The following sentences are examples for the semantic annotation provided in the FrameNet corpus for verbs in the IMPACT frame, which describes a situation in which typically "an Impactor makes sudden, forcible contact with the Impactee, or two Impactors both ... [make]  Note that the frame-specificity of semantic roles in FrameNet has important consequences for semantic role assignment, since there is no direct way to generalise across frames.
the learning for automatic assignment of semantic roles has to proceed frame-wise.