We take issue with this orderly approach, arguing instead that all four cornerstones
should be foregrounded at each stage of development and validation. Instead of focusing
on the current and immediately prior cornerstone, developers should consider the
coherence of the entire instrument as they develop cornerstones that are explicitly tied to
the others. In our experience, the development and pilot testing of each cornerstone
reveal potential problems and sources of incoherence that require tweaking to most, if not
all, the cornerstones.