Interactive products have become ubiquitous companions of all facets of everyday life. In human-computer interaction research, these changes are reflected in a shift away from investigating how to make task-related interaction more effective and efficient towards finding out how interaction can happen in a more joyous and satisfying way. Source.
The purpose of the system should be clear. The system has to fulfill, or even better exceed, user's expectations.
1a. The system should be designed with the right affordances to explicitly tell users its purpose(s).
1b. The system must be functional, meaning that it must fulfill the purposes highlighted by the affordances and meet users’ expectations.
1c. Additional features (other than the core ones) are welcome, even better if they foresee possible alternative uses of the system: a product that is actually exceeding users’ expectations is often a predictor of a good user experience.
The user-system interaction should be sustained through steady, prompt and unobtrusive feedback.
2a. The system should provide steady and prompt feedback.
2b. The feedback should be as less obtrusive as possible.
2c. The “obtrusiveness” of the feedback should be proportional to the level of priority (to establish a sort of hierarchy).
The system should be simple and intuitive in its use; it should facilitate user concentration on the task at hand by providing meaningful feedback and avoiding non-relevant distractions.
3a. The system must be usable.
3b. The system should provide feedback that is relevant and meaningful for the task at hand.
3c. The system should avoid distractions, namely stimuli that are not relevant for the task at hand.
The system should almost disappear, be transparent, while used to allow users to focus on the activity and to engage in the experience.
4a. The system should be ergonomic, it should fit users’ skills and activity purposes.
4b. The system behavior should be consistent and predictable.
4c. The system should be designed with aesthetic integrity, in other words the design should be visually appealing and common principles of good design should be followed: it should also provide a graceful flow, namely the interaction between users and the system should be smooth and graceful.
Users should be allowed to customize and manipulate the system according to their peculiarities and preferences, to feel familiar with the system, as if the system was tailored specifically for them.
5a. The system should be, to a certain extent, customizable and manipulable by users in both its appearance and its functionality.
5b. The customization process should be easily accessible, and with a predictable outcome.
5c. Provide users with multiple choices for interacting with the system (doing the same activity in many different ways).
The system should adapt to the user in that it should be designed to dynamically provide adequate challenges for both novice, average and experienced users.
6a. The system should have a steep learning curve to help novice users.
6b. The system should encourage users to explore it and to discover all the features and opportunities for interaction.
6c. The system should provide advanced features or extra functions (e.g. accelerators, macros, advanced settings, etc.) and make them accessible for intermediate/advanced users.
The system should make users feel “free” of constraints and, at the same time, in control of the experience.
7a. The system should help users to improve their skills and to reduce the margin of error in performing the activity.
7b. The system should not make users feel trapped. Avoid (as far as possible) constraining users’ actions, provide them an exit strategy and make the actions easily reversible.
7c. Users should be always allowed to enable or disable automatic processes or system aids.
The pace of the system should adapt to the user and to the rhythm of the experience.
8a. The system’s pace should be suitable for the activity for which it was designed.
8b. The experience should not be interrupted by the system but users should be allowed to suspend the interaction and to restart it from the point of achievement he reached.
8c. Users should be allowed to speed up or slow down the rhythm of the interaction.
The system should help users to fulfill the motivations behind its use and to satisfy basic psychological needs.
9a. The system should be designed by looking at final users and the activity they seek to accomplish, this means that you should know them first.
9b. Knowing all the possible users and activities is impossible, so the system should be flexible in order to adapt to various users for various activities and in different contexts.
9c. When applicable, the system should help users to satisfy the three basic psychological needs (in a broad sense): need for competence, autonomy, and relatedness.
The system should be innovative (and conservative at the same time).
10a. The system should provide a certain degree of novelty and variety to users.
10b. The system should be the result of a trade off between innovation and tradition, where tradition is meant as consistency with familiar systems and compliance to standards.
10c. The system should ensure interoperability to seamlessly integrate into the existing content.