Exploring Validity and Reliability in Survey Research (2024)

Reliability and validity are both concepts used to evaluate the quality of research. Reliability reflects the extent to which the results of the research can be reproduced when repeated under the same conditions. Validity reflects the degree to which the results of a research measure what the study was meant to measure.

It is often quite a tedious task to obtain accurate, reliable, and valid assessments of public opinion. When creating surveys using survey software, it is important to have an understanding of the subtle relationships between questions, and how these relationships can influence how the questions are perceived by respondents. It is also important to understand the techniques using which questions can be produced to be reliable and valid.

In this blog, we’ll explore the various concepts and methods one must keep in mind while designing public opinion questionnaires to ensure that they are reliable and valid.

Psychometrics literature outline two key types of reliability, each with a different kind of consistency in responses:

• • Consistency in Responding Over Time
  • Consistency in Responding to Similar Questions

Reliability as Consistency in Responding Over Time

Consistency in responding across time, also known as test-retest reliability, is evaluated by observing the degree of association between responses at two different time points. If respondents are asked the same question at different time points and the correlation is 0.9, that would indicate temporal stability and reflects that the survey has good test-retest reliability.

Reliability as Consistency in Responding to Similar Questions

The second type of reliability-related consistency is known as internal consistency and refers to the consistency in responding across similar items. It is measured using a statistic known as alpha (α), which is the percentage of variance in an unmeasured variable that is measured by the shared variation between component items. If α (the reliability coefficient) is 0.8, for instance, this would indicate a variance of 80%.

When exploring validity in research, we will look at it from two different perspectives:

• A Psychometrics Perspective
• A Survey Research Methods Perspective

Validity from a Psychometrics Perspective

From this perspective, validity focuses on how explicitly a survey question can be linked to the researcher’s purpose for conducting the study. For a valid questionnaire to be developed, questions must be clear, specific, and concrete so as to obtain responses that allow the researcher to meet their goal.

Validity from a Survey Research Methods Perspective

Survey methodologists are concerned with the validity of questionnaires from a different perspective. Their focus is on the subject of the survey so that clear and unambiguous questions can be created. There are three basic principles that compose the design of survey questions:

• The researcher must have a deeper awareness of the research topic and must develop the research idea in a systematic and logical way before the survey is created using a market research software.
• The questions must be clear and unambiguous and must reflect the research idea.
• The survey must be pretested to ensure the questions are clear, unambiguous, and are clearly linked to the research idea.

In this section, we will look into different approaches to achieve reliability and validity in the survey. We will start with achieving reliability.

2 ways to test survey reliability

1. Test-retest reliability.
2. Internal reliability.

Let’s look into these two types of survey reliability approaches.

1. Test-retest reliability:

The test-retest process indicates that you administer the same survey to the same group of respondents at different points in time. If the responses you receive are consistent across time, it will serve as proof of reliability.

2. Interrater reliability:

This test helps you measure the degree of agreement between different people evaluating the same subject.

To perform this test, you can have different researchers conduct the same survey on the same group of respondents. By comparing the different results, you can measure the correlation. If the different researchers give similar results, it indicates the survey has high interrater reliability.

1. Content validity
2. Internal validity
3. External validity
4. Construct validity
5. Criterion-related validity

Let’s look into the 5 types of survey validity approaches.

1. Content validity:

To achieve validity in survey research, ensure that your questions cover all the relevant topics of the objective. Pilot testing and expert review can help you assess content validity while it, in turn, helps you gather reliable data.

2. Internal validity:

With this test, you can ensure that the survey questions properly explain the outcome of the research. For example, say you want to identify factors that influence a customer’s decision to buy a sofa. Here you will look for the relation between independent variables, like replacing an old sofa or buying a new one, and the dependent variable, i.e., the likelihood of buying a sofa.

3. External validity:

This test helps you understand the extent to which you can generalize the result to the target population. The questions you ask should gather data that represents how the target audience thinks about the research objective.

4. Construct validity:

It evaluates whether the survey method represents and measures the construct you want to evaluate. For example, if you want to understand social anxiety, then you need to ensure that the questions really measure the construct of social anxiety.

5. Criterion-related validity:

To test the survey validity, compare the result with an external criterion, i.e., an established outcome. This helps you determine to what extent the survey correlates with the criterion.

The survey methodological approach to creating surveys that are reliable and valid contains a few key elements:

Turning Ideas into Public Opinion Questions

Be it any kind of survey – offline, online or a CATI Survey. It’s important to ensure that the data obtained through the survey research is an accurate reflection of the topic of interest.

To achieve this, survey questions have to be understood by all respondents consistently, in the way the researcher intended for the question to be interpreted.

Question-Wording and Sentence Structure

Another pivotal consideration when creating public opinion questionnaires is regarding question-wording and sentence structure. Questions with words that indicate extreme positions can elicit extreme responses.

Respondent’s Task

It is important to also consider the cognitive tasks the respondents will face when confronted with a survey question. To understand these tasks, researchers can use traditional and cognitive methods of pretesting to establish the reliability and validity of survey questions.

Here we have mentioned the challenges you may face in achieving reliability and validity in survey research.

1. Self-report bias:

Responses are gathered based on participant’s self report. This can lead to biases such as response bias, social desirability, and memory limitation. As a result, respondents may provide you with inaccurate responses.

2. Sampling bias:

The composition of your survey sample may not accurately represent the target population. This can lead to sampling bias and affect validity of survey research.

3. Questionnaire:

Ambiguous language or poorly designed survey can lead to response errors. You must carefully write the questions, select question types, and put them in sequence.

4. Memory effects:

Surveys need your respondents to recall past experiences. When you conduct a survey long time after an experience, it can result in memory bias. Long recall periods can lead to inaccuracies in responses.

Achieving reliability and validity in survey involves several key considerations. Here are some best practices to improve survey reliability and validity.

1. Clearly defined your objective for conducting the research and the constructs you want to measure.
2. Use clear and unambiguous language when writing your survey questions to miniize misinterpretation and response errors.
3. Provide appropriate and inclusive response options for each question to ensure the options cover every possible response for the construct.
4. Randomize the question order to reduce bias in response.
5. Leverage measurement scales that have demonstrated validity and reliability.
6. Conduct a pilot test to identify errors in your survey questions, response options, and survey flow.
7. Assess the test-retest reliability by conducting survey on same participants over time to evaluate the consistency of responses.

Achieveing reliability and validity in survey research is important to product accurate and trustworthy results. Reliability ensures consistency and validity ensures that the findings accurately represents the underlying constructs.

While achieving survey reliability and validity may be challenging, you should strive to enhance these qualities to ensure successful research. Ultimately, the two aspects contribute to the integrity of the research and enables you to make informed decisions.

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