bprice

The double blinding could also be extended to the growing/harvesting, receiving, packing and shipping, and even the interpretation of analytical results. Blinding at that level, however, comes with a cost of time, material, and labor. For a project of this type and magnitude, some, if not all of those are undoubtedly not feasible. I'm assuming Karl needs to keep his day job, not to mention his family and friends! While there will be criticisms, they would be lodged regardless, simply because of the people associated with the project. To me, a main objective in the effort is not really the GM question, but the educational/participant aspect. In that regard, the limitations and flaws are actually beneficial, demonstrating the difficulties in carrying out good objective research.

I'd add that there is a certain level of trust here that participants will not manipulate results. Certainly someone who supports GM and does not expect a difference could purposely clean off both ears to ensure that result, but some faith must be put into the idea that it would be a rare occurrence with such a large number of people and, hence, of minimal impact.