Human-centered design (HCD) is a term product creators use to describe a process of designing for people. HCD develops solutions to problems by involving the human perspective in all steps of the problem-solving process.

Below are the four fundamental principles of HCD. The principles are based on Don Normal talk on HCD.

1. Focus upon the people

Whatever you design, always thinking of people who'll use your product. Those people are not abstract 'users' those are real human beings who will interact with your product. Keep in mind that your product is just a tool that helps them reach their goal.

It's vital to identify the real goal of real people who will use your product.

The process of identification starts with a simple question: who am I building this for? Unless you're building a product for yourself, you have to start by thinking about your audience:

• Who will be using this product?
• In what context (time, place, device, etc.) will it most likely happen?

After you define your target users you'll need to figure out critical user journeys. A tool called the job to be done (JTBD) framework can help you with that.

When _____ , I want to _____ , so I can _____ .

This framework provides an excellent way to identify critical user journeys and map them to possible solutions.

#2. Find the right problem Not all problems worth solving. Don Norman identifies two types of problems - fundamental problems and symptoms of the problem. He argues that it's essential to solve a fundamental problem first because by doing that you'll solve a root cause of other problems.  Of course, conducting research and identifying fundamental problem requires time and product teams often argue that they don't have enough time. But no matter how much time it takes, the process of identification of core problems should be an inalienable part of the design process. When designers skip this part it could lead to a situation when designers try to solve the wrong problems. 

Thus, think of this activity as an investment:

The better you conduct a research, the more time and energy you save down the road.

3. Think of everything as a system

Don't focus solely only on one part of a user journey (local experience) while forgetting about other parts of a journey. Improving the local experience doesn't mean that you'll have a good overall user experience. Always think about the big picture - what you want to achieve with your experience, what is the final result you care about.

Imagine an e-commerce app that has a really smooth user flow for product purchase but as soon as customers reach customer support service (i.e. try to return an item they purchased recently), they face slow response rates. No matter how good a product purchase experience is, the overall user experience won't be really good.

Users should have good user experience at all touchpoints, both digital and physical.

4. Always test your design decisions

No matter how much time you spend on ideating and prototyping your design solution, you should always test it with real people. The feedback from the testing session will help you understand what part of your design requires improvements.

You can't replace testing with real users with testing with your family/team members/stakeholders because such testing won't be representative. Designers, developers, and even UX researchers often suffer from the false-consensus effect - people have a tendency to assume that others share their beliefs and will behave similarly in a given context. In other words, product creators assume that people who will use a product they created are like them. Let's say it once again:

You are not the user

That's why only studying with your actual target users will provide valuable insights.

Conclusions

The great thing about the principles mentioned above is that they apply even if you don't follow the process of human-centered design.