- Reliability vs validity: what’s the difference?
- Instrument, Validity, Reliability
- Reliability and Validity of Measurement
Reliability vs validity: what’s the difference?
Validity and reliability in Qualitative research (6 strategies to increase validity)and
There are several types of validity that contribute to the overall validity of a study. The two main dimensions are Internal and External validity, and further sub-types can be added under these headings. Internal Validity is concerned with the degree of certainty that observed effects in an experiment are actually the result of the experimental treatment or condition the cause , rather than intervening, extraneous or confounding variables. Internal validity is enhanced by increasing the control of these other variables. External Validity Is concerned with the degree to which research findings can be applied to the real world, beyond the controlled setting of the research.
The validity of the research findings are influenced by a range of different factors including choice of sample, researcher bias and design of the research tools. The table below compares the factors influencing validity within qualitative and quantitative research contexts Cohen, et al. A wide range of different forms of validity have been identified, which is beyond the scope of this Guide to explore in depth see Cohen, et. The chosen methodology needs to be appropriate for the research questions being investigated and this will then impact on your choice of research methods. The design of the instruments used for data collection is critical in ensuring a high level of validity.
In general practice, qualitative research contributes as significantly as quantitative research, in particular regarding psycho-social aspects of patient-care, health services provision, policy setting, and health administrations. In contrast to quantitative research, qualitative research as a whole has been constantly critiqued, if not disparaged, by the lack of consensus for assessing its quality and robustness. This article illustrates with five published studies how qualitative research can impact and reshape the discipline of primary care, spiraling out from clinic-based health screening to community-based disease monitoring, evaluation of out-of-hours triage services to provincial psychiatric care pathways model and finally, national legislation of core measures for children's healthcare insurance. Fundamental concepts of validity, reliability, and generalizability as applicable to qualitative research are then addressed with an update on the current views and controversies. The essence of qualitative research is to make sense of and recognize patterns among words in order to build up a meaningful picture without compromising its richness and dimensionality.
These related research issues ask us to consider whether we are studying what we think we are studying and whether the measures we use are consistent. Reliability is the extent to which an experiment, test, or any measuring procedure yields the same result on repeated trials. Without the agreement of independent observers able to replicate research procedures, or the ability to use research tools and procedures that yield consistent measurements, researchers would be unable to satisfactorily draw conclusions, formulate theories, or make claims about the generalizability of their research. In addition to its important role in research, reliability is critical for many parts of our lives, including manufacturing, medicine, and sports. Reliability is such an important concept that it has been defined in terms of its application to a wide range of activities. For researchers, four key types of reliability are:. Equivalency reliability is the extent to which two items measure identical concepts at an identical level of difficulty.
Again, measurement involves assigning scores to individuals so that they represent some characteristic of the individuals. But how do researchers know that the scores actually represent the characteristic, especially when it is a construct like intelligence, self-esteem, depression, or working memory capacity? The answer is that they conduct research using the measure to confirm that the scores make sense based on their understanding of the construct being measured. This is an extremely important point. If their research does not demonstrate that a measure works, they stop using it.
Instrument is the general term that researchers use for a measurement device survey, test, questionnaire, etc. To help distinguish between instrument and instrumentation, consider that the instrument is the device and instrumentation is the course of action the process of developing, testing, and using the device. Instruments fall into two broad categories, researcher-completed and subject-completed, distinguished by those instruments that researchers administer versus those that are completed by participants. Researchers chose which type of instrument, or instruments, to use based on the research question. Examples are listed below:. Example usability problems include:.
Instrument, Validity, Reliability
Date published July 3, by Fiona Middleton. -
Reliability and Validity of Measurement