Judgemental-Sampling

 

Noel S John

2048144

Judgemental Sampling

Introduction

Judgmental sampling, also called purposive sampling or authoritative sampling is a non-probability sampling technique in which the sample members are chosen only on the basis of the researcher’s knowledge and judgment. It is a type of non-probability sampling, where the samples for a study are gathered in a process that does not give all of the individuals in the population equal chances of being selected. As the researcher’s knowledge is instrumental in creating a sample in this sampling technique, there are chances that the results obtained will be highly accurate with a minimum standard of error. 

                   The process of selecting a sample using judgmental sampling involves the researchers carefully picking and choosing each individual to be a part of the sample. The researcher’s knowledge is primary in this sampling process as the members of the sample are not randomly chosen.

 

How and when to execute Judgmental Sampling?

Judgmental sampling is most effective in situations where there are only a restricted number of people in a population who own qualities that a researcher expects from the target population. Researchers prefer to implement Judgmental sampling when they feel that other sampling techniques will consume more time and that they have confidence in their knowledge to select a sample for conducting research.

It is usually used in situations where the target population comprises of highly intellectual individuals who cannot be chosen by using any other sampling technique. It is also used in situations where the sample selected using other sampling methods need to be approved or filtered. For instance, in situations where a researcher conducts convenience sampling to gather feedback from customers about a particular product of a company, but the fact that there are high chances of the results to be skewed, also with a high margin of error, the researchers prefer judgmental sampling to select those customers who will provide 100% feedback about the product.

Selecting each individual of the sample is a critical challenge that an intellectual researcher will undertake. It is a tedious task to handpick members of a sample while ensuring there is no bias involved.

The authority involved in the selection process may not necessarily be “experts” in the field but they have to comply with certain characteristics expected from a Judgmental sampling authority. Education or work experience is not considered while appointing authorities for the selection process.

Purposive sampling is used where there is a time-constraint for sample creation and the authorities involved would prefer relying on their knowledge and not on other methods of sampling. But, one must keep in mind, the fact that a researcher may or may not have the appropriate proficiency to conduct an effective sampling process. This is the only disadvantage of purposive sampling. Each researcher who takes up the responsibility of creating a sample using judgemental sampling will have to be extremely confident in their own skills and understanding of the subject.

Applications

·         A group of researchers is interested in learning if the reason why people wear eyeglasses is to read books. Common sense tells us that the efforts of the research group should be focused entirely on people that indeed wear eyeglasses. This process is judgment sampling in action. By targeting a sample comprised only of people that wear eyeglasses by using their professional judgment, researchers have a higher likelihood of achieving their research goal of learning whether or not people are wearing eyeglasses in order to read books.

 

·         Consider a scenario where a panel decides to understand what are the factors which lead a person to select online marketing as a profession. Online marketing and business is a skill which has been recently attracting youth which don’t need any special educational degrees. More and more youngsters are selecting it as a profession. The researchers who understand what are the main skills required for online marketing is will be able to decide who should form the sample to learn about it as a profession. That is when judgmental sampling is implemented. Researchers can easily filter out those participants who can be eligible to be a part of the research sample.

 

·         There are many tribes in the world which have their own religious beliefs, for instance, the Balinese people follow syncretism, which is considered to be a mixture of Hinduism and Buddhism. For researchers who plan to study the culture of Southeast Asian countries, it is advised that they select strata using judgmental sampling as religious beliefs are considered to be highly sensitive in this part of the world. Due to the sensitivity of the topic, if samples of those who have appropriate knowledge are created and research is conducted with those samples, results will be highly accurate. Probability sampling techniques often produce altered results in such cases.

 

 

Analysis of a Real-life Application of Judgemental Sampling with R codes

 

Problem: Meera wants to know what are best study methods to get through the IELTS test with high score.

Steps taken by Meera to resolve her problem:

As Meera need a precise data to solve this, she thought about making a sample by herself, so that she collected the IELTS scores of some of her seniors she knew who scored high marks in the IELTS test which was in a total of 10 marks and the data were as follows:

Here as it’s a non-probability sampling, the sample is directly chosen without having a population or the sample members are chosen only on the basis of the researcher’s knowledge and judgment.

Here, we estimated the average of the scores and their variance. Here the variance is very less and with less standard of error, which shows that the data is highly accurate as she solved her problem by judgemental sampling. Also, the average was obtained as 8.825, so it can also be inferred that she can find the best methods to study for the exam by finding people with an average score of 8.825.

Advantages:

·         Low cost required

·         A selected number of people who are known to be related to the topic is part of the study which means that there are lesser chances of having people who will distort the data.

·         Consumes minimum time for execution: In this sampling approach, the researcher expertise is important and there are no other barriers involved due to which selecting a sample becomes extremely convenient.

·         Allow researchers to approach their target market directly: There are no criteria involved in selecting a sample except for the researcher’s preferences. Due to this, he/she can communicate directly with the target the audience of their choice and produce the desired results.

·         Almost real-time results: A quick polling or survey can be conducted with the sample using judgmental sampling since the members of the sample will possess appropriate knowledge and understanding of the subject.

 

Disadvantages:

·         The sampling can be subject to the researcher’s bias: As each sample is based entirely on the judgment of the researcher, there is room for human error that results in researcher bias. 

·         The group selected may not represent all the population

·         Reliability of the data: As the sample taken is completely based on researcher’s knowledge there are instances on how reliable the data is, if the researcher doesn’t have the appropriate knowledge about the data

 

 

 

Conclusion

 

Judgment sampling may be used for a variety of reasons. In general, the goal of judgment sampling is to deliberately select units (e.g., individual people, events, objects) that are best suited to enable researchers to address their research questions. This is often done when the population of interest is very small, or desired characteristics of units are very rare, making probabilistic sampling infeasible.