Null result

Generally, a null result is a result which is null (nothing): that is, the proposed result is absent. In science, it is an experimental outcome which does not show an otherwise expected effect. This does not imply a result of zero or nothing, simply a result that does not support the hypothesis. The term is a translation of the scientific Latin nullus resultarum, roughly meaning "none as a consequence".

Statistics
In statistics, specifically, a null result occurs when there are non-significant differences between experimental and control conditions. While some differences may in fact be observed, they are below the threshold set prior to testing for rejection of the null hypothesis. The significance threshold varies, but is often set at 0.05 (5%).