[en] In thin film analyses obtained using sputtering techniques, primary ion implantation and ion beam mixing effects frequently produce significant alteration on the substrate before it can be sampled by the sputtering front. The present state of qualitative and quantitative understanding of these effects is discussed, with particular reference to: ion yield matrix effects and interface transients in secondary ion mass spectrometry, reduction of overlayer sputter rates due to ion beam mixing, the role of ion beam mixing in preferential sputtering, and the use of ion beam mixing to allow quantitative analysis of interfacial layers. (orig.)