Heejung An describes the pedagogical framework underpinning the design of an interactive Web-based HTML coding tutorial geared for novice learners attending a technical college. The author discusses the ways in which the tutorial was designed to support the learners' initial stages of cognitive skill acquisition. Of primary interest are the three components incorporated into the tutorial: worked examples, learning-by-doing, and immediate feedback on errors. The pilot version of the tutorial, referred to as the Virtual Lab, was developed and evaluated in order to further improve upon the design. The author presents the findings of a preliminary formative evaluation, which tested the overall efficacy of the tutorial as a learning tool in terms of its usability and the perceived usefulness of its specific design components. (Contains 7 exhibits and 7 figures.)