The sketching software developed in this thesis, is aimed to serve as an intelligent design tool for the conceptual design stage of the mechanical design process. This sketching software, Sketch Pad for Windows, closely mimics the traditional paper-and-pencil sketching environment by allowing the user to sketch freely on the computer screen using a mouse. The recognition algorithm built into the application replaces the sketch stroke with the exact CAD entity. Currently, the recognition of two-dimensional design primitives such as lines, circles and arcs has been addressed. Since manufacturing requires that the design concepts be detailed, sketches need to be refined as detailed drawings. This process of carrying design data from the conceptual design stage into the detail designing stage is achieved with the help of a convertor that converts the sketch data into DesignView (a variational CAD software). Currently, only geometrical information is transferred from the sketching software into DesignView. The transparent graphical user interface built into this sketching system challenges the hierarchial and regimental user interface built into current CAD software. / Graduation date: 1995