Research Methods and Validity - Essay Example

? Research Methods- Validity Research methods- Validity Introduction Validity is a very significant componentof any scientific research. Initially, validity was regarded as a logical positivist concept and therefore restricted to quantitative research but further developments in scientific studies began to incorporate the concept of validity in qualitative research. The word validity is derived from the Latin word, Validus which means to be strong (Kendler, 2006). Validity in research therefore has to do with how strong the research is, in terms of its design, measurements and the conclusion. Validity can be defined as the degree to which a scientific study measures what it was really ion tended to measure. It refers to the degree to which a scientific concept, measurement or conclusion has been founded to the real concepts and how it accurately corresponds to the real world (Brains, & Manheim, 2011). Basically, validity is used to measure the soundness of scientific research and to test if the study really answers what it was intended to. The concept of validity applies in both research designs and research methods. In quantitative research, validity is determined based on various empirical concepts such as objectivity of the research, universality, truth, deductive reasoning, tangible evidence and mathematical truths among others. A valid quantitative research is one that is very strong and that which is consistent with universal laws and whose methods and conclusions can be verified objectively (Cozby, 2001). These considerations ensure that scientific research methods are very strong and increase the degree to which the finding from valid research can be trusted and relied upon. Validity is also used in qualitative research to maintain objectivity and universal application of scientific concepts. Validity is therefore important in analyzing the usefulness, appropriateness and meaningfulness of scientific research studies. Validity in data collection helps to ensure that the phenomenon chosen for scientific study really represent the intended population of study and that they can be relied upon to make appropriate objective conclusions (Brains, Willnat, Manheim, Rich 2011). Body Scientific studies can be affected by various different factors, which may be either internal or external to the research but have tremendous influence on the findings of the research to the extent that they can invalidate the study. It is necessary to control all the factors that can negatively impact on the scientific study in order to boost the validity and reliability of the study. The concept of validity is important in research because it helps the researcher to determine what types of tests and methods are cost effective, ethical and are appropriate for use in a particular study. An invalid research cannot be used to make any scientific generalizations and cannot be taken seriously for scientific purposes (Kendler, 2006). Validity should not however be confused with reliability in research. Whereas validity has to do with how strong a scientific study is in relation to the real world, reliability has to do with the consistency of research findings if the study is to be replicated under similar conditions by other independent researchers. A study can be proven to be reliable without necessarily being valid and vice versa. Despite being different, the two concepts are key components of any scientific research and both should be met in order for a study to achieve its intended objectives. There are four main types of validity in scientific research namely internal, external, statistical conclusion, and construct validity. Each of these types of validity has a different approach to validity. They are also used to measure different aspects of scientific study and can be used to assess various aspects of the study to ensure all threats to validity are brought under control (Brains & Manheim, 2011). Each of the types of validity faces its own threats that may inhibit the validity of the study if not properly controlled. Each of the types of validity as well as the threats associated with them are as described below; External Validity External validity deals with the extent to which general inferences can be derived from findings of a particular research to define relationships between the variables being investigated in a research and other variables in other settings. External validity is said to have been established when conclusions of a particular study can be generalized to other variables in other contexts (Cozby, 2001). External validity therefore enables us to generalize conclusions of scientific studies. External validity can also be used to ensure consistency of scientific research in the sense that if the same study were to be conducted using similar parameters to yield the same results. An example of external validity would be trying to derive inferences from a scientific study about heart diseases in men Europe and generalizing them to apply to women and men in other parts of the world. External validity can be divided in to two distinct subtypes of ecological validity and population validity. Like any other type of validity, external validity is susceptible to lots of threats that need to be brought under control in order to ensure success of scientific studies. A major threat to external validity if the sample selected for the study can be relied upon to represent the general population and yield valid results and conclusions. Other threats include interaction effects resulting from bias as well as the experimental variable, reactive effect of testing, reactive effects of experiments and the multiple treatment interference in cases where the effects of treatments done earlier become hard to erase. These threats can be controlled by following the correct procedures in sampling avoiding bias and prejudice from pretest results. Internal Validity Internal validity deals with causal relationship between two variables in a scientific study. It is the deductive estimate of the extent to which we can draw conclusion about cause-effect relationship among variables based on the setting of the research, the types of measurements used, and the research design. Internal validity is usually affected by mistakes made in the research itself for instance failing to control some of the major variables in the research design. Internal validity is meant to ensure that scientific studies follow the principle of causal relationships between variable in that causes and effects can be easily established. Internal validity is usually affected by threats such as the size of the population, attrition, history, subject variability and the size of the subject population among others. These threats can however be brought under control by paying close attention to data collection methods in order to avoid instrument problems and controlling major variables in the study to avoid problems arising from the research design. Construct validity Construct validity can be defined as the extent to which inferences can be made about higher and older constructs under investigation based on the specific characteristics of the research (Cozby, 2001). It refers to the degree to which the major constructs of a study do actually measure what the theory of the research postulates. For instance in an intelligence study, construct validity would be concerned with the extent to which questionnaires used to collect data about IQ actually measure intelligence. Construct validity is closely related to internal validity since it relates to the design of the study to determine if all measure have been taken to ensure everything is covered. Content Validity Content validity can be described as the systematical examination of the contents of a scientific research to determine whether the study covers a representative sample that can be used to measure the behavior of the general population (Cozby, 2001). This is a non- statistical form of validity but requires a lot of attention to ensure that the content used in the study is within the required realm of science. It is linked to internal validity as it affects how the research is conducted from an internal perspective. For instance, s study gathering information about intelligence can determine its content validity by determining if the questionnaires used cover all the areas needed to get useful information about intelligence. Content validity ensures that the research covers all areas that it is expected to cover in a particular topic so as to generate useful exhaustive knowledge that can be applied to the wider population (Kendler, 2006). Criterion Validity Criterion validity can be described as the process of comparing the findings of a specific scientific study with those of other similar studies that have already been proved to be valid (Cozby, 2001). It usually involves a correlation between tests conducted in a particular research and already established criterion from other studies that are regarded as being validly conducted. For instance in a study examining how to select employees to work for a company in a job selection process, this study can be compared with other valid criteria from studies about employee performance. Criterion validity is an external type of validity since it seeks to relate a particular study to other studies done on the same topic. Face Validity Face validity can be described as the estimation of whether a particular test in a scientific research appears to measure certain known criterion, although it does not guarantee that the study actually measures the estimated criterion (Cozby, 2001). When a test does not seem to be measuring what is expected, it is said to have low face validity. In cases where tests can be affected by faking or malingering, low face validity can actually make the research to be valid since some respondents can be encouraged to provide honest answers. Face validity is closely related to content validity only that face validity employs statistical methods while content validity is non-statistical (Kendler, 2006). Since it affects the content of research, face validity is an internal type of validity. An example of face validity is a study trying to investigate intelligence, questionnaires can be said to have a low validity if the questions do not directly gather information about academic performance that reflects individuals IQ. Statistical conclusion validity This validity refers to the extent to which we can make inferences about two variables and how they are related in order to strengthen the relationship. The relationship inferred could either be positive or negative depending on how the research was conducted. Conclusion Validity is a very important element of any scientific study as it affects the final conclusions and theories developed from the studies. Validity determines the seriousness with which scientific studies are to be conducted and how knowledge derived from such studies ought to be regarded (Cozby, 2001). If a study is invalid, its results and findings cannot be taken as serious as they ought to be and will therefore have no scientific value. It is therefore important to ensure all measures are taken to ensure validity of scientific studies is maintained. This will involve examining all available threats to validity and bringing them under control. References American Educational Research Association, Psychological Association, & National Council on Brains, W & Manheim, R. (2011). Empirical Political Analysis 8th edition. Boston, MA: California: Mayfield Publishing Company. cervical flexion-rotation test in C1/2-related cervicogenic headache". Manual therapy 12 (3): 256–62. Cozby, P. C (2009). Methods in behavioral research. 10th ed. Boston: McGraw-Hill Higher Cozby, P.C. (2001). Measurement Concepts. Methods in Behavioral Research (7th ed.). diagnoses". The American Journal of Psychiatry 160 (1): 4–12. Education. Kendell, R & Jablensky, A (2003). "Distinguishing between the validity and utility of psychiatric Kendler, K. S (2006). "Reflections on the relationship between psychiatric genetics and Kramer, Geoffrey P., Douglas A. Bernstein, and Vicky Phares (2009), Introduction to clinical psychology. 7th ed. Upper Saddle River, NJ: Pearson Prentice Hall. Measurement in Education. (1999). Standards for Educational and Psychological Testing. Washington, DC: American Educational Research Association. Ogince, M; Hall, T; Robinson, K; Blackmore, AM (2007). "The diagnostic validity of the psychiatric nosology". The American Journal of Psychiatry 163 (7): 1138–46. Read More