In developing a tool to help address academic language development, the author and his team began by identifying the challenges of presenting science text to English Language Learners and students who struggle with reading. The goal was to balance the practical and logistical challenges of identifying, teaching, and learning academic and content vocabulary with the opportunities posed by web-based visualization technologies. They involved teachers early on in this development process, and through a series of co-developer meetings with a panel of science teachers in the San Francisco Unified School District, endeavored to create a truly teacher-centric instructional tool. They also confronted the realities of the urban school setting, where resources are often a challenge and teachers vary in their experience and comfort level with classroom technology. The result was "WordSift", a web-based interface that creates a visual, interactive representation of selected text. Based on any English text entered into a "copy and paste" box, "WordSift" rapidly returns a visual display--or Tag Cloud-- that displays the top 50 words in alphabetical order, with the relative frequency of each word indicated by text size. Through regular meetings with their panel of teacher collaborators, a number of potential uses of "WordSift" were identified as useful to support instruction for teachers and reading comprehension for students. These included lesson preparation, the development of group activities for teachers, and the ability to preview text and access additional literacy support for students. "WordSift" was launched to the public on January 15, 2009. Usage statistics and teacher reviews of "WordSift" are discussed briefly in Section II. In addition to developing "WordSift" and looking at how it could be applied in the classroom, their effort also extended to the development of research to evaluate the effectiveness of "WordSift" on student reading comprehension of science text. In the spring of 2010, they implemented a systematic study with the science co-developers to see whether previewing a science text with "WordSift" would improve the reading comprehension of their students relative to when they previewed text by other means. Early results suggest that the variation observed in reading comprehension assessment scores was not significantly related to differences based on exposure to "WordSift", but rather to differences among characteristics of the students and the classes and schools in which they are enrolled. Interestingly, gender appeared to significantly mediate the treatment effect, resulting in a significant negative treatment effect for girls and a slightly positive (though not significant) treatment effect for boys. For future iterations of the web-based vocabulary tool, they may choose to pilot test it specifically with girls to get their feedback about design and features that appeal to them. (Contains 2 figures and 4 footnotes.) [For related reports, see Volume I (ED518095), Volume II (ED518089), and Volume III (ED518090).]