This study addressed the usability of NCBI website, which had been the most commonly used tools by the researchers in the fields of bioinformatics and biomedicine. The main objectives of this study are threefold: (1) Investigating the user experiences of using the NCBI website tools to probe into the factors of distracting the users; (2) Proposing a new interface module based on the above investigation; (3) Evaluating the usability of NCBI website with the new interface module embedded to examine the effect of the new interface module on NCBI website through the user experiences. The investigation results showed that most of the design factors in NCBI website conform to users interface design principle except in three items: "too many subjects and concepts", "too many professional terminologies of biology", and "using English as the web language". These items would result in the problems of information discontinuity and memory over-loading. Hence, we adopted the evolutionary model to develop a so-called "Bioinformatics Terminology Identification System (BioTIS)" to cope with these problems in the interface of NCBI website. The evaluation of the new interface module showed that the participators were highly satisfactory to the changes in the NCBI interface. The analysis of questionnaires showed that the average scores of 18 questions are above 3.8, and the average scores of 72% questions are above 4 (the perfect score is 5 meaning highly satisfied). And, it is regarded that this BioTIS is beneficial to the knowledge of professional terminologies of biology and the use of NCBI website. This study concluded some valuable interface design principles for the bioinformatics resource tools for the future reference to the website builders and website re-designers. It is believed that these principles would enhance the utility rate of bioinformatics resources and would be beneficial to evaluating the user interface of interdisciplinary websites.
