Resumen
This paper presents an online calculator for bank charges, motivated by information asymmetry in the market for payment accounts. The calculator provides users with a personalized list of the most suitable bank accounts based on required services and monthly fee criteria. This paper outlines the conceptual foundation, workflows, and matrix of the data for the underlying logic of the calculator, as well as the design of the user interface. The proposed calculator was validated by performing an interaction cost analysis. This paper presents a novel methodology for conducting this analysis, including rules for expressing interactions in graphs for the objective evaluation of the usability of the user interface. Scenarios were defined and analyzed with the intended goal of choosing the best bank account. The interaction cost analysis then confirmed the differences in cost between traditional approaches (interacting with various web interfaces) and using a specialized online service (the calculator). The consistency of the layout and navigation contributed significantly to the final results being in favor of the proposed bank charges calculator. These conclusions are applicable not just within the selected market, but also in many others that are prone to problems arising from price information asymmetry.