If attorneys wish to object to the admission of evidence, they must, as Rule 103(a)(1) provides, make a timely objection or move to strike, stating the specific ground of objection if that ground is not apparent from the context. Ordinarily an objection, to be timely, must be made before the witness answers. The motion to strike is required when the attorney, for any of a number of reasons, was unable to offer an objection prior to the witness' answer. The requirement in Rule 103(a)(1) that counsel must state 'the specific ground of objection, if the specific ground was not apparent from the context' is based on the principle that a rule of evidence not invoked is waived. This article also discusses the meaning of evidence being 'material' as well as a narrative offer from counsel on the occasion of an evidence-admissibility dispute.