Teachers’ impact on dental students’ exam scores in teaching pathology of the oral cavity using WSI

Background There is an overall increasing tendency at medical universities around the world to digitize microscope histopathological slides from teaching collections for web-based studies [1]. For the last seven academic years (2005 2012), we have developed and evaluated a user-friendly on-line interactive teaching and examination system to facilitate student access to Pathology of the Oral Cavity course material, including histological laboratory specimens. It made microscope laboratory studies in oral cavity pathology more efficient and teaching resources have become available for interactive use from anywhere at any time, independent of class schedules. The WebMicroscope allows students to independently explore entire histological slides. Students control the content and the rhythm of delivery of the content. Digital slides produced using whole slide imaging (WSI) can be visualized at any magnification and moved in the x-y axis, which perfectly imitates using a traditional microscope and a glass slide [2]. Examination which applies WSI technology on-line requires a sophisticated test management software. In the past, we used an examination system that was restricted to using standard static images. This was technically less challenging and followed a routine which was similar to that of conventional paper-based examinations [3,4]. WSI is more demanding as it requires the use of innovative image serving and viewing software and, because of the enormous size of the images, a storage facility capable of storing hundreds of gigabytes. However, it reflects much better the usual laboratory activities [5]. Using WSI allows asking questions about the overall diagnosis without specifically highlighting the key diagnostic features as it must be done in the field of view of a static image. Even if a question refers to a specific field of view, the student can zoom out and see that field in the overall context of the slide. This contextual information easily available in virtual microscopy is essential in teaching students both how to find the key diagnostic fields within a whole slide and to perceive how a diagnostic field fits into the surrounding non-diagnostic slide context. Our first seven-year experience in developing and using an examination system which applies WSI indicates that configuring an on-line practical exam in Pathology of the Oral Cavity requires flexibility over the question types that can be asked. Our practical examination in oral pathology is scheduled at the end of the 3rd year dental curriculum of students in the Department of Clinical Pathology at the University of Medical Sciences in Poznan, Poland. Because the number of new students enrolling every academic year is high, students work in groups which are supervised by different teaching assistants with heterogeneous teaching experience. The aim of this study was identifying if in such a context the teacher has still an impact on the students’ exam scores.