Validity is one of the most important aspects of a research study ( ). Validity establishes how accurate and credible ( ) the findings are and how thorough one's research is and did the study measure what it intended to measure ( ). There are four main types of validity in research: conclusion validity, internal validity, external validity, and construct validity. This paper will compare and contrast the characteristics of external, internal, and construct validity. It will also identify the threats associated with external and construct validity and the impact of such treats in research.
Internal Validity
Internal validity is when a researcher is able to determine a relationship based on the program and results
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If the sample is not randomized, the threats to the study become much higher. Critics will be able to make statements that the participants not being randomilzed are not a good representation of all people and this study only reflects those people that have the same demographics as those who participated in the study.Trochim and Donnelly (2008) indicate, when a sample has been randomalized, it is important that the participants participate in the study and to keep the dropout rates low. This will increase the validity of the study. Randomizing helps prevent critics from identifying the reason why participants did not participate or why participants dropped from the study. Having a high dropout rate may cause critics to determine that the results were scewed based on why participantsss dropped and who actually completed the …show more content…
If a pre-test occurs in the study the pre-test its self will effect the results and will not be able to be generalized to another population that did not receive the pre-test. Critics could say that the pre-test provided clues to the participants which effected the results, whereas if a pre-test was not given this would not be the case. The results are not going to be generalized to participants who do not receive a pre-test.
The effects of how participants react knowing they are a part of a study may change how participants react, thus causing and external threat to the study results. Another reactive effect may be if the participants receive more than one treatment in the same study. Receiving more than one intervention is taking away the validity that this study can be generalized to a single treatment study.
Providing a random sample and plenty of data to indicate how results can be generalized to different populations, settings, and time will help improve the external validity of a study. Trochim and Donnelly (2008) indicate that doing the research in a variety of places with different people and at different time will also increase the external validity of a study. As in internal validity the research design and methodology used to gather the data will help improve validity of the study.
Construct
Considering that the researcher protects himself or herself and the participants, a lot of unwanted circumstances including new infections on both sides are prevented thus limiting the miscellaneous costs in the research budget. It also assures the participants that they are protected and thus will come to no harm during the study. This ensures that they are willing to cooperate and thus help the scientific community and humanity as a whole by providing the relevant data for a given investigation. Safety here also prevents errors by ensuring that the possible errors are caught on time. This then translates into results that are not only very reliable but also largely replicable onto another sample population, making them relevant in drawing a generalized
...g the criteria noted above in the checklists proved in Houser (2015). It has been noted with evaluation that it appears to have the components of adequate criteria for being a credible source and having credible authors. The design of being a qualitative study has been evaluated and contains most of the components of the noted checklist. There are ethical issues that are well documented and weighed. The problem statement and purpose statement have been noted and the literature review was evaluated thoroughly. The sampling strategy is purposeful and explained in depth. The study was compared and is noted that its methods are of trustworthy quality. To optimize EBP is the ultimate goal in conducting a study of this nature. It has been shown that there is a significant amount of knowledge obtained from the study and there is a probable use for this information.
Another weakness is that although it is a longitudinal study: as it takes place over a large period of time, participants will likely drop out. This therefore may lead to sample bias as there may be only a certain type of person in the sample and therefore is no longer representative. Because of this, the research done by Hodges and Tizard cannot be generalised to the public and is weakened, along with low population validity due to only British children being studied.
... objective in nature, thus producing accurate data. Nevertheless, Allington and McGill-Frazon established that “reduction of a complex phenomenon to a few quantifiable variables can lead to over simplification of the phenomenon” (p.445). In other words, for observations to be complete, a combination of qualitative and quantitative data is necessitated in order to explain the totality of the phenomenon. An advantage of pre-test and post-tests designs is that it can be conducted with a single group or a control group. In the projected research topic, a pre-test and post-test was used with a group to maximize the internal validity. Neverthess, in the projected research topic, the experimental design is used to illustrate a cause and effect between two variables. The disadvantage is that external elements pose a threat to accuracy (Leedy & Ormrod, 2010, p.230).
In order to have a successful, reliable experiment you need sufficient data and evidence, reliable research, variables to test and a follow – up experiment. There are several types of variables you need to do an experiment. An independent variable is the manipulated experimental factor that is changed to see what the effects are. A dependent variable is the outcome. This factor can change in an experiment in reaction to the changes in the independent variable. An experimental group is the group of participants that are exposed to the change that the independent variable represents. The control group is participants who are treated in the same way as the experimental group except for the manipulated factor which is the independent variable (King 24). Proper data, evidence and research is also needed so the experiment turns out correctly and you know what you are testing. A follow – up experiment is not required, however it helps the validity of the conclusion of the experiment. Validity is “the soundness of the conclusions that a researcher draws from an experiment” (King 25). Conducting a follow – up experiment will help researchers and people alike see if the experiment worked properly, continues to help people and see how participants are doing after the experiment is over.
The sampling procedures that can be utilized in evaluation research is vast. The selected sampling procedure is important in the consideration of external validity. External validity generalizes the findings to individuals in the study sample with characteristics that are alike (DiClemente et al., 2013). Although, not all research studies will require a sampling procedure that would deliver an external validity.
There are advantages to using RCT, firstly, there the effect of using randomization will “wash out” any population bias and it is easier to blind than observational studies (O'Brien, 2013). The results can be analyzed with reliable statistical tools and the participants can be clearly identified (O'Brien, 2013). The disadvantage of this method is that it is often expensive and time cons...
I found it very interesting when talking about experimental research how important validity is. There were two types internal validity and external validity. Internal was more about manipulation/controlling and removing any influence of extraneous variables. By doing so the goal is to be assured that any observed differences between groups in the study is attributed only be differences in the independent variable (e.g., treatment, intervention, and instruction) and no other factors. So, my understanding of this concept is basically understanding and verifying that the research was done right. I was wondering if anyone else got the same conclusion and if there are any other important parts to my understanding of internal validity that I am
However, both characteristics of reliability and validity are important and can be used in many studies, such as the self-rating and other- ratings of daily behavior. Reliability refers to the internal consistency, inter-rater reliability, test-retest, and standardized scoring. In other words reliability means that study scores have to be constant with repeatability of the findings. Validity also refers to convergent validity, discriminant validity, and predictive validity. Validity refers to the reliability or credibility of the research. If the findings in a study, reliability and validity are valid they must be reliable.
...the data did not involve member checking thus reducing its robustness and enable to exclude researcher’s bias. Although a constant comparative method was evident in the discussion which improved the plausibility of the final findings. Themes identified were well corroborated but not declared was anytime a point of theoretical saturation Thus, the published report was found to be particularly strong in the area of believability and dependability; less strong in the area of transferability; and is weak in the area of credibility and confirmability, although, editorial limitations can be a barrier in providing a detailed account (Craig & Smyth, 2007; Ryan, Coughlan, & Cronin, 2007).
Internal validity, unlike external and construct validity, deals with causal relationships. In other words, the question is whether any additional research that is found is actually associated with the study that is being conducted. The question, again, is whether we can be confident that the outcome of the study is a result of the experiment itself. What this means is that internal validity is the extent to which a change in a given variable is caused by the change in another variable.
Now within the rest of this paper you will be finding a few different things getting discussed. Staring it off we will be discussing the articles that we have found to make our arguments and hypotheses. After wrapping up the literature reviews we will be discussing the hypotheses thus continuing onto our variables and indicators. Once we discuss our hypotheses we will be moving onto the research design. The research design will have our general issues, sampling, and methods.
A researcher uses an experiment to scientifically test out a hypothesis. In an experiment there are many different factors that are involved. There is the independent variable, which is the cause, it is the one that is being manipulated, and the dependent variable, which is the effect, is the response. When conducting a experiment it is important to make sure that the only thing than can affect the dependent variable is the independent variable. This is known as internal validity. Using random assignment to separate the participants into groups helps eliminate any outside factors, and creates an equal chance for all participants to be apart of the experimental conditions. There are many pros and cons to this type of method. The experimental method creates a strong control of the variables involved in the experiment, which allows an easier determination on cause and effect. If needed, it is fairly easy to replicate an experiment and is less time consuming than other research methods. However there are many downfalls as well. When conducting an experiment the setting of where the experiment is taking place is more artificial which may cause certain behaviors that wouldn’t occur in real life. This is known as external validity, which is the measure of how much the results of a study can be generalized and used in different situations, and people. To improve external validity cover stories are created when conducting experiments so the participants are not aware of what is really going on, or experiments are done in a natural setting as opposed to in a laboratory. However, this creates less control over confounding variables that can affect the experiment, which can create bias results (Aronson,
Researchers work hard to eliminate bias from outcomes through approaches that diminish subjectivity and modification from unknown sources. Randomization, use of well-matched controls, and blinding of analysts and researchers are some ways to try to a...
An important part of an experiment is random assignment. If the participants for the study are randomly assigned to create two groups, and the researcher has enough participants in the study to have the desired “probabilistic equivalence” (Trochim & Donnelly, 2008, p. 187) then the researcher will feel a sense of confidence that the study will have internal validity in order to assess whether or not the treatment caused the outcome hypothesized. Well-c...