The validity of a research study refers to how well the results among the study participants represent true findings among similar individuals outside the study. This concept of validity applies to all types of clinical studies, including those about prevalence, associations, interventions, and diagnosis.

Here are seven important factors affect external validity: Population characteristics (subjects) Interaction of subject selection and research. Descriptive explicitness of the independent variable. The effect of the research environment.

There are eight threats to internal validity: history, maturation, instrumentation, testing, selection bias, regression to the mean, social interaction and attrition.

Generalizability refers to the extent to which the results of a study apply to individuals and circumstances beyond those studied. (1) Com- monly referred to as external validity, generalizability is the degree to which a given study’s findings can be extrapolated to another population.

In addition to concerns about generalizability, qualitative methodology is rebuked because studies are often difficult to replicate. Future researchers may not have access to the same subjects, and if other subjects are used, results may differ.

Reliability in qualitative research refers to the stability of responses to multiple coders of data sets. It can be enhanced by detailed field notes by using recording devices and by transcribing the digital files.

2–4 In the broadest context these terms are applicable, with validity referring to the integrity and application of the methods undertaken and the precision in which the findings accurately reflect the data, while reliability describes consistency within the employed analytical procedures.

Validity in research is concerned with the accuracy and truthfulness of scientific findings. Some qualitative researchers have argued that the term validity is not applicable to qualitative research and have related it to terms such as quality, rigor, and trustworthiness.

There are four aspects of trustworthiness that qualitative researchers must establish: credibility, dependability, transferability, and confirmability. We begin the series here with a discussion of credibility. Credibility is the first aspect, or criterion, that must be established.

Qualitative Validity

1. Credibility. The credibility criteria involves establishing that the results of qualitative research are credible or believable from the perspective of the participant in the research.
2. Transferability.
3. Dependability.
4. Confirmability.

Ensuring validity Ensure that your method and measurement technique are high quality and targeted to measure exactly what you want to know. They should be thoroughly researched and based on existing knowledge.

Validity and reliability are key aspects of all research. This is particularly vital in qualitative work, where the researcher’s subjectivity can so readily cloud the interpretation of the data, and where research findings are often questioned or viewed with scepticism by the scientific community.

Validity is important because it determines what survey questions to use, and helps ensure that researchers are using questions that truly measure the issues of importance. The validity of a survey is considered to be the degree to which it measures what it claims to measure.

Bias can affect both the internal validity and the external validity of a study. A study that has major methodologic issues, however, lacks internal validity, and we probably should not accept the results.

There are several ways to counter threats to external validity:

1. Replications counter almost all threats by enhancing generalizability to other settings, populations and conditions.
2. Field experiments counter testing and situation effects by using natural contexts.

Some researchers believe that a good way to increase external validity is by conducting field experiments. In a field experiment, people’s behavior is studied outside the laboratory, in its natural setting.