sorynzar wrote:In your double blind experiment Joseph, I take it your daughter knows which group is A & B, but is unaware of which group is treated?
Yes, that's the set-up for true double-blind protocol. And I will be unaware of which plot of the garden she planted 'A' seeds in, and which she planted 'B' seeds in. The plots will be designated "east" and "west" (though they are right next to each other.)
As an update to your experiment, you should use seeds from one sunflower in order to rule out genetics, for what will probably be a mega batch of sunflowers in your treated group.
I don't have that capability, as the seeds were purchased from the Bee Project people in packets (For their research in bee population decline, they want all experimenters to use the same genetic strain of sunflowers.) Hopefully the Bee Project has standardized the genetic strain of the seeds they sell, which would be proper protocol for their purpose as well as mine. In fact, that's why it occurred to me to use these seeds for my experiments. (That, and sunflowers are VERY easy to measure the growth rates of!)
So what I've done is buy three packets, which I will mix together to randomize the selection, then divide into two groups.