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Validity is key during the analysis and interpretation of scientific results. Without validity, results cannot be generalised and therefore any research becomes less significant. Essentially the term ‘valid’ originates from the Latin ‘vallidus’ meaning strong. But how can your findings be ‘strong’ in order to falsify your null or alternative hypothesis and still provide valid findings?

Validity: ‘Evidence that a study allows correct inferences about the question it was aimed to answer or that a test measures what it set out to measure conceptually’

(Discovering Statistics using SPSS, third edition, Field)

So for your findings to be valid they must be accurate and appropriate, whilst referring to the question you originally aimed to answer. They must represent what you tested and they must be strong in the sense that the content validity is high; clearly showing that what you have tested represents your field of study.

Validity can be expressed in different ways Internal/Criterion validity – what goes on within a study (whether the researcher tested what was meant to be tested) and External/Ecological validity – what happens outside of the study (how well the findings can be generalised to other situations and people).

To maximise validity, any potential confounding or extraneous variables need to be minimised. So to ensure your findings are valid, the research itself needs to be as tightly controlled as possible to avoid other variables other than those being measured affecting the results. If findings do not solely show the effect of one Independent variable on a Dependent variable, the research’s validity is reduced.  

‘Any research can be affected by different kinds of factors which, while extraneous to the concerns of the research, can invalidate the findings’

(Seliger & Shohamy, 1989)

To ensure validity, instruments and methods used during research must first be reliable. Without reliability, results cannot be accurate and therefore the study cannot measure what it was intended to measure, reducing the validity of the study itself. If data is not reliable, through inaccurate data collection/experimental methods, the results automatically cannot be valid.    

Data such as qualitative data can be reliable because of the depth and detail involved, but does this lend itself to validity? Qualitative data can be valid as it is true to life, but perhaps only valid for one person or a small minority? It’s very difficult to generalise Qualitative data to the larger population, but does this mean that data is still valid? Or are the findings therefore invalid as a whole?

To know whether your findings are valid, surely you must question all aspects of research as to how methods could invalidate findings. Only when these factors have been eradicated to the best of the researchers’ ability can your findings be valid.   

Comments on: "How do you know whether your findings are valid?" (5)

  1. I think you’ve made a very good point about the validity of studies, especially with stating that reliability and validity are both needed to increase each other. With variables influencing the findings so greatly, e.g. external variables such as the person’s mood on the day of the experiment, can we be sure that the findings from studies involving people are still valid? As individual differences vary so much, can any procedure compensate for this to ensure the study is still valid. This would be the same for animal studies as they too would have individual differences. So if the validity of the experiments are decreased, can we still be certain of what the results may mean?
    I think your comment at the end is a good sum up comment 🙂

    • Thanks (: I think, as variables, particularly those related to the individual participant do, and will often affect research, the researcher can do no more than prevent them from occurring as much as possible. Although no procedure could completely eradicate this, I would suggest results would still be valid, but less so. Also, I believe repeats of experiments are required to confirm what results mean in relation to your hypothesis, and whether they are as valid as they can be. Also, results from an experiment are never final as research can always be improved upon. So to some extent we can never be 100% certain of what the results mean, but they provide evidence to confirm/falsify hypotheses.

  2. I really enjoyed reading your blog 🙂 I think that it is very important for research to be valid and to have measured what was claimed to be measured, however I do also believe that it is extremely difficult to ever achieve fully valid results. There are many variables that can affect the validity of results such as the participants mood on the day of the study, and this can not be controlled by the researchers however it can influence results and may not give a true representation. There are many ways that the researchers can aim to achieve as valid results as possible and I agree with you that reliability is important too. Reliability and Validity are equally as important in order to gain the best results possible to support a theory or hypothesis. I agree that it is important to have clear and consistent methodology and that researchers conduct the study exactly the same for each participant in order to avoid invalid results.

  3. No matter how valid numerical data may be it will still be generalising to a wider population that it may not be able to truly represent. True validity may never be achievable. Significance, no matter how strong the data, will always be questionable. It is the mindset of the many over the few.
    Controlling the extraneous variables is what makes results oversimplified as although they may have little significance they still have some impact and effect on behaviour (Cronbach 1975).
    The aim of qualitative research is to gain the individual perspective and why behaviour occurs to develop theories rather than what causes what and the types of behaviour that occur and are tested in quantitative research (Rob McBride and John Schostak, 1995). Therefore they have different aims to begin with and their validity can’t be compared on the same basis. Both individual validity of qualitative research and validity to a wider population in quantitative research, have their uses and importance in developing our understanding. Human behaviour could be considered too complex, with too many variables inter-connected, to simplify to numerical comparisons or general conclusions in qualitative data so can anything be truly valid?

  4. Great post, very clear and concise
    I think it would be incredibly difficult to control every single thing within any type of experiment due to hundreds of individual differences we as humans possess, there are so many different types of threat to the all important internal validity, where the cause and effect must be protected to make sure the results are reliable. For example in developmental studies, maturation at any stage will be a threat to the validity because the child, or teenager will inevitably grow, this can lead to other changes such as changes in motivation or concentration, perhaps throwing the results off. No matter how slight this is, it is still an uncontrollable variable that researchers must take into account. We must ask if this change will still be included in the results of a study, because we can’t stop growth, and it would be impractical to void results in developmental studies because of it (or there would probably be a lot less studies in this area). We just have to trust that every other measure has been take to ensure that the results are as accurate and reliable as possible. Overall I think this relates to the second quote you used.

    I completely agree with all you have said, and like the quotes you’ve used, all finished by a well reasoned conclusion.
    Enjoyed reading this!

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