• Doherty Threshold

      Productivity soars when a computer and its users interact at a pace (<400ms) that ensures that neither has to wait on the other.

    • Fitts’s Law

      The time to acquire a target is a function of the distance to and size of the target.

    • Hick’s Law

      The time it takes to make a decision increases with the number and complexity of choices.

    • Jakob’s Law

      Users spend most of their time on other sites. This means that users prefer your site to work the same way as all the other sites they already know.

    • Law of Common Region

      Elements tend to be perceived into groups if they are sharing an area with a clearly defined boundary.

    • Law of Proximity

      Objects that are near, or proximate to each other, tend to be grouped together.

    • Law of Prägnanz

      People will perceive and interpret ambiguous or complex images as the simplest form possible, because it is the interpretation that requires the least cognitive effort of us.

    • Law of Similarity

      The human eye tends to perceive similar elements in a design as a complete picture, shape, or group, even if those elements are separated.

    • Miller’s Law

      The average person can only keep 7 (plus or minus 2) items in their working memory.

    • Occam’s Razor

      Among competing hypotheses that predict equally well, the one with the fewest assumptions should be selected.

    • Pareto Principle

      The Pareto principle states that, for many events, roughly 80% of the effects come from 20% of the causes.

    • Peak-End Rule

      People judge an experience largely based on how they felt at its peak and at its end, rather than the total sum or average of every moment of the experience.

    • Postel’s Law

      Be liberal in what you accept, and conservative in what you send.

    • Tesler’s Law

      Tesler's Law, also known as The Law of Conservation of Complexity, states that for any system there is a certain amount of complexity which cannot be reduced.

    • Von Restorff Effect

      The Von Restorff effect, also known as The Isolation Effect, predicts that when multiple similar objects are present, the one that differs from the rest is most likely to be remembered.

    • Zeigarnik Effect

      People remember uncompleted or interrupted tasks better than completed tasks.