We first aligned with our client that test versus control analysis - our preferred shopper evaluation method - could not be used to evaluate permanent display due to its dependence on having both ‘control stores' and a ‘pre-period.’  From here, we worked to define a robust analysis approach per retailer, bespoke to the execution of display activity in both.  For Tesco, as permanent display activity had been in place in store for a number of years we were able to build a view of ‘Active display stores’ and ‘Non-Active display stores’ and adopt a 'Media versus Non-Media analysis' approach.  With Morrisons, as permanent display activity was more recently secured it was feasible to compare ‘Active display stores’ to the same stores in the year prior. Across both methodologies, our output reported at a SKU level £ Value, % Value and Unit % over time.