Validity- the state or quality of sees the focus group as a sample from a target population — and thus presumably regards generalization as a vmq norming population: is it representative of the population you want to use it for how about gender and cultural representation. Reliability, validity and representative sample in research john and webb (2002, p148) distinguishes between validity and reliability, arguing that the first one is the extent to which a research is capable of measuring what it is supposed to be measuring and the second one is the extent to which a research delivers consistent results. Get help on 【 reliability, validity and representative sample in research essay 】 on graduateway huge assortment of free essays & assignments the best writers. 1 validity and reliability 2 types of validity 3 external validity 31 population validity 32 content validity is the estimate of how much a measure represents every single element of a construct face validity is a measure of how representative a research project is 'at face value,' and whether it.
Validity is the extent to which a concept, conclusion or measurement is well-founded and likely corresponds accurately to the real world based on probability the word valid is derived from the latin validus, meaning strong. Validity concerns are far more serious problems in measurement than reliability concerns, because an invalid measure is probably measuring a different construct than what we intended, and hence validity problems cast serious doubts on findings derived from statistical analysis. External validity is the extent to which the results of a study can be generalized from a sample to a population establishing eternal validity for an instrument, then, follows directly from sampling. Vmq norming population: is it representative of the population you want to use it for be sure to view this in terms of the sample size and the makeup of the populations used to norm the instruments this adds important meaning to the reliability and validity coefficients.
Simply, the validity of the measuring instrument represents the degree to which the scale measures what it is expected to measure it is not same validity is all about the genuineness of the research, whereas reliability is nothing but the repeatability of the outcomes this article will break down the. Evidence about the reliability, validity and latent structures of the dass and dass-21 among adolescents in low and low-middle the results are robust with a systematically recruited, large sample, participants representing students from three main types of high schools and institutions in. Validity is concerned with the accuracy of our measurement, and it is often discussed in the context of sample representativeness reliability, on the other hand, is concerned with the consistency of our measurement, that's the degree to which the questions used in a survey elicit the same type of. Reliability vs validity reliability and validity seem to be synonymous, but they do not mean the same thing they are actually different things, different terms when they are explained in a. Internal validity is concerned with the degree of certainty that observed effects in an experiment are actually the result of the experimental reliability is an essential pre-requisite for validity it is possible to have a reliable measure that is not valid, however a valid measure must also be reliable.
Test reliability and validity are two technical properties of a test that indicate the quality and usefulness of the test reliable assessment tools produce dependable, repeatable, and consistent information about people in order to meaningfully interpret test scores and make useful employment. It should also apply to people beyond the sample in the study different methods vary with regard to these two aspects of validity experiments, because they tend to be structured and controlled, are often high on internal validity. Validity and reliability posted on jan 26, 2017 in other subjects determine if the test covers a representative sample of the area of conduct to be measured criteria, empirical alludes to the practical use of technology in the field of application, indicating the effectiveness of the test to predict. As pointed out by hughes (1981), it is quite difficult to sample representative language skills as a result of inadequate needs analyses and the lack of reliability is in fact a prerequisite to validity in performance assessment in the sense that the test must provide consistent, replicable information.
These two standards are reliability and validity reliability refers to the consistency of test scores how consistent a particular student's test scores are content or curricular validity is generally used to assess whether a classroom test is measuring what it is supposed to measure for example, a test is. The concern with reliability and validity is not limited to predictors but applies to criteria as well when the validator assumes that his predictor is representative of a given class of situations, he is content validity if it adequately represented (sampled), in terms of its items, the content of the course. When we look at reliability and validity in this way, we see that, rather than being distinct, they actually form a continuum on one end is the situation where the concepts and methods of measurement are the same (reliability) and on the other is the situation where concepts and methods of measurement are different ( very discriminant validity. Reliability and validity are often discussed separately but sometimes you will see them both referred to as aspects of generalizability the normative sample should (for hopefully obvious reasons) be representative of the target population - however this is not always the case, thus norms and the.
Reliability and validity slide 1 in this lecture, i discuss measurement, validity, and our sampling procedures and response rates were as good as you can get this suggests that if they content or face validity is merely an assessment of whether or not scale items are adequately representative of. Types of validity validity content validity face validity criterion related concurrent predictive construct validity 13 content validity uses logical reasoning and hence easy to apply extent to which a measuring instrument covers a representative sample of the domain of the aspects measured whether items and questions cover the full range of. The short form-8 (sf-8) is a widely used instrument for measuring health-related quality of life (hrqol) the purpose of the current study is to evaluate the reliability and validity of the chinese version sf-8 using a large, representative sample of city residents in mainland china. Representation - does the sample include all the variables within the population such as age, gender, social class, religion, education level which might affect response even with a large sample if the sample is not representative then bias in the data will occur cultural bias - has the data been.