What is 'Enough' Mystery Shops?

I came across this article by Dr Ujwal Kayande, a senior lecturer at the Australian Graduate School of Management which is a high level checklist of Survey Design.

Are you getting inconsistent data, do great stores all of a sudden become terrible? Then read on.

Survey design checklist
· Understand the purpose of doing a customer satisfaction survey – this is critical. Many companies collect data but don’t know what to do with it.

· Use the data you have already collected to determine what you should do in the future; this will make future data collection efficient.

· Ask questions that find differences and, therefore, give you a better signal (or reflection of the inherent variability of the retail outlets, branches or other units you are surveying).

· Watch out for indications of high unreliability in your benchmarking data. If, over a year, you find that stores drop in and out of being good at customer satisfaction when you would expect a consistent pattern, then you need to reassess the number of customers or range of stores being surveyed, or the type of questions you are asking. Another indicator of data unreliability would be a situation where the stores which do well at customer satisfaction are the ones that have poorer sales.

· Recognise that good survey design will, in most instances, result in a correlation between satisfaction and sales over time.

*Dr Ujwal Kayande is a senior lecturer in marketing at the AGSM. He received the American Marketing Association’s Donald R. Lehmann Award for best dissertation-based article in Journal of Marketing Research or Journal of Marketing (1998), and he was awarded Researcher of the Year by the Australia New Zealand Marketing Academy (ANZMAC) in 2000. He is continuing to work with Australian and US professors on improving survey design methodology.