心流經驗(flow experience)可以用愉悅感覺、專注、沈浸與高度涉入來描述；心流理論指出，當所面對的挑戰與自身所具備的技術能力達到大致平衡的狀態時，個體內在就會激發出心流經驗。我們在本文中從研究的效度觀點來檢視心流理論本身曖昧不清與其限制之處，也分別在操作化、理論詮釋、衡量與指標上，加以討論研究者在進行心流研究時，尤其在網路環境中所必須面對與克服的挑戰。本文從效度觀點回顧的努力，希望能夠擴充心流理論的應用，加強理論的緊密度，並能增加我們對於線上心流經驗的瞭解。

Flow experiences are represented by enjoyable feelings, concentration, immersion, and intensive involvement. Situations which challenges and skills are perceived to be roughly equivalent are thought to facilitate the emergence of flow. From the perspective of research validity, we reviewed the ambiguities and constraints of flow theory in its operationalization, interpretation, measurement, and indicator. Further we pointed out the challenges of research validity when studying the online flow experiences. The success of this article should extend the scope of flow theory applications, enhancing the coherence of flow theory, and increasing understanding of exploring online experience.