Reliability and validity of tests are concepts used in research to evaluate quality. Reliability indicates the consistency of the test, whether it demonstrates stable results at what is meant to measure across multiple attempts. Meanwhile, validity is the accuracy of the test, meaning does it intentionally and correctly measure what it was meant to (Cascio & Aguinis, 2019). These indicators are important to consider when selecting the test or measurement for a research design or other purposes, but it depends on context. While high reliability and validity are preferred for strong research impact, contexts may differ where it is better to select a more reliable test rather than one with high validity. Or for example, instead of using a standardized questionnaire, developing a custom-created one based on the theory researched. The best means is to choose appropriate methods for research and apply them consistently (Robertson & Cooper, 2001).
To an extent, yes, reliability and validity impact whether the results would be taken seriously. As mentioned above, there are standardized tests which have been accepted by scientific communities as highly reliable and valid, so their presence in research greatly contributes to its impact. However, even if using non standardized tests, it is vital to use the methods correctly and consistently as well since this can impact the results. For example, the test can be reliable but not valid, measuring something consistently, but a completely wrong construct (Landy & Conte, 2018). Therefore, application of tests should be evaluated, and validity likely has more impact than reliability on results. Tests can be utilized as predictors when they demonstrate high levels of reliability and validity, having both factors is important for the most accurate and predictable results. Only in those cases can they potentially be used as predictors in scientific research.
References
Cascio, W. F., & Aguinis, H. (2019). Applied psychology in talent management (8th Edition). Sage Publications.
Landy, F. J. & Conte, J. M. (2018). Work in the 21st century: An introduction to industrial and organizational psychology (6th ed.). Hoboken, NJ: John Wiley & Sons, Inc.
Robertson, I. & Cooper, C. (2001). Personnel psychology and human resources management. John Wiley & Sons Inc.