Difference Between BASES I & BASES II BASES I and BASES II test designs are differentiated by one simple variable: the availability of test product for evaluation by consumers. If test product is available for placement with consumers, a full BASES II design is employed and consumer evaluation of both the concept and the product are used to forecast sales. If test product is unavailable, we rely on consumer evaluation of the concept only, and use our category knowledge and access to in-market data to make necessary assumptions about the product’s likely performance (BASES I design.)