Purpose: In tertiary institution, some students find it hard to learn database design theory, in particular, database normalization. The purpose of this paper is to develop a visualization tool to give students an interactive hands-on experience in database normalization process. Design/methodology/approach: The model-view-controller architecture is used to alleviate the black box syndrome associated with the study of algorithm behavior for database normalization process. The authors propose a visualization "exploratory" tool that assists the learners in understanding the actual behavior of the database normalization algorithms of choice and also in evaluating the validity/quality of the algorithm. This paper describes the visualization tool and its effectiveness in teaching and learning normalization forms and their functional dependencies. Findings: The effectiveness of the tool has been evaluated in surveys. It shows that students generally viewed the tool more positively than the textbook technique. This difference is significant to p less than 0.05 (t=1.645). The mean interactions precision and calculated value using expert judge relevance ratings show a significant difference between visualization tool and textbook performance 3.74 against 2.61 for precision with calculated t=6.69. Originality/value: The visualization tool helped students validate/check their learning of normalization process. Consequently, the paper shows that the tool has a positive impact on students' perception. (Contains 2 tables and 12 figures.)