We looked at the following tasks for the user to do as part of the test:
CONTROL CONDITIONS AND EXPERIMENTAL VARIANTS
We planned to conduct cross-product comparison and within-product comparison:
ATTRIBUTES AND MEASUREMENTS
If we had sufficient time, we would have wanted to experiment on users with varying degrees of blindness to ensure the product was applicable for the whole blind population. Our preferred test group size would be 15-20 people with various backgrounds of age, gender, and occupation. We would use within-subjects experiment so the same users apply to multiple tasks, because we did not have access to large number of users to conduct between-subjects experiment without bias.
Given the time and resource constraints, however, we planned to test with three users. These users graciously volunteered to evaluate our functional prototype: