3.3.4. Methodology

The first group study was held at an accessible gallery located in a social welfare center for blind and visually impaired people. The gallery has a permanent accessible exhibition, and we were able to install our test materials and perform our study in a temporal gallery next to the main gallery, and arranged them as shown in Figure 4a. The second group study was held at a school for blind and visually impaired people. The materials were installed in the main hall of the school, as shown in Figure 4b. The study was performed in the absence of other people.

**Figure 4.** Usability study setup (P = Participant; F = Facilitator; O = Observer) (**a**) Accessible gallery setup; (**b**) School for blind and visually impaired people setup.

It began with a short introduction of our team and an interview with the participant to learn about their personal information, level of vision, interests in arts, and their experience at art museums and galleries. Participants were told that they would be experiencing visual artworks through different mediums and would be asked about their experience. A 2 × 2 Latin square test design was used to counterbalance the medium (tactile graphic or IMG) and presentation order, so that the participants would experience both mediums. The artwork selection was random among the five artworks prepared, and the participants responded to a standard usability scale survey immediately after each of the first two interactions with the exhibits. After the survey and a questionnaire, they could freely explore the rest of the exhibits. To replicate the experience that they would face at an art gallery, no training on how to use the exhibits was given to the participants. Only the location of the headphones in the IMG exhibit was communicated. Participants were able to freely explore the artwork exhibit for about ten minutes, after which, they completed the survey and moved to the next exhibit.

### **4. Results and Discussion**
