I was surprised to see Sheldrake being cited as evidence of psychic phenomena. This has been discussed in a few other threads. There seems to be a tendency to comment on small sample size and on 'seeing the data'.
In relation to his staring experiments, Sheldrake claims his sample sizes are pretty big. However, the sample size is of no interest if the conduct of the experiment is flawed.
Apparently, the conduct of the experiments is flawed in that the 'random schemes' used by Sheldrake are not random . Redoing the experiments with proper random schemes failed to identify Sheldrake's claimed effect.
Sheldrake makes other claims. Whether or not they are substantiated is difficult to see (how many people thought to examine his 'random' schemes and to investigate the effect of non-randomness?). However, given the poor conduct of the staring experiments, it is difficult to have much faith in his other experiments.
Again, if the experiment is flawed, increasing the sample size cannot help.