Some tasks are easy, like choosing a flavor of ice cream; other tasks are hard, like choosing a medical treatment. Consider, for example, an ice cream shop where the varieties differ only in flavor, not calories or other nutritional content. Selecting which ice cream to eat is merely a matter of choosing the one that tastes best. If the flavors are all familiar, such as vanilla, chocolate, and strawberry, most people will be able to predict with considerable accuracy the relation between their choice and their ultimate consumption experience. Call this relation between choice and welfare a mapping. Even if there are some exotic flavors, the ice cream store can solve the mapping problem by offering a free taste.
— Richard H. Thaler, Cass R. Sunstein, Nudge
Thaler and Sunstein are describing part of what I understand as a mental model. New users aren’t blank slates. They approach interactions with a system using preconceptions shaped by prior experiences with analogous systems.
For example, imagine you encounter chocolate as a possible ice cream choice for the first time. (I know, it’s inconceivable. Everyone loves chocolate ice cream. Right? I know I do. Please bear with me.) If you’ve had chocolate candy and any other kind of ice cream before, you may have a rough idea of what to expect. Chocolate has a particular flavor, and ice cream is sweet, cold, and creamy.
Now consider an exotic ice cream flavor such as green tea. You may have had ice cream and green tea before, so you have reference points for both. However, your prior experiences confound your expectations of how green tea ice cream will taste and feel. Ice cream is sweet and cold; green tea is bitter and hot.
So, when choosing between chocolate or green tea ice cream, you’ll have a better model of the former. That is, your expectations of the taste of chocolate ice cream map more closely to your experience of eating it. If you’re feeling adventurous, you may pick green tea anyway. But it’s a gamble. Hence, those (obnoxiously small) free sample spoons in ice cream shops.
The primary function of information architecture is establishing meaningful distinctions. These distinctions appear as choices to users. Users understand those choices in relation to other choices (i.e., as sets of concepts) and in relation to prior interactions with similar choices (i.e., as individual concepts.)
Some of these concepts will be more obvious than others, much like chocolate is a more obvious choice of ice cream flavor than green tea. Users need help when choosing between unfamiliar or ambiguous concepts.
In other words, users need semantic analogs to those free ice cream samples. For example, each choice could include a clear label, plus an icon or a short phrase that clarifies its meaning in this particular context. Ideally, such aids give users a high-level preview of what they can expect to find when they choose that option. (I.e., they “give them a taste of what’s to come.”)
Much of the craft of IA consists of orchestrating the expectations of users as they’re inducted into new systems. This requires building nuanced bridges between users’ (imperfect) mental models and systems’ (complex, unfamiliar) conceptual models. When done successfully, a user‘s confidence in making choices will increase as he or she interacts with the system.