Essentially, the process of interaction design involves four basic activities:

1. Identifying needs and establishing requirements.
2. Developing alternative designs that meet those requirements.
3. Building interactive versions of the designs so that they can be communicated and assessed.
4. Evaluating what is being built throughout the process.

• These activities are intended to inform one another and to be repeated. For example, measuring the usability of what has been built in terms of whether it is easy to use provides feedback that certain changes must be made or that certain requirements have not yet been met.

• Evaluating what has been built is very much at the heart of interaction design. Its focus is on ensuring that the product is usable.

• It is usually addressed through a user-centered approach to design, which, as the name suggests, seeks to involve users throughout the design process. There are many different ways of achieving this: for example, through observing users, talking to them, interviewing them, testing them using performance tasks, modeling their performance, asking them to fill in questionnaires, and even asking them to become co-designers.

• Equally important as involving users in evaluating an interactive product is understanding what people currently do. This form of research should take place before building any interactive product.

• A main reason for having a better understanding of users is that different users have different needs and interactive products need to be designed accordingly. For example, children have different expectations about how they want to learn or play from adults.

• They may find having interactive quizzes and cartoon characters helping them along to be highly motivating, whereas most adults find them annoying. Conversely, adults often like talking-heads discussions about topics, but children find them boring.

• In addition to the four basic activities of design, there are three key characteristics of the interaction design process:

1. Users should be involved through the development of the project.

2. Specific usability and user experience goals should be identified, clearly documented, and agreed upon at the beginning of the project.

3. Iteration through the four activities is inevitable.