User control and freedom is the principle that people will take many paths through an interface (not always the intended ones), and so wherever they end up, they should be able to return to where they came from or change their mind. The notions of “Cancel” and “Undo” are the best examples of user control and freedom: they allow users to change their mind if they ended up in a state they didn’t want to be in. The dialog below is a major violation of this principle; it gives all of the power to the computer:

The same applies if a participant asks you questions: you can’t answer them, because you wouldn’t normally be there to help. The design should do the teaching.

The Google search page actually accepts many other implicit inputs too. There are a variety of personalization settings, such as search history, search preferences, and even sensor input (such as your location) that it also accepts as input. The user interface doesn’t provide explicit controls for providing this input, but it is user input nonetheless. These implicit inputs contain issues of justice. For example, what harms may come by Google tracking your location when you search? For many, no harm, but what about people do not secure their accounts, and might be stalked by a violent ex, or someone in witness protection?

The fastest and easiest form of prototype is a sketch, which is a low-fidelity prototype that’s created by hand. See the drawing at the top of this page? That’s a sketch. Get good at using your hands to draw things that you want to create so that you can see them, communicate them, and evaluate them. With enough skill, people can sketch anything, and they almost always do it faster than in any other media. On the other hand, because they have the least detail of any prototype (making them low-fidelity), they’re most useful at the beginning of a design process.

User experiences can be evaluated with qualitative and/or quantitative measures. Your decision of qualitative and/or quantitative presentation of your findings may depend on the type of data captured, who will be viewing your research, and whether qualitative or quantitative data will be easier to understand.

An example of a contrast effect can be seen in a Pew Research Center poll conducted in October 2003, a dozen years before same-sex marriage was legalized in the U.S. That poll found that people were more likely to favor allowing gays and lesbians to enter into legal agreements that give them the same rights as married couples when this question was asked after one about whether they favored or opposed allowing gays and lesbians to marry (45% favored legal agreements when asked after the marriage question, but 37% favored legal agreements without the immediate preceding context of a question about same-sex marriage). Responses to the question about same-sex marriage, meanwhile, were not significantly affected by its placement before or after the legal agreements question.

There are several things to notice about the exchange above. It’s respectful, with each person listening and accepting what the other person is saying. It’s collaborative, with each person contributing knowledge to the conversation. It’s grounded in design rationale and design judgement, focusing on why choices are made and why different choices were made, and how that might effect the success of the solution.

However, most societies do not value creative thinking and so our skills in generating ideas rapidly atrophies, as we do not practice it, and instead actively learn to suppress it1

Some design scholars are skeptical about human-centered design because they don’t believe modeling and verifying people’s needs through a few focused encounters is sufficient to actually address people’s problems, or systems of activities1212 Norman, D. A. (2005). Human-centered design considered harmful. ACM interactions. . These and other critiques lead to a notion of participatory design 1010 Muller, M. J., & Kuhn, S. (1993). Participatory design. Communications of the ACM. , in which designers not only try to understand the problems of stakeholders, but recruiting stakeholders onto the design team as full participants of a design process. This way, the people you’re designing for are always represented throughout the design process. The key challenge of participatory design is finding stakeholders that can adequately represent a community’s needs, while also participating meaningfully in a design process.

Capturing these models of problems is essential in design contexts where designers are separate from stakeholders; the models can act as a form of boundary object22 Barrett, M., and Oborn, E. (2010). Boundary object use in cross-cultural software development teams. Human Relations. , helping designers work with other people, like developers, product managers, project managers, marketers, and others to understand who is being helped and why. But from a design justice perspective, one might wonder what the value of articulating a persona, scenario, or problem statement in words is. Wouldn’t everyone in the community you’re servicing understand these problems intuitively, from their lived experience? Even in a community, everyone is different: coming to agreement on who is being served, why they are being served, and what one believes is causing the problem, and how it impacts a particular group, is key to focusing design efforts.

hat means that problems are inherently tied to specific groups of people that wish their situation was different. Therefore, you can’t define a problem without being very explicit about whose problem you’re addressing. And this requires more than just choosing a particular category of people (“Children! Students! The elderly!”), which is fraught with harmful stereotypes. It requires taking quite seriously the question of who are you trying to help and why, and what kind of help do they really need? And if you haven’t talked to the people you’re trying to help, then how could you possibly know what their problems are, or how to help them with design?

Given all of these skills, and the immense challenges of enacting them in ways that are just, inclusive, anti-sexist, anti-racist, and anti-ableist, how can one ever hope to learn to be a great designer? Ultimately, design requires practice. And specifically, deliberate practice33 Ericsson, K. A., Krampe, R. T., & Tesch-Ršmer, C. (1993). The role of deliberate practice in the acquisition of expert performance. Psychological Review. . You must design a lot with many stakeholders, in many contexts, and get a lot of feedback throughout.