The purpose of this study aims at assessing students' knowledge categories by visual technology for the particulate nature of the matter (PNM) with three-tier diagnostic instrument. This research sets up both visual and nonvisual designs for two group students to evaluate different knowledge categories including 185 college students' percentage of correct answering rates, a lack percentage of knowledge understanding, and cognitive percentage of overconfident domains. All results are expounded in the following three major aspects: 1. Students with visual technology make more accomplishments than those with nonvisual technology; 2. Students with nonvisual technology demonstrate less knowledge understanding than those with visual technology; 3. After practices of visual technology, students perform higher percentage of self-assessment up to a surprising level in their knowledge cognitive domain. To sum up, an integrated visual technology with three-tier diagnostic instrument can facilitate students' involvement and assessment for comprehensive understanding in PNM.