Test phase evaluation has been common practice in industry for decades, but it is not often used in designing interpretation.
However, evaluating written information, for example, is easy, quick and very effective. The written word is still a central medium for most sites. Therefore an optimal text design plays a major role.
Other interpretive media your visitor comes in contact with can also be evaluated, whether in detail or as a whole. The methods of collecting data can range from simple questionnaires, group interviews, media response analysis or interviews of multipliers to pilot studies with mock-ups.