Reliability and validity in Quantitative marketing research

Quantitative marketing research is the request of quantitative research techniques to the field of marketing. It has roots in both the positivist view of the world, and the modern marketing viewpoint that marketing is an interactive process in which both the buyer and seller reach a satisfying agreement on the "four Ps" of marketing: Product, Price, Place and Promotion. As a social research method, it usually involves the creation of questionnaires and scales. People who react are asked to complete the survey. Marketers use the information so obtained to understand the needs of individuals in the marketplace, and to make the strategies and marketing plans. Reliability and validity in Quantitative marketing research: Research must be tested for reliability, generalizability, and validity. Generalizability is the capacity to make inferences from a sample to the population. Consistency is the extent to which a calculate will produce consistent results. Test-retest reliability checks how similar the results are if the research is repeated under similar circumstances. Stability over repeated measures is assessed with the Pearson coefficient. Alternative forms reliability checks how similar the results are if the research is repeated using different forms. Internal consistency reliability checks how well the individual measures included in the research are converted into a composite measure. Internal consistency may be assessed by correlating performance on two halves of a test. The value of the Pearson product-moment correlation coefficient is adjusted with the Spearman-Brown prediction formula to correspond to the correlation between two full-length tests. A commonly used measure is Cronbach's α, which is equivalent to the mean of all possible split-half coefficients. Reliability may be enhanced by increasing the sample size. Validity asks whether the research measured what it intended to. Content validation checks how well the content of the research are related to the variables to be studied. Are the research questions representatives of the variables being researched. It is an expression that the items of a test are drawn from the domain being measured. Criterion validation checks how meaningful the research criteria are relative to other possible criteria. When the criterion is collected later the goal is to establish predictive validity. Construct validation checks what underlying construct is being measured. There are three variants of construct validity. They are convergent validity, discriminate validity, and nomological validity.