Introduction
Validity is regarded as one of the most successful approximation to the effectiveness of an idea, research, or suggestion. In other words, validity makes the evaluation of the chosen project thorough and definite. There are two types of validity, external and internal; and each of them has its own peculiarities, nature, and variables.
In this paper, the two types of validity will be evaluated from the perspective of the implemented by a teacher scenario during which one group of students has to undergo changes and follow new curriculum, and another group continue studying under the same conditions.
Considering the conditions provided, there are several threats to both external and internal validity which may influence the results of the research and have to be evaluated, and the threats to internal validity like maturation, instrumentation, or selection are harder to prevent because they are true causes of the results achieved, when external validity touches upon generalization of the situation.
Scenario chosen
A teacher implements a new curriculum on the exam score where students are divided into two groups. In one class, students undergo considerable changes and improvements with the help of a new curriculum, and in another class, students continue to use the previous evaluation system.
The results of the experiment are the following: the vast majority of students from the experimental group get more than 90, and the control group’s results are from 85 to 90.
Threats of validity in study: nature and peculiarities
According to Berg and Latin, internal validity is “the extent to which the research condition is controlled so that the independent variable causes an effect or change in the dependent variable” (p. 202); and external validity is a kind of extent in accordance with which the results of research may be generalizable (Lodico, Spaulding, & Voegtle, 2010).
Threats to validity in the study under consideration are the following: the maturation that deals with a number of biological and psychological aspects, the idea of novelty helps to attract students’ attention and involve them into the process of education, social desirability that lies into the fact that students rely on their own interests and evaluators, and finally, the threat of instrumentation that is based on various measurement tools inherent for different groups.
These are the threats of both internal and external validity; this is why the scenario offered by the teacher has to be evaluated from both perspectives to find out the most effective decision. The threats to internal validity like maturation or instrumentation “represent specific reasons why a researcher’s conclusions about a casual relationship between variables may be completely wrong” (Ary, Jacobs, Razavieh, & Sorensen, 2009, p.283).
And the factors of novelty and social desirability are considered to be the threats to external validity which are not as important as the internal ones but still remain to be noticeable issues in the research.
Possible reduction of the threats
There are several ways of how it is possible to reduce the influence of threats of the chosen study. For example, the threat of novelty is possible to overcome if a teacher chooses a gradual implementation of the curriculum. Students need to understand the essence of a novelty as well as define the priorities of the chosen idea.
Social desirability as a threat to external validity may be decreased due to thorough attention to students’ interests and demands. A teacher should implement a new idea in case he/she is confident students are ready and eager to undergo improvements. Threats to internal validity such as maturation or instrumentation may be also reduced by a number of steps.
Maturation “involves events of change, where the change would occur anyway, that happen during the duration of the program” (Hodges & Videto, 2005, p. 164); attention to students’ development has to be paid.
The teacher should be ready to compare groups and evaluate their skills, so that this teacher is able to control the threat of maturation. Instrumentation is another significant threat that comes from variety of tools offered: differential data and the use of different equipment may lead to another considerable threat of a study. To reduce a threat, the teacher should use the same material and tools for all groups.
Peculiarities of validity: which one is hardest to prevent
Considering peculiarities of threats to internal and external validity in the chosen study, internal validity and its threats seem to be more crucial and harder to prevent. The study will be valid in case the outcomes are attributed to the experimental treatment but not to all those extraneous variables.
In case a person cannot grasp new material and get used to the tools offered by a teacher because of personal inabilities, it will be a teacher who should take responsibility for appropriate evaluation of the material and the most effective tools. Threats to internal validity are more significant in this study due to the necessity to focus on internal requirements and teacher’s direct impact.
Research that promotes the program’s effectiveness
In general, to achieve the most successful results in the study under consideration, it is better to pay more attention to the factors which influence the development of the curriculum.
As an example, it is possible to implement a new idea during some period of time to make students adapt to it, then find some time to evaluate students’ attitudes and demands, and finally, to explain how exactly students may benefit from the chosen curriculum. Only in case students are aware enough of the program, the results may be satisfied.
Reference List
Ary, D., Jacobs, L.C., Razavieh, A., & Sorensen, C. (2009). Introduction to Research in Education. Wadsworth: Cengage Learning.
Berg, K.E. & Latin, R.W. (2007). Essentials of Research Methods in Health, Physical Education, Exercise Science, and Recreation. Baltimore, MD: Lippinctott Williams & Wilkins.
Hodges, B.C. & Videto, D.M. (2005). Assessment and Planning in Health Programs. Mississauga, ON: Jones & Bartlett Learning.
Lodico, M., Spaulding, D. T., & Voegtle, K. H. (2010). Methods in Educational Research: From Theory to Practice. San Francisco, CA: John Wiley & Sons.