ABSTRACT
Products for which a high setting could be dangerous should start up slow and then require deliberate user action to switch to a higher power level. Products that can cause sensory and physical strain should give people a chance to transition to the higher state of engagement—to get up to speed, so to speak. Treadmills are a good example of a product that starts slow to prevent accidents. The principle of starting “slow and low” can also help adapt products to users’ personal differences, which might vary greatly across user populations or over the course of a given user’s experience with the product. Some continuous positive airway pressure devices, which treat sleep apnea, slowly increase airway pressure over time so that new users become accustomed to the sensation of air moving into their windpipes. Many products require training, and in some cases, users continually progress toward using more complex and powerful features or even versions of such products.
