As users gain experience with using a product, their skill tends to improve in the following ways:
- Increasing knowledge of the product’s capabilities (what it can do)
- Increasing knowledge of how to perform tasks, and how to deal with special cases
- Increasing speed
- Decreasing error rate
- Increasing confidence
In general, one might also expect the quality of the work done to increase as well. But the quality of work is difficult to define and measure. For rote, repetitive, mechanical work, simply getting the work done quickly and with few errors makes it high-quality work, and so more practice will almost always lead to better quality work. For creative tasks, not only is judging quality a very subjective and inherently unmeasurable affair, but also more practice will not necessarily guarantee better quality work. If someone’s a bad artist with no visual design sense, then if learning and becoming competent with Photoshop’s features will not necessary make his artwork more visually appealing.
Practice
The most reliable way to get better at something is to practice — that is, to repeatedly perform (or rehearse the performance of) a task.
In some situations, practice “just happens” — you may have a job where you have to do some activity repeatedly, and so you gain practice and thereby get better at the activity because it’s just a part of your work. Card et al. (1983, p. 188) observe that “people generally become skilled in whatever becomes routine for them.”
But if you are intentionally practicing with focused attention, having in mind the specific goal of improving your skill, and challenging yourself to work at increasing levels of difficulty, you can be said to be engaging in deliberate practice. Deliberate practice also involves carefully monitoring and evaluating your own work and actively seeking out ways to improve it.
As users gain experience with an activity through repetitive practice, their performance improves rapidly at first, but the rate of improvement gradually slows down until a peak performance level is reached.
For most tasks, the average time taken to complete the task declines with practice in this way, and the Power Law of Practice is a mathematical description of this effect, verified by psychological experiments. The Power Law of Practice can be illustrated graphically with the following illustration:
Power Law of Practice
Power Law relationships may or may not apply to other quality metrics besides task completion time. According to Card et al. (1983, p. 59), the Power Law of Practice applies to most mechanical (“sensory-motor”) and cognitive skills, but does not apply to learning in the sense of knowledge acquisition.
Skills atrophy
Without continual ongoing practice, skills will gradually tend to atrophy or “fade” over time. In general, motor skills (like riding a bicycle) do not atrophy as quickly as knowledge-based skills (like long division). But atrophied skills can be refreshed and improved again with revision and practice.
Attaining competence
Another useful model of how people improve at an activity is the Four Stages of Competence model. According to this model, a user goes through the following stages in mastering a skill:
- Unconscious incompetence: The user is unaware of how bad he is at the skill (and may even be completely unaware of the skill).
- Conscious incompetence: When attempting the skill, the user gradually becomes aware of his deficiency in the skill area. The user realizes that he will have to learn and practice to improve at the skill, and this can sometimes be a overwhelming and daunting realization.
- Conscious competence: By means of practice, the user becomes able to perform the activity competently but slowly. Perfoming the activity requires a lot of concentration, focus, and effort.
- Unconscious competence: The user is able to do the activity effortlessly, naturally, automatically, and quickly without consciously thinking about it. The skill has become “second nature”.
To better understand these stages, you might try thinking back to your personal experiences of learning to drive an automobile. You probably went through these four stages, and today you are probably so “unconsciously competent” that you can do other things — like eating, or singing along to songs on the radio — while driving.
Judging competence
If you are conducting usability studies or questionnaire surveys, you should be aware that people tend to be very poor judges of their own competence. People who are incompetent at a particular activity tend to grossly overestimate their level of skill, and additionally are not very adept at judging the skill levels of those who are more competent. Conversely, many experts, often because they are acutely aware of how much they still do not know, tend to underestimate their own level of skill. This phenomenon is known as the Dunning-Kruger effect.
Teaching skills to users must include practice
Simply telling or showing someone how to do something is rarely sufficient. Training or education has to include hands-on practice for it to be effective.
