4.2.1. Pre-Procedure

Before creating the 3D models, the factor of colors was excluded so that these four concepts were not affected by colors. Moreover, blue dots in the videos indicate the location of a participant's hand when using the stereo systems. To distinguish the LCD monitor from a stereo system model, the area of the message interface is in dark blue colors.

The three-view drawings, specifications and the simulation of product mechanism for these four concepts are shown in Figures 4–7 and Table 4. The simulation of product mechanism includes the actions of taking out or placing the CD, adjusting volume, external source (MP3, iPhone) and so forth. The videos allow participants to understand how a concept operates and what the human-machine interaction looks like. Three-dimensional CAD software SolidWorks and the rendering and Three-dimensional rendering animation software KeyShot were used in this study.

**Figure 4.** Three-view drawing of Idea 1.

**Table 4.** Product specifications of Idea 1.


#### (a) Mechanical operation of the CD drive in a stereo system

**Figure 5.** Animation screenshots of mechanical simulation for Idea 1.
