Open in a separate window Embedded in each strategy is the ability to compare and contrast, to identify similarities and differences in the phenomenon of interest.
Typical Case Sampling 3.
A sample is representative when it allows the results of the sample to be generalized to the population. Point out that the obvious disadvantage of convenience sampling is that it is likely to be biased [ 13 ].
To test the whole population, the researcher would need all current university students and hence, a lot of time, energy and resources. However, by population, many often consider to people only.
Following is a discussion of probability and non-probability sampling and the different types of each. You can get an idea about which groups to select by reviewing your problem analysis diagram.
One of the major benefits of purposive sampling is the wide range of sampling techniques that can be used across such qualitative research designs; purposive sampling techniques that range from homogeneous sampling through to critical case sampling, expert sampling, and more.
By conducting semi-structured interviews with both groups and comparing findings you can get an idea of the reasons for appropriate and inappropriate practices.
Although, Nonprobability sampling has a lot of limitations due to the subjective nature in choosing the sample and thus it is not good representative of the population, but it is useful especially when randomization is impossible like when the population is very large.
Maximum Variation Sampling The idea behind MVS is to look at a subject from all available angles, thereby achieving a greater understanding. Students in those preschools could then be selected at random through a systematic method to participate in the study.
This is more convenient than taking a random sample of people in the village and it gives a useful first impression.
In fact, the researcher does not know how well a convenience sample will represent the population regarding the traits or mechanism under research.
Criterion-i sampling was most frequently used in mixed methods implementation studies that employed a simultaneous design where the qualitative method was secondary to the quantitative method or studies that employed a simultaneous structure where the qualitative and quantitative methods were assigned equal priority.
For example, my population of interest may be adolescent females in the United States. Convenience sampling also known as Haphazard Sampling or Accidental Sampling is a type of nonprobability or nonrandom sampling where members of the target population that meet certain practical criteria, such as easy accessibility, geographical proximity, availability at a given time, or the willingness to participate are included for the purpose of the study [ 4 ].
Disadvantages of purposive sampling Purposive samples, irrespective of the type of purposive sampling used, can be highly prone to researcher bias. If that group is having problems, then we can be sure all the groups are having problems? The population refers to the set of individual units which the research question seeks to find out about.
For example, if I use as my sampling frame the lists of students held by public and private schools in America from which to select a sample of adolescent females, then only students on those lists have a real chance of being selected.
Sampling for focus group discussions The main decision you need to take when planning focus group discussions is what focus you intend to have, and how many FGDs you intend to hold. Purposive sampling is useful in these instances because it provides a wide range of non-probability sampling techniques for the researcher to draw on.
Hence, there is a risk of collecting poor quality data due to poor research outcomes and as such, difficult to convince others to accept the findings of research based on poor foundation [ 16 ]. Within each group the informants should be relatively homogenous in terms of the important dimensions of the study; but for the different groups you select contrasting cases for example, men and women; younger and older; users and non users.
Sampling Methods for Quantitative Research Sampling Methods Sampling and types of sampling methods commonly used in quantitative research are discussed in the following module.
The idea that a purposive sample has been created based on the judgement of the researcher is not a good defence when it comes to alleviating possible researcher biases, especially when compared with probability sampling techniques that are designed to reduce such biases.
In some situations, the population may not be well defined. The main objective of convenience sampling is to collect information from participants who are easily accessible to the researcher like recruiting providers attending a staff meeting for study participation.
The group of units or individuals who have a legitimate chance of being selected are sometimes referred to as the sampling frame. If you wanted to study information provision on medicines in pharmacies, you could observe all client-drug-seller interactions during one particular day.
So, for example, two with men and two with women, or two with adults and two with adolescents.Ethnobotany Research & Applications () Ma.
Dolores C. Tongco, Department of Botany, University of The purposive sampling technique also be used with both qualitative and quantitative re-search techniques. The inherent bias of the method con-tributes to its efficiency, and the method stays robust even when. Different articles were reviewed to compare between Convenience Sampling and Purposive Sampling and it is concluded that the choice of the techniques (Convenience Sampling and Purposive Sampling) depends on the nature and type of the research.
Yes, you still can do the puposive sampling for quantitative analysis. In quantitaive analysis, you have two techniques such as parametric and non-parametric techniques involved.
Basically, probability sampling is suit to parametric tecnique since the this application need normality data for an analysis. Purposeful sampling for qualitative studies There are several strategies for purposeful sampling of information-rich cases. The methods most commonly used in qualitative studies are given here, including the purpose for which the method is especially useful and its disadvantages.
Chapter 8: Quantitative Sampling I. Introduction to Sampling Quantitative researchers tend to use a type of Purposive sampling is an acceptable kind of sampling for special situations.
It uses the judgment of an expert in selecting cases or it selects cases with a specific. In the practical exercise (Quantitative Exam Task 1 - 5%) you developed three quantitative research designs (experimental, quasi-experimental, and non-experimental) for your research question, and considered the strengths and weaknesses, as well as practical issues, for each of these designs.Download