Market share estimation: µ = mean difference between 2 auditing methods


This diagram illustrates that the p-value puts a numerical value to the scale of the type of diagram used in the previous page — it describes whether the data are consistent with the null hypothesis, H0.

The p-value is an index of credibility for the null hypothesis, µ = 0.

Also mention that the interpretation of the p-value is identical for all hypothesis tests, regardless of the details of H0 and HA.

The traditional retail store audit is a widely used marketing research tool among consumer packaged goods companies. The retail stort audit involves periodic audits of a sample of retail audits to monitor inventory and purchases of a particular product. Another auditing procedure, weekend selldown audits, has been proposed as a less expensive alternative.

The market shares of 10 brands of fruit juice were estimated using both of the store audit methods. Do the two methods result in the same estimates, on average? The data are paired, so we analyse the difference in estimates for each product (traditional minus weekend selldown) and test whether the underlying population mean of these values is zero.