In this work the relation between electron pair emissions and electron correlation was studied. The experiments were motivated by theoretical calculations. Here the electron pairs were excited by the absorption of an electron. The key aspect is the comparison of a high correlated materials, as the 3d transition metal oxide NiO, and weak correlated materials, as the metal Ag. Impressively, the NiO signal compared to Ag is enhanced by a factor of 10. It was shown, that this is an intrinsic effect. It is not a result of the angular acceptance of the instrument, nor the mean free path of the electrons. To show these, the layer-by-layer method was applied for NiO films on a Ag(100) crystal. Further materials (Ni, Co, Fe, Pd, Cu, and CoO ) were studied and a relation between single and coincidence count rate was found. Furthermore, the electron pair diffraction on Ag(100) was studied.