increased sampling error. Useful results can be obtained, but the results are prone to significant bias, because those who volunteer to take part may be different from those who choose not to volunteer bias , and the sample may not be representative of other characteristics, such as age or sex. Note: volunteer bias is a risk of all non-probability sampling methods.

Quota sampling. Interviewers are given a quota of subjects of a specified type to attempt to recruit. For example, an interviewer might be told to go out and select 20 adult men, 20 adult women, 10 teenage girls and 10 teenage boys so that they could interview them about their television viewing. Ideally the quotas chosen would proportionally represent the characteristics of the underlying population.

This approach is often used by the media when canvassing the public for opinions and in qualitative research. However, in addition to volunteer bias, it is also prone to errors of judgement by the researcher and the findings, whilst being potentially broad, will not necessarily be representative.

Existing subjects are asked to nominate further subjects known to them, so the sample increases in size like a rolling snowball. For example, when carrying out a survey of risk behaviours amongst intravenous drug users, participants may be asked to nominate other users to be interviewed. However, by selecting friends and acquaintances of subjects already investigated, there is a significant risk of selection bias choosing a large number of people with similar characteristics or views to the initial individual identified.

Fieldwork What is Field Research? Field research is defined as a qualitative method of data collection that aims to observe, interact and understand people while they are in a natural environment. For example, nature conservationists observe behavior of animals in their natural surroundings and the way they react to certain scenarios.

In the same way, social scientists conducting field research may conduct interviews or observe people from a distance to understand how they behave in a social environment and how they react to situations around them.

Field research encompasses a diverse range of social research methods including direct observation, limited participation, analysis of documents and other information, informal interviews, surveys etc. Although field research is generally characterized as qualitative research, it often involves multiple aspects of quantitative research in it.

Field research typically begins in a specific setting although the end objective of the study is to observe and analyze the specific behavior of a subject in that setting. The cause and effect of a certain behavior, though, is tough to analyze due to presence of multiple variables in a natural environment. Most of the data collection is based not entirely on cause and effect but mostly on correlation.

While field research looks for correlation, the small sample size makes it difficult to establish a causal relationship between two or more variables. Methods of Field Research. In this method, the data is collected via an observational method or subjects in a natural environment. In this method, the behavior or outcome of situation is not interfered in any way by the researcher. The advantage of direct observation is that it offers contextual data on people, situations, interactions and the surroundings.

This method of field research is widely used in a public setting or environment but not in a private environment as it raises an ethical dilemma. Participant Observation In this method of field research, the researcher is deeply involved in the research process, not just purely as an observer, but also as a participant. This method too is conducted in a natural environment but the only difference is the researcher gets involved in the discussions and can mould the direction of the discussions.

In this method, researchers live in a comfortable environment with the participants of the research, to make them comfortable and open up to in-depth discussions.

Ethnography Ethnography is an expanded observation of social research and social perspective and the cultural values of an entire social setting. In ethnography, entire communities are observed objectively. Qualitative Interviews.

Qualitative interviews are close-ended questions that are asked directly to the research subjects. The qualitative interviews could be either informal and conversational, semi-structured, standardized and open- ended or a mix of all the above three. This provides a wealth of data to the researcher that they can sort through.

This also helps collect relational data. This method of field research can use a mix of one-on- one interviews, focus groups and text analysis. Case Study A case study research is an in-depth analysis of a person, situation or event.

This method may look difficult to operate, however, it is one of the simplest ways of conducting research as it involves a deep dive and thorough understanding the data collection methods and inferring the data. Steps in Conducting Field Research. The role of the researcher and any ancillary team members is very important and defining the tasks they have to carry out with defined relevant milestones is important.

It is important that the upper management too is vested in the field research for its success. Using sampling methods, it is important to derive the people that will be a part of the study. They could be a mix of surveys, interviews, case studies and observation. All these methods have to be chalked out and the milestones for each method too have to be chalked out at the outset.

For example, in the case of a survey, the survey design is important that it is created and tested even before the research begins. Hence, planning a site visit alongwith the methods of data collection is important. Open navigation menu. Close suggestions Search Search.

User Settings. Skip carousel. Carousel Previous. Carousel Next. What is Scribd? Explore Ebooks. Bestsellers Editors' Picks All Ebooks. Explore Audiobooks. Bestsellers Editors' Picks All audiobooks. Explore Magazines. Editors' Picks All magazines. Explore Podcasts All podcasts. Difficulty Beginner Intermediate Advanced. Explore Documents.

Did you find this document useful? Is this content inappropriate? Report this Document. Flag for inappropriate content. Related titles. Carousel Previous Carousel Next. Jump to Page. Search inside document. Qualitative Interviews Qualitative interviews are close-ended questions that are asked directly to the research subjects. Fahmi Taher. Wao Eric Wamola. Alfred Rentuza. Jayson Lucas. Ayush Puri. Alpher Hope Medina. Christine Suratos. Jordz Placi. Syiva Nur Latifah.

Eunice Dimple Caliwag. Ayesha Usman. Dela Stefani. Shivam Jadhav. Sherlock Holmes. Thinje Flor. Swapnil Maurya. Ezenwafor Evans. Qu Scarlett. Konstantin Malkov. Ujjwal DMFE. Popular in Technology. Selvaraj Simiyon. Sheik Shafi. Nurarief Affendy. Gabriel Blanco Herrera. Ranndolf Javier. Giancarlo Lavado. Louis households could be broken down into strata such as those living in single family owned homes, single family rental units, multi-family housing, etc.

The systematic sampling method is then started to ensure the final sample pool adequately represents each strata. Quota sampling is a technique which takes stratified sampling to greater detail by requiring quotas to be reached within each of the strata.

In this way, it is a non-probabilistic version of stratified sampling. The downside to quota sampling is that with an inadequate sample pool, quota sampling can force a hand-picking of participants which gives an opening for bias.

Also, as the selection is no longer random, the margin of error cannot be calculated. When a large population, especially one over a wide geographic area, needs to be sampled, cluster sampling can be a good option. In research design, the population of study is broken down into smaller groups, referred to as clusters.

Individuals are then selected randomly from the clusters to create the study sample. Example: Five large St. Louis neighborhoods are selected as clusters and individuals are selected randomly from each cluster to represent opinions from every neighborhood in the city more accurately.

A large number of small clusters to sample from is preferred to a small number of large clusters. This is best practice is used to eliminate cluster sampling bias CSB which can occur when some clusters in a given territory are more likely to be sampled than others.

Area sampling is a random sampling technique applied with geographic boundaries. Area sampling is a common technique used for ecological or geographic sampling. It is not often used in the study of humans or human behavior as the potential to end up in areas with no observational instances, such as a desert, or sparsely populated area is possible.

If area sampling is used to observe humans, selecting random areas within a known populated region can ameliorate these issues by combining some standards of cluster sampling with this technique. Before choosing a sampling technique for any study, the objectives and measurement protocols should be determined. The goals of the study, the available resources and the amount of time allotted for study completion and analysis are factors that may immediately eliminate some techniques and guide the decision for the best possible outcome.

Once the sampling type is confirmed, screening potential participants begins. This free guide offers an easy-to-follow and comprehensive resource for getting started. Topics: research design. Market Research Blog. Updates from CFR. True Random Sampling True random sampling is the gold standard for probabilistic studies, but it may not be attainable with certain limitations.

Systematic Sampling Systematic sampling is the more common cousin of true random sampling. Stratified Sampling A modified approach to systematic sampling is called stratified sampling. Quota Sampling Quota sampling is a technique which takes stratified sampling to greater detail by requiring quotas to be reached within each of the strata.

Cluster Sampling When a large population, especially one over a wide geographic area, needs to be sampled, cluster sampling can be a good option. Area Sampling Area sampling is a random sampling technique applied with geographic boundaries.