As there are no words I can use that will be useful to this forum, I shall not pursue it either until such time as I have done more experiments.
FYI I have never claimed that dowsers are any better at avoiding the ideomotor effect than the rest of the population. I do however think it is not the sole effect in dowsing.
As for an earlier reference by a contributor to teaching dowsing in a class room - that is like trying to teach Formula 1 racing in an inflatable dinghy.
I chose plywood after testing at my home - around 90 miles from the test area. But as I dug the trench, filled it before covering with plywood, I admit that the selection could have been compromised by the ideomotor effect. An earlier plan had been that one walkway would be covered with carpet, another would be raked level and a third would be covered with ply. Preliminary tests (not viewed by me) showed that the carpet and raking did not disguise the worked area well enough - hence plywood all over.
Re Pixel 42's question 3 - the area of Bucks that the test was conducted in has been subject to very little rain for three years (you must have seen how low the water was in the pond). "Little" does not mean none. Just before the trenches were dug there was a downpour. There has been no rain since. The soil is drying out.
Ward asked about others who had dowsed near the road. Some years ago I had looked for the water source of the pond. I found a response near the back of the pond but continued walking and found another near the road, I continued and found another three running at right angles to the road. It considered that the four were more likely to be 19th century or older land drains. On Sunday I showed the location of two of these to the assembled viewers – two people found positive responses (a third, Prof Mike Heap thought he might have too but was not sure). My two sons, their partners and my two granddaughters had each found them on earlier occasions. Your photo of Prof. Chris French was taken at that position and shows how not to hold dowsing rods – they were pointing slightly downwards and so were already in a stable low-gravity position. I had demonstrated earlier that they should be pointed slightly upwards to a point of instability so that any very slight rotation of the arm/wrist (2 minutes on a watch face) would tip the rods to fall under the action of gravity, thus rotating outwards or inwards across the body.
As for Pixel 42’s carp about it not being a field test – it certainly wasn’t a truck, pipe or tube test. It was the first field test that I know of. She was in a field. I assume her “Good grief” meant that she could think of no logical argument to mine. If she knows the rate of attenuation of the dowsing signal through plywood, perhaps she could send me a reference. I don’t. I admit that I had inadvertently designed an experiment where the results could be interpreted in two ways. Bad but not blinkered. Putting sand or water into bottles and hiding them under upturned buckets I consider to be a worse experiment as only a supernatural helper could produce a positive result (could you tell the difference between coffee and petrol under such conditions).
“Old men as dowsers.” I strongly advise younger men with a career in science ahead of them to steer well clear. It is too stressful and even its investigation in as unbiased way as possible will do your scientific standing no good at all. At my age I can ignore it.
What has amazed me in this forum is the attitude that I should stop experimenting. It is my time, my money, my reputation such as it is. It is only my work that can convince me that there is nothing else to investigate. It certainly isn’t the words of a group which believes there is nothing that cannot be explained by the wooo of the ideomotor effect.
I shall not contribute to this forum again until I have more experimental results to impart. Enjoy your talking.
