We have developed a Free Body Diagram (FBD) Assistant that provides students with an opportunity to practice FBD construction and to receive feedback. The system includes a mechanism for tracking students' progress over time. A previous version was written using Macromedia Flash 5 and data storage and retrieval was via a SQL server. This was a stand-alone package that integrated several functions including an interactive FBD drawing tool, an assessment and feedback package, a FBD authoring

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... and session administration. Although this software package was effective in training students in the proper construction of a FBD, the feedback provided to students was rather superficial (e.g., "2 vectors are missing"). Instead of further complicating the tool by adding code that provides more meaningful feedback to students, we felt this could be done more effectively within the Courseware Authoring and Packaging Environment (CAPE) developed by the Vanderbilt, Northwestern, Texas and Harvard/MIT Engineering Research Center (VaNTH). The FBD Assistant was redesigned by extracting the drawing tool and the authoring tool, and converting them into stand-alone interactive modules. CAPE was used to provide feedback to students and the VaNTH Experimental Learning Management System (eLMS) replaced the administration area. An XML-RPC compatible I/O specification was designed that allowed communication between the FBD drawing tool and the eLMS. The resulting system is considerably more versatile than the original version. When a student submits a solution, the eLMS records administrative information and passes the solution on to diagnostic modules authored in CAPE for a detailed analysis. A message providing meaningful feedback to students is displayed by the FBD drawing tool. Comparison of Free Body Diagrams constructed before and after use of the tool indicates that student performance is improved following interaction with the FBD Assistant. Students can use this asynchronous system to gain practice in constructing free body diagrams at their own pace and students' records can be analyzed to indicate progress over time.