What Is Content Validity?

Content validity is a fundamental consideration in psychometrics, ensuring that a test measures what it purports to measure.

Content validity is not merely about a test appearing valid on the surface, which is face validity. Instead, it goes deeper, requiring a systematic and rigorous evaluation of the test content by subject matter experts.

Content validity:

• Evaluates whether test items comprehensively represent the domain being measured.
• Usually determined by expert judgment.
• Ensures no important components of the construct are missing.
• Checks that items are relevant and appropriate for the intended purpose.

Content validity is a fundamental consideration in psychometrics, ensuring that a test measures what it purports to measure.

For instance, if a company uses a personality test to screen job applicants, the test must have strong content validity, meaning the test items effectively measure the personality traits relevant to job performance.

Why is content validity important in research?

Content validity is crucial in research because it ensures that a measurement tool accurately reflects and covers the full scope of the construct being investigated.

• Statistical inference: Content validity serves as the bedrock for drawing inferences from research results. If the content of a test does not adequately represent the construct being measured, then the statistical significance based on those test scores might be inaccurate or misleading.
• Justification of test use: Ensuring content validity is essential for justifying the use of a test for a specific purpose. This is particularly relevant in applied settings, such as educational testing, clinical assessments, or personnel selection.

Assessing Content Validity

Content validity is not a one-time assessment but rather a continuous effort to refine and improve measurement instruments.

• Expert review: This is the most common method, where subject matter experts evaluate the test items for relevance and representativeness. Engage a diverse group of experts in the content review process to minimize the influence of individual biases. They may use rating scales, matching exercises, or provide qualitative feedback on the items.
• Item-domain congruence: This involves calculating a statistical index that quantifies the degree of agreement among experts regarding the relevance of each item to the specified domain.
• Factor analysis: This statistical technique can be used to analyze the structure of response consistencies and uncover underlying dimensions or facets within the test items, helping to evaluate the representativeness of the content.
• Alignment methodology: Primarily used in educational testing, this approach assesses the alignment between statewide educational tests and curricula. It involves rating the benchmarks (educational objectives) within a curriculum framework and then rating the test items for their congruence with those benchmarks.
• Content validity ratio: Content Validity Ratio (CVR) is a quantitative method for assessing content validity, particularly in situations where the construct being measured is closely tied to observable behaviors in specific settings. CVR helps determine whether a panel of subject matter experts considers a specific test item essential for measuring the intended construct.

Examples

Education Assessment

Content validity is considered particularly important in educational achievement testing.

This is because such tests aim to measure how well students have mastered specific knowledge and skills taught in a particular curriculum or course.

Ensuring that the test items are relevant to and representative of the instructional content is paramount to making valid inferences about student learning and achievement.

For example, when creating a final exam for a history class, the instructor needs to make sure the exam questions cover the key concepts, events, and historical figures that were taught throughout the course.

There are a number of factors that specifically affect the validity of assessments given to students, such as (Obilor, 2018):

• Unclear Direction: If directions do not clearly indicate to the respondent how to respond to the tool’s items, the validity of the tool is reduced.
• Vocabulary: If the vocabulary of the respondent is poor, and he does not understand the items, the validity of the instrument is affected.
• Poorly Constructed Test Items: If items are constructed in such a way that they have different meanings for different respondents, validity is affected.
• Difficulty Level of Items: In an achievement test, too easy or too difficult test items would not discriminate among students, thereby lowering the validity of the test.
• Influence of Extraneous Factors: Extraneous factors like the style of expression, legibility, mechanics of grammar (spelling, punctuation), handwriting, and length of the tool, amongst others, influence the validity of a tool.
• Inappropriate Time Limit: In a speed test, if enough time limit is given, the result will be invalidated as a measure of speed. In a power test, an inappropriate time limit will lower the validity of the test.

Interviews

Each interview question should be directly relevant to the construct being explored.

The set of interview questions should be representative of the full scope and complexity of the construct. This means including questions that address all the key dimensions or facets of the construct.

Avoid questions that are tangential or unrelated to the central theme.

Pilot testing the interview questions with a small sample of participants before conducting the main interviews is a valuable step.

This allows you to identify any issues with question-wording, sequencing, or clarity.

It also helps you assess whether the questions are eliciting the desired information and providing a rich understanding of the topic.

Interview data are often influenced by contextual factors, such as the relationship between the interviewer and the interviewee, the interview setting, and the participant’s own motivations and experiences.

These factors can affect the validity of the data and make it difficult to generalize findings.

Questionnaires

Questionnaires rely on the respondents’ ability to accurately recall information and report it honestly. Additionally, the way in which questions are worded can influence responses.

To increase content validity when designing a questionnaire, careful consideration must be given to the types of questions that will be asked.

Open-ended questions are typically less biased than closed-ended questions, but they can be more difficult to analyze.

It is also important to avoid leading or loaded questions that might influence respondents’ answers in a particular direction. The wording of questions should be clear and concise to avoid confusion (Koller et al., 2017).

Psychological Test Development

Construct validity focuses on whether a test truly measures the theoretical construct it’s designed to measure.

It’s about demonstrating that the test scores reflect the underlying psychological attribute of interest, like intelligence, anxiety, or personality traits.

It’s more than just checking if a test predicts an outcome; it’s about understanding the meaning of the test scores in relation to the psychological theory behind the construct.

Researchers need to ensure that the test items accurately reflect the full scope and complexity of the construct being measured (e.g., anxiety, depression, personality traits).

This involves defining the construct clearly, outlining the domain of observables, and selecting items that cover the relevant aspects of the construct.

Content Validity vs Construct Validity

Content validity focuses on the items within the test, while construct validity focuses on the underlying latent construct or factor.

• Content validity concerns the adequacy with which the test samples the domain of interest. It refers to the degree to which a psychological instrument’s items accurately reflect the concept being measured.
• Construct validity is a broader concept that encompasses content validity as one aspect. It considers the extent to which a test or assessment truly measures the underlying psychological construct it claims to measure.

Content validity focuses on the relevance and representativeness of the items to the construct’s content domain. It assesses whether the instrument’s content is appropriate for its intended use.

This type of validity is often evaluated deductively, by carefully defining the construct and then systematically selecting items from that domain.

Construct validity goes beyond content, investigating the meaning of the test scores and how they relate to the theoretical framework of the construct.

This may involve examining the test’s internal structure, such as its factor structure, to see if it aligns with the theorized dimensions of the construct.

It also involves examining the relationships between the test scores and other variables, including measures of related constructs and criteria, as well as responses to experimental interventions.

For example, if a test is designed to measure intelligence, construct validity would involve examining whether the test scores are related to other measures of intelligence, such as academic achievement or problem-solving ability.

To illustrate the distinction:

• Imagine a spelling test created by randomly selecting words from a children’s spelling workbook. This test would likely have high content validity because the items are directly sampled from the domain of interest.
• However, content validity alone does not guarantee that the test measures the broader construct of spelling ability. To assess construct validity, we might examine whether scores on this spelling test correlate with performance on other tasks that require spelling skills, such as writing essays or taking dictation.

Here’s a table summarizing the key differences between content validity and construct validity:

Feature	Content Validity	Construct Validity
Definition	The extent to which a psychological instrument’s items accurately and fully reflect the specific concept being measured.	The extent to which a test truly measures the underlying psychological construct it claims to measure.
Scope	Narrower; focuses specifically on the items and their relationship to the content domain.	Broader; encompasses content validity and other forms of validity evidence.
Focus	Relevance and representativeness of items to the content domain.	Meaning of test scores in relation to the theoretical framework of the construct.
Evaluation	Primarily assessed seductively: * Defining the construct clearly. * Systematically selecting items from that domain. * Expert judges review items to assess relevance and representativeness.	More complex and multifaceted, using a variety of methods: * Examining the test’s internal structure (factor analysis). * Investigating relationships with other variables (convergent and discriminant validity). * Studying responses to experimental interventions.
Example	A spelling test with words randomly sampled from a spelling workbook has high content validity because the items are directly from the domain of interest (the workbook).	To establish construct validity for the spelling test, one might investigate if the test scores correlate with essay writing performance, which requires spelling skills. This helps determine if the test truly measures the broader construct of spelling ability.

Key Points:

• Construct validity subsumes other types of validity, including content validity. Think of content validity as a necessary but insufficient condition for construct validity. A test can have good content validity but still lack construct validity if it doesn’t truly measure the intended psychological construct.
• Construct validity is an ongoing process. It requires the accumulation of evidence from multiple sources to support the meaning and appropriate uses of test scores. This may involve refining the test, revising the construct theory, or gathering additional data.
• Both content and construct validity are essential considerations in the development and evaluation of psychological instruments. By ensuring both types of validity, researchers and practitioners can create tests that are both accurate and meaningful.

References

American Psychological Association. (n.D.). Content Validity. American Psychological Association Dictionary.

Haynes, S. N., Richard, D., & Kubany, E. S. (1995). Content validity in psychological assessment: A functional approach to concepts and methods. Psychological assessment, 7(3), 238.

Koller, I., Levenson, M. R., & Glück, J. (2017). What do you think you are measuring? A mixed-methods procedure for assessing the content validity of test items and theory-based scaling. Frontiers in psychology, 8, 126.

Lawshe, C. H. (1975). A quantitative approach to content validity. Personnel psychology, 28(4), 563-575.

Lynn, M. R. (1986). Determination and quantification of content validity. Nursing research.

Chicago

Obilor, E. I. (2018). Fundamentals of research methods and Statistics in Education and Social Sciences. Port Harcourt: SABCOS Printers & Publishers.

OBILOR, E. I. P., & MIWARI, G. U. P. (2022). Content Validity in Educational Assessment.

Newman, Isadore, Janine Lim, and Fernanda Pineda. “Content validity using a mixed methods approach: Its application and development through the use of a table of specifications methodology.” Journal of Mixed Methods Research 7.3 (2013): 243-260.

Rossiter, J. R. (2008). Content validity of measures of abstract constructs in management and organizational research. British Journal of Management, 19(4), 380-388.