What is the extent to which a research finding can be applied to a larger population?
Published on October 8, 2022 by Kassiani Nikolopoulou. Generalizability is the degree to which you can apply the results of your study to a broader context. Research
results are considered generalizable when the findings can be applied to most contexts, most people, most of the time. Do the people who agree to help you with your survey accurately represent all the people in your city? Probably not. This means that your study can’t be considered generalizable. Generalizability is determined by how representative your sample is of
the target population. This is known as external validity. The goal of research is to produce knowledge that can be applied as widely as possible. However, since it usually isn’t possible to analyze every member of a
population, researchers make do by analyzing a portion of it, making statements about that portion. To be able to apply these statements to larger groups, researchers must ensure that the sample accurately resembles the broader population. In other words, the sample and the
population must share the characteristics relevant to the research being conducted. When this happens, the sample is considered representative, and by extension, the study’s results are considered generalizable. In general, a study has good generalizability when the results
apply to many different types of people or different situations. In contrast, if the results can only be applied to a subgroup of the population or in a very specific situation, the study has poor generalizability. Why is generalizability important?Obtaining a representative sample is crucial for probability sampling. In contrast, studies using non-probability sampling designs are more concerned with investigating a few cases in depth, rather than generalizing their findings. As such, generalizability is the main difference between probability and non-probability samples. There are three factors that determine the generalizability of your study in a probability sampling design:
Increasing sample diversity can help researchers develop theories of human nature that reliably explain human behavior across countries and cultures instead of among only a thin slice of humanity. Generalizability is one of the three criteria (along with validity and reliability) that researchers use to assess the quality of both quantitative and qualitative research. However, depending on the type of research, generalizability is interpreted and evaluated differently.
Examples of generalizabilityGeneralizability is crucial for establishing the validity and reliability of your study. In most cases, a lack of generalizability significantly narrows down the scope of your research—i.e., to whom the results can be applied. Example: Narrowed scopeYou are researching the voting intentions of a small town of 3,000 residents. Due to limited time and resources, you plan to take a sample of 100 people.Luckily, you have access to an anonymized list of all residents. This allows you to establish a sampling frame and proceed with simple random sampling. With the help of an online random number generator, you draw a simple random sample. After obtaining your results (and prior to drawing any conclusions) you need to consider the generalizability of your results. Using an online sample calculator, you see that the ideal sample size is 341. With a sample of 341, you could be confident that your results are generalizable, but a sample of 100 is too small to be generalizable. This limitation of your research should be mentioned in your discussion section. However, research results that cannot be generalized can still have value. It all depends on your research objectives. Example: Non-generalizable researchSuppose you are conducting a study among visitors of the Getty Museum. You are particularly interested in how families with young children engage with a new interactive exhibit. Your goal is to advise the Getty Museum on future exhibitions geared towards families.You go to the museum for three consecutive Sundays to make observations. Your observations yield valuable insights for the Getty Museum, and perhaps even for other museums with similar educational offerings. However, you can’t claim that your findings represent all the families that visit museums in the country, or even in your city. As you collected a convenience sample, your study results are not generalizable. Nevertheless, in this case, that was not the goal of your research. Your results can still be considered valid for the context in which they were studied. Types of generalizabilityThere are two broad types of generalizability:
Statistical generalizability is critical for quantitative research. The goal of quantitative research is to develop general knowledge that applies to all the units of a population while studying only a subset of these units (sample). Statistical generalization is achieved when you study a sample that accurately mirrors characteristics of the population. The sample needs to be sufficiently large and unbiased. In qualitative research, statistical generalizability is not relevant. This is because qualitative research is primarily concerned with obtaining insights on some aspect of human experience, rather than data with solid statistical basis. By studying individual cases, researchers will try to get results that they can extend to similar cases. This is known as theoretical generalizability or transferability. How do you ensure generalizability in research?In order to apply your findings on a larger scale, you should take the following steps to ensure your research has sufficient generalizability.
After completing your research, take a moment to reflect on the generalizability of your findings. What didn’t go as planned and could impact your generalizability? For example, selection biases such as non-response bias can affect your results. Explain how generalizable your results are, as well as possible limitations, in the discussion section of your research paper. Frequently asked questions about generalizabilityCite this Scribbr articleIf you want to cite this source, you can copy and paste the citation or click the “Cite this Scribbr article” button to automatically add the citation to our free Citation Generator.
Is this article helpful?You have already voted. Thanks :-) Your vote is saved :-) Processing your vote... What are ways to make a research study generalize to the larger target population?Probability sampling procedures are considered effective to increase generalization of a study. Using a sample of participants who are representative of the population is key for making generalization from sample to population.
Can case studies be generalized to a larger population?Contrary to the prevailing view that case studies are weak in generalizability, the results of case studies can be more generalizable than those of quantitative studies in several important respects.
How can you generalize findings to a population?In order to statistically generalize the findings of a research study the sample must be randomly selected and representative of the wider population. It is important that the proportion of participants in the sample reflects the proportion of some phenomenon occurring in the population.
Which type of validity refers to the extent to which the result of a study can be generalized across time?External validity refers to the extent to which the results of a study can be generalized beyond the sample.
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