Convenience Sampling in Psychology Research

When conducting psychology research, rolling out a survey for academic purposes or collecting samples for practical scenarios, there are different approaches to doing this. One of the ways is through convenience sampling.

As the term describes, it means collecting samples from those who are the most conveniently accessible. This article provides a detailed understanding of convenience sampling, how it compares to other sampling methods, steps to conduct convenience sampling and tips on how to decide the best approach for your needs. 

Introduction to Convenience Sampling

Convenience sampling (also known as opportunity sampling or grab sampling) is one of the most common methods to get participants for surveys or research studies. It is a non-probability sampling method.

“This means that a researcher collects data from the most convenient sample available,” explains Dr. Hong-hui Lin, Clinical Psychologist, Clinical Director and Founder of The Psychology Atelier.

For instance, when you are surfing a website and are asked to take a questionnaire, you are considered a convenient sample to collect data for a survey.

Advantages of Convenience Sampling

There are some advantages of convenience sampling: 

Quick and Easy

If you have a short deadline and time is of the essence, convenience sampling can be performed quickly without much effort. Dr. Lin explains that it gives the researcher the opportunity to collect large amounts of data within a short period of time, such as through online surveys.

Suitable for Preliminary Research

Dr. Lin shared that this method provides samples that are readily available which makes it easy for researchers to test out ideas in pilot studies before launching more formal studies.

Little to No Cost

Convenience sampling is inexpensive. It can be conducted without any financial costs in some cases. A survey can be sent online which requires no travel.

Disadvantages of Convenience Sampling

The main disadvantage of convenience sampling is that the participants are not selected randomly which means that participants do not have an equal chance of being selected in the sample. 

Bias

Bias can occur using this method due to the lack of randomization. 

“The participants and information collected could be biased by a researcher’s choice of where and how to get the participants, as well as who is more inclined to volunteer or participate in a study,” explains Dr. Lin. 

Results Not Generalizable

Without randomly selected samples, some groups in the population could be over or under-represented, biasing the data collected and results. Dr. Lin advises that the results of the study will not be generalizable to the whole population and could lack credibility in the research field.

How to Conduct Convenience Sampling

Here are some steps to conduct convenience sampling:

1. Determine your research question and your target population. Who are you trying to collect data from and what type of information are you looking to understand?
2. Develop a questionnaire that helps answer your question. Consider including quantitative and qualitative questions for more insights.
3. Implement the survey through your chosen communication methods such as email, social media, in-person, mail and/or telephone.
4. Repeat the survey at different times and locations

Cases of Convenience Sampling in Various Fields

Convenience sampling is a way to collect data and it isn’t just applied in the health and clinical research field:

• You’ve probably heard of one of the most famous cases of convenience sampling in the beverage industry. The Pepsi Challenge involved setting up booths at malls, shopping centres and other public places and asking shoppers who were conveniently walking by to do a single blind taste test pitting Pepsi against Coca-Cola.
• In the hospitality industry, restaurant owners wants to understand how they are doing and what they can do better. They can reach out through their social media platforms and ask followers to complete an online survey about their experiences. Those who decide to partake are conveniently available to see the post.
• In local government, city planners often do public engagement surveys to better understand the needs of the community. They may set up tables at libraries, city halls or other public places, send emails and/or conduct cold calling to request feedback and input from their residents.

Comparison of Convenience Sampling with Other Sampling Methods

Non-probability sampling (which includes convenience sampling) and probability sampling are two main types of sampling methods. The key difference between these two methods is that one does not require randomization in selecting samples and the other does.

Non-Probability Sampling

Non-probability sampling methods refer to situations where a researcher intentionally chooses certain individuals to be in a research sample based on the research objectives.

“[I]n convenience sampling, a researcher chooses the sample based on their availability and convenience. There are not many rules to follow,” said Dr. Lin.

As randomization is not used, individuals in a population do not have an equal chance of being represented in the sample. The survey results are thus biased and cannot be generalized to the rest of the population.

Other non-probability sampling methods include the following:

• Purposive sampling: The researcher intentionally chooses participants based on their specific knowledge or background relevant to the research question 
• Referral or snowball sampling: Existing participants who are in a study are asked to recruit people they know to take part in the study. 

Probability Sampling

Probability sampling methods involve using randomization to identify individuals for a sample. Randomization may take place in different ways. 

Dr. Lin shared that the most simple version involves anonymising the population with numerical identifiers and then picking the numbers at random. 

Other methods include the following:

• Systematic sampling: Every pre-determined nth person is chosen
• Stratified sampling: Random sampling occurs within specifically identified groups. This is often performed to ensure the representation of minority groups.
• Cluster sampling: Randomly selecting groups such as schools or neighbourhoods and then randomly selecting individuals within chosen groups.

When to Use Convenience Sampling

If your research is a pilot study, in the preliminary stage of research, targets an inaccessible population and you have limited time and a lack of financial and human resources, it may be appropriate to use convenience sampling

Dr. Lin emphasized that the most important thing to do when deciding on a sampling method is to think through the rationale of your research question and then pick the most fitting sampling method to serve the purpose. 

Dr. Lin advises that in any research study/survey, the sampling method and its limitations should be made known transparently so that the results shared will not be misleading.