While at Disney, Ferren developed a unique test for screening design & engineering talent, when he found that traditional Disney process of resume screening, reviewing bios, and interviews often did not identify the kinds of multi-domain savvy talent he needed at Walt Disney Imagineering Research & Development. Known as the Yellow Box Test, it asks the candidate to go through 100 or so items in the box, all selected for their uniqueness and interest. As featured in a 2003 article in Discover Magazine, they are scored on not just how well they can correctly identify the items, but also their thoughtfulness in explaining how they would be used and why, material selection, sourcing, cost, viable alternatives, and the technical and design principles, and even aesthetics. The candidate is also evaluated subjectively as to their enjoyment of the process, speed, enthusiasm, thoughtfulness, and appreciation of technology. For example, do they elect to first start with the things they understand, or those they do not.