User-Centered Design (UCD) and Activity-Centered Design (ACD)

There are many types of design methodologies: Behavior-Centered Design, Task-Centered Design, Goal-Directed Design, etc. However the two most popular methods are User-Centered Design and Activity-Centered Design. The key goal of all of these methodologies is to create a usable, efficient, effective design. Each method has its own unique approach for creating the design.

User-Centered Design (UCD), also called Human-Centered Design, is a methodology that centers design efforts around the user. The process starts by defining who the users are including their characteristics, demographics, preferences, etc. with documents such as personas. Next, the users’ needs are analyzed through methods such as surveys, interviews, card sorting, etc. Finally a design is created and iterated based on those wants and needs. The most important aspect to this type of design is to know your users. The goal is to create a way for users to complete tasks or activities in a way that is almost completely customized to their preferences, wants and needs.

User-Centered Design has many critics however, which say that tailoring a product for a specific set of users is too niche and will make the design weaker and less usable for everyone else. UCD also puts too much focus on the users, and not enough focus on the activity at hand. While it is important to listen to users, it is a good designer’s job to know when diverse user requests warrant further investigation, and when they are simply bells and whistles. Implementing unfiltered user suggestions can compromise or complicate the quality of the design.

Many things have been created without focus on the user, but by instead focusing on the intended activity for the product. This is called Activity-Centered Design (ACD). For example: cameras, garden tools, kitchen utensils, automobiles, etc. When the product is built to accomplish an activity or set of activities well, users will learn to adapt to the product and the product will work for the majority of users. In ACD, like in most methodologies, the designs are continually iterated and improved based on feedback from users and personal experiences.

The Activity-Centered Design method focuses on the activity as the highest level of the design. The activity is then made up of tasks, of which each task has one or more actions, and each action has one or more operations. This is called the “Activity Theory”. Robert Hoekman Jr coined a document for identifying activities in a system called the Activity Grid, which outlines all of the activities and their subsidiary parts based on this theory. An example of the Activity Theory can be seen below with the activity of listening to music in the car:

  • Activity: Listen to music while driving
  • Tasks:  Choose a Radio Station, Play a CD, Listen to an IPod play list
  • Actions: (Choose a radio station) Start the radio, scan for stations
  • Operations: (Scan for Stations) Press the Scan button on the radio once.

Regardless of the methodology you choose, it is important to remember to remain flexible. A design methodology is not a strict set of rules, but merely a guideline for creating a design. Each methodology will have its own strengths and weaknesses and no one method will be the sole contributor to success. It is up to the designer to iterate and improve not only their design, but their chosen methodology. Each individual must create a balanced method that will work for them, based on the constraints and needs of the design challenges at hand.

1. Don Norman’s Essay: Human Design Considered Harmful
2. Robert Hoekman Jr’s Article on Peachpit entitled: Redefining User-Centered Design