Wikiversity/Cold fusion/Contrary evidence
This seminar will study experimental reports of results that appear to contradict the cold fusion or LENR hypothesis.
Such papers are in two classes: those which represent simple replication failure, but which do not present or discover and demonstrate through controlled experiment, the nature of the artifact(s) behind other positive reports, and those who do uncover such artifact. Particular attention may be paid here to reports which demonstrate artifact, either directly through experiment, or through improved analysis of primary experimental data, sufficient that the original report impeaches itself as to its conclusions.
Complicating all this is that reputed replication failures have commonly not been accurate replications, so experimental conditions varied. In addition, it appears that cold fusion, if real, is sensitive to possible subtle details of material structure, and, in particular, the palladium lattice is not necessarily stable and static; as it is loaded with deuterium, it expands, and contracts with deloading, and cracks form. The surface of the material, considered by most reearchers to be the active zone, also develops other complex chemistry and structure. Thus, even if the same material is used, it may vary from day to day.
In more recent work, the reliability of excess heat has been increased, but it remains common that no heat is seen. Experiments that look for products or other measurements correlated with heat do not suffer from this problem, because the experiments with no anomalous heat become controls, otherwise identical as to a normal understanding of conditions.
In the early days of cold fusion, searches for neutrons were considered, if negative, to demonstrate that the findings were not the result of "fusion." However, it has become an accepted characteristic of the Fleischmann Pons Heat Effect that not only are no neutrons generated, but there is no charged particle radiation, either, above 20 KeV (see Hagelstein, 2010?). The negative neutron results (and results that purport to show very low levels of neutrons) confirm this widespread understanding.
As well, there were searches for helium in the bulk material. It was not found. That was also considered conclusive by some. But most researchers now consider cold fusion to be a surface effect, with helium being found only in the outgas or within a few microns of the surface (and at least one search for helium removed the outer 25 microns to avoid measuring atmospheric contaminatino.) So, again, negative results for helium in the bulk palladium can be seen as confirmation of what became known, later.
Earthtech has done a series of reports, often more carefully done and presented than work that it might be impeaching. It's the opinion of Abd that Scott Little and Earthtech is fulfilling a very important critical function in the cold fusion community.
See  (2006?).