Presentation on validity and reliability in research methods
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This document discusses validity and reliability in research methods. Validity refers to how well a study measures what it intends to measure. There are two types of validity: internal validity, which is correctness for the studied group, and external validity, which is generalizability. Reliability means results are consistent and repeatable. The document also discusses how reliability and validity are viewed differently in qualitative versus quantitative research, noting qualitative research aims to understand phenomena in context rather than manipulate variables. Strategies like triangulation can increase validity and trustworthiness in qualitative studies.
Presentation on validity and reliability in research methods
- 1. Validity and Reliability in Research Methods Presented by: Dr Mehwish Iqbal (Institute of health management) DUHS, Karachi
- 2. Introduction: • The principles of validity and reliability are fundamental cornerstones of the scientific method. • Reliability is a necessary ingredient for determining the overall validity of a scientific experiment and enhancing the strength of the results.
- 3. What is Validity? • Validity is an expression of the degree to which a test is capable of measuring what it is intended to measure. Golafashani (2003) • A study is valid if its results correspond to the truth; there should be no systematic error and the random error should be as small as possible. • There are two types of validity: internal and external.
- 4. Types of Validity:- • Internal validity: • Internal validity is the degree to which the results of an observation are correct for the particular group of people being studied. For example, measurements of blood hemoglobin must distinguish accurately in participants with anemia as defined in the study. • Analysis of the blood in a different laboratory may produce different results because of systematic error, but the evaluation of associations with anemia, as measured by one laboratory, may still be internally valid. • Internal validity can be threatened by all sources of systematic error but can be improved by good design and attention to detail.
- 5. External validity: • External validity requires external quality control of the measurements and judgments about the degree to which the results of a study can be extrapolated. This does not require that the study sample be representative of a reference population. • For example, evidence that the effect of lowering blood cholesterol in men is also relevant to women requires a judgment about the external validity of studies in men. • External validity or generalizability is the extent to which the results of a study apply to people not in it (or, for example, to laboratories not involved in it).
- 6. What is Reliability? • The idea behind reliability is that any significant results must be more than a one-off finding and be inherently repeatable • Other researchers must be able to perform exactly the same experiment, under the same conditions and generate the same results. This will reinforce the findings and ensure that the wider scientific community will accept the hypothesis.
- 7. What is Reliability? • Joppe (2000) defines reliability as: …The extent to which results are consistent over time and an accurate representation of the total population under study is referred to as reliability and if the results of a study can be reproduced under a similar methodology, then the research instrument is considered to be reliable.
- 8. Kirk and Miller (1986) identify three types of reliability referred to in quantitative research, which relates to: • The degree of consistency of results • The stability over time • The similarity within a given time period. Salkind (1997) defines reliability as something that is reliable will perform in the future as it has in the past. A reliable test or measure of behavior can measure the same thing more than once and will result in the same outcome. Reliability is based on the scores, performance of any one on any variable generate a score composed of three components shown below:
- 9. Reliability and validity in qualitative research • However, the concepts of reliability and validity are viewed differently by qualitative researchers who strongly consider these concepts defined in quantitative terms as insufficient. • In other words, these terms as defined in quantitative terms may not apply to the qualitative research paradigm (Golafashani, 2003) • Golafashani (2003) described qualitative research uses a naturalistic approach that seeks to understand phenomena in context-specific settings, such as real world setting in which the researcher does not attempt to manipulate the phenomenon of interest and only try to unveil the ultimate truth.
- 10. Reliability and validity in qualitative research • The idea of testing reliability in qualitative paradigm is viewed as a way of information elicitation. Therefore most important test of any qualitative study is its quality. A good qualitative study can help us to “understand a situation that would otherwise be enigmatic or confusing” (Eisner, 1991) • According to Stenbacka, (2001) “the concept of reliability is even misleading in qualitative research, if a qualitative study is discussed with reliability as a criterion; the consequence is rather that the study is no good”.
- 11. • To ensure reliability in qualitative research, examination of trustworthiness is crucial. Seale (1999), while establishing good quality studies through reliability and validity in qualitative research, states that the “trustworthiness of a research report lies at the heart of issues conventionally discussed as validity and reliability” • Three approaches to validity in qualitative research are validation as investigation, as communication, and as action (Kvale, 1989). • Qualitative researchers are of the view that the term validity is not applicable to qualitative research, but at the same time, they have realized the need for some kind of qualifying check or measure for their research. • Therefore, the quality of a research is related to generalizability of the result and thereby to the testing and increasing the validity or trustworthiness of the research.
- 12. List of Strategies to Increase Validity in Qualitative Research Paradigm
- 13. Conclusion:- It is also through this association that the way to achieve validity and reliability of a research get affected from the qualitative researchers’ perspectives which are to eliminate bias and increase the researcher’s truthfulness of a proposition about some social phenomenon (Denzin, 1978) using triangulation. Then triangulation is defined to be “a validity procedure where researchers search for convergence among multiple and different sources of information to form themes or categories in a study” (Creswell & Miller, 2000, p. 126). Therefore, reliability, validity and triangulation, if they are to be relevant research concepts, particularly from a qualitative point of view, have to be redefined as we have seen in order to reflect the multiple ways of establishing truth.