美國活動產(chǎn)業(yè)協(xié)會（Events Industry Council，原Convention Industry Council）在專業(yè)詞表中定義event為：An organized occasion such as a meeting, convention, exhibition, special event, gala dinner, etc. An event is often composed of several different yet related FUNCTIONS. EIC所說的Event是指有組織的活動，如會議，大會，展覽，特殊活動，節(jié)日宴會等。

Charles Bladen等認為，活動就是臨時性有目的的集會。（Events are temporary and purposive gatherings of people. ）活動具有四個特征：（1）臨時性（They are temporary in nature）；（2）集體性（They are gatherings of people）;（3）儀式性（They are often displays of ritual）；（4）唯一性（They are, in some sense, unique occurrences）.