The concept of interactivity and its implications for Web-based learning system design is re-examined. The author reviews the literature on the interactivity concept from the perspectives of communication, computer-assisted instruction, distance education, and interactive dimensions and functions for Web systems. A proposal is then made for a technical framework for including such dimensions and functions in Web-based learning systems. To enhance the framework's ease-of-use and overall effectiveness, each interactive function was submitted to two panels of experts for assessment and evaluation in terms of instructional necessity and programming difficulty. A discussion of the panels' feedback and the potential for future research concludes the article.