Three Main Types of Validity - Essay Example

ACTIVITY 4 EXTERNAL, INTERNAL AND CONSTRUCT VALIDITY Validity is an essential step taken while conducting the research process, where it is highly supportive in respect of substantiating the strength of the research being conducted. Validity is, Trochim submits, the best available approximation to the truth of a given proposition, inference or conclusion. (1999: 29) Validity and replication is exercised by the researchers in order to identify the strength and reliability of the research. In other words, validity aims to estimate whether or not the research has been being conducted within the parameters described in the topic, and whether or not it is observing the limitations mentioned in the research under study. Validity refers to the degree to which the instrument measures the concept the researcher wants to measure. (Zikmund, 2003) There are three main types of validity applied in the framework of social researches, which include internal validity, external validity, and construct validity. Before embarking upon the topic under study, it would be appropriate to define the three types of validity under study. Internal Validity: Internal validity refers to the relationship between the program conducted for some specific purpose and its outcome observed by the researcher. In other words, internal validity occurs in order to measure the causal relationship between the independent and dependent variables determined for the research. There exists a threat whether the other factors might change the causal effects in the relationship between the variables. External Validity: External validity refers to the researcher’s ability to generalize the findings of his research to other relevant studies or general public in order to compare the results and validate the strength of the research. External validity occurs when the causal relationship discovered can be generalized to other people, times and contexts. (Retrieved from changingminds.org) An example of external validity is the generalization of the same research conducted on our society to some other one. Construct Validity: Construct validity, Trochim (2008) states, refers to the degree to which you are measuring what you intended to measure. It concentrates upon the relationship between the operationalization of the concepts and the actual causal relationship between the variables. This is related to how well the experiment is operationalized. (Quoted in changingminds.org) Trochim has defined two types of construct validity including translation validity and criterion-related validity. Threats to Validity: All kinds of validity undergo threats in one way or the other. The researchers have elaborated these threats in a comprehensive way. There are, Creswell argues, several threats to validity that will raise questions about an experimenter’s ability to conclude that the intervention affects an outcome and not some other factor. (2008: 162) Internal validity observes three types of validity threat including single group, multiple group and social interaction threats. Single group validity threat occurs at the time when the researcher is studying on single group or community without making comparative study to two different categories of researches. Inclusion of controlled group can be helpful in respect of overcoming this threat. Similarly, in multiple validity treat, since the researcher is conducting the validity on different groups, change in time, difference of population, demographic statistics and other factors including age, sex, education and profession of the groups under study can raise threats to the internal validity of research. On the contrary, external validity threats are different from internal and construct validity threats in nature, where in external validity the researcher is unable to generalize the results of his research on every group. Consequently, there appear some problems related to comparing the research with the general public or other groups. Creswell (2008: 16) has discussed in details the threats to internal and external validity. Because of the narrow characteristics of the participants in the experiment, Creswell observes, the researcher cannot generalize to individuals who do not have the characteristics of participants. (2008: 185) He has referred to history, maturation, regression, selection, mortality and diffusion of treatment as internal threats, and interaction of selection, setting, history and their treatment as the external threats to validity. Internal validity threat related to history is related to the changes occurred in the group under study with the passing of time and the units of analysis i.e. population experiences transformation in views, performance, nature, quantity and quality as well. Maturation internal validity threat stresses upon the change in the thinking and quality of the group under study, where the researcher witnesses improvement or maturation in the ideas and behavior of the participants. Regression is, according to Creswell, another threat to internal validity, due to the very fact that in regression, the participants obtaining highest scores are selected, which do not represent the entire units of analysis and may put the entire research procedure of validity into grave jeopardy. Similarly, mortality also affects the validity on the basis of the exclusion of some of the participants from the research process, which consequently is unable to present the complete representation of the research already conducted. Creswell also declares diffusion of treatment as a threat to internal validity. Under the circumstances where participants get the opportunity of sharing their views under the same atmosphere, the research cannot be declared as the valid one, which cannot maintain difference between the controlled and experimental participants. (Creswell, 2008: 17) The main difference between internal, external and construct validity is this that the internal validity focuses upon the change in the duration and time of the research, while external validity threats look for the problems in the generalization of the research on different situations, circumstances, groups and participants, and alteration in the minds, views and nature of participants make the generalization really hard nut to crack. On the contrary, the first and the foremost threat faced in the construct validity is inadequate preoperational explication of constructs, where it any change in quality and quantity affects the relationship between the variables. These changes can both be related to external and internal threats. Hence, there exists similarity between these three validity threats that all the three are affected by transformation and alteration. But it does not mean that all the three threats are similar in nature. On the contrary, internal threats lays stress upon alteration in time and location, while external validity threat discusses transformation of quality and quantity of the participants. In the same way, construct validity threat is more interested in founding out the change in the cause and effect between the variables due to any factor created after the research has already been conducted on the relevant topic or upon the similar population. Mono operation bias is also one of the construct validity threats. Mono-operation bias pertains to the independent variable, cause, program or treatment in your study -- it does not pertain to measures or outcomes. (socialresearchmethods.net) Both internal and external threats measure the strength of change occurred due to some specific factor, while construct validity threat measures the threats created by the cause applied on the dependent variable in the research process. REFERENCES: Cozby, P. C. (2009) Methods in behavioral research (10th Ed.). Boston: McGraw Hill Higher Education. ISBN: 9780073370224 Creswell, J. W. (2009) Research design: Qualitative, Quantitative, and Mixed Methods Approaches (3rd Ed.). Thousand Oaks, CA: Sage Publications. ISBN: 9781412965576 Trochim, W., & Donnelly, J. (2008) The research methods knowledge base (3rd Ed.). Mason, OH: Cengage. ISBN: 9781592602919 Zikmund, W. (2003) Business research methods (7th Ed.). Thousand Oaks, CA: Thomson/South-Western. ISBN: 9780030350849 Types of Validity. (Retrieved from http://changingminds.org/explanations/research/design/types_validity.htm) Threats to Construct Validity. (Quoted in http://www.socialresearchmethods.net/kb/consthre.php) Read More