This is another nice little demonstration I use to show my less scientifically minded friends that are not the type to come on a forum like this when explaining how valid something like 6% is within Ganzfeld and that they can do for themselves.
Open up Excel and do a quick formula using the randbetween function. (Before the skeptics start Yes I know Excel is not the perfect RND # generator algorithm and is not exactly based on chance but it is not the point)
Copy into cell A1 the function =RANDBETWEEN(1,4) and copy it to cells A1 to A10. This returns a random number between 1 and 4.
In cell B1 type in the amount of trials 10 to start with. This will be used by the formula.
In cell C1 enter the following formula =SUMIF(A1:A2000,1) This will tell you how many 1's you in your trial. Chance would be 1 in 4.
In cell D2 enter in the following formula. =SUM(C1/B1)*100 This will give you the %. 25% is what we would expect is chance.
Now when you run 10 trials in Excel several times I get 30%, 50%, 60% and even 70%. Really means nothing because not enough sample size.
Now copy the formula from A1 to A50 and change B1 to 100.(# of trials). I am getting 27%, 17%, 26%, 24%, 22%. The %'s are starting to hover more around the 22-27% range with the odd anomoly like 17%.
Now copy the formula from A1 to A500 and change B1 to 500.(# of trials). What do we now notice. The %'s are 27.4, 24.7, 26.2, 22.4, 26.8 Starting to get a little interesting... we are between 22.4% - 26.8% even though it is only 500 trials. The chances of getting to 6% variability either side of chance has reduced significantly. In fact I re-ran this about 20 times and it didn't once get close to 31% or 19%.
So what happens when we run 2000 trials. What we see now is that when run the %'s of heads coming up are 25.15, 25.95, 24.9, 24.55, 24.75. We are now getting %'s in the 24.55 to 25.95% so up to 0.95% above chance. You never see anything even remotely approaching 6% above chance.
To get 6% when running that many trials are astronomical odds.
So the problem isn't the % it's the probability of achieving 6% above chance in most of the Ganzfeld studies which as Dean Radin correctly points out is significant. We have something here which needs further investigation.