User Centered Design Notes

User-Centered Design (UCD)

User-centered design (UCD) is a design philosophy that prioritizes the needs, wants, and limitations of end-users throughout the entire design cycle. It emphasizes understanding how users will interact with a product, service, or system to ensure its success.

Key Elements of Successful Design

According to UCD, the three essential elements for a successful design are:

  • Usefulness: Does the design enable users to achieve their goals?
  • Usability: Can users employ the design effectively, efficiently, and consistently?
  • Desirability: Do users want to use the design?

This concept is often visualized as a "three-legged stool," where the absence of any leg causes the entire structure to collapse. Ultimately, users determine whether a product meets these criteria, highlighting the importance of user involvement in the design process.

User Involvement

UCD emphasizes involving users throughout the design process, from the earliest stages of product development to launch. Designers immerse themselves in the user's environment to understand the context in which the product will be used. This approach, also known as empathetic design, goes beyond traditional market research by fostering constant communication with a smaller group of users and observing their interactions with products in their natural settings.

Key Ideas Guiding UCD

The core principles driving UCD include:

  • Understanding Users, Tasks, and Environments: Designs must be based on a thorough understanding of users, their tasks, and the environments in which the product will be used.
  • User Involvement Throughout Design and Development: Users are actively involved in research, design, and testing phases.
  • User-Centered Evaluation: User feedback guides design refinements and changes.
  • Iterative Process: Designs undergo multiple rounds of development based on user interactions, ensuring continuous improvement until launch.
  • Holistic User Experience: Designs consider the entire user experience, from initial exposure to disposal or repair, not just the immediate interaction with the product.
  • Multidisciplinary Teams: Design teams include diverse skills and perspectives, such as anthropologists, ethnographers, and psychologists, to provide a comprehensive understanding of users.

Designer Knowledge

To make informed decisions, designers need to consider:

  • Who are the users of the product?
  • What are the users’ tasks and goals?
  • What are the users’ experiences and expertise with the product and products like it?
  • What functionality do the users require of the product?
  • What other stakeholders will be impacted by the product?
  • Why is the product being developed?
  • What are the overall objectives?
  • How will the product be used?
  • How will it be judged a success?
  • What are the technical and environmental constraints?
  • What functionality is needed by users?
  • What are the typical scenarios of how and why users will use the product?
  • How important is ease of use and ease of learning?
  • How long should it take users to complete their tasks?
  • Is it important to minimize user errors?

Multidisciplinary Teams in UCD

UCD teams are multidisciplinary, encompassing roles such as:

  • Anthropology: The study of humans within society, including cultural, biological, and linguistic aspects.
  • Ethnography: A branch of anthropology focusing on specific cultures and customs.
  • Psychology: The study of the mind and behavior.

Inclusive Design

UCD can highlight accessibility issues for individuals with physical, sensory, perceptual, or other challenges. Inclusive design aims to create mainstream products and services accessible and usable by as many people as possible without specialized adaptations.

Inclusive design is defined as “The design of mainstream products and/or services so that they are accessible and usable by as many people as possible without the need for adaptation or specialised design”.

UCD Stages

The user centered design process includes these stages:

  1. Research:
    • User Personas and Scenarios
    • Context Studies
    • Focus Groups
    • Competitor Comparison
    • In-depth Interviews
    • Questionnaires
    • User Goals
    • Usability Goals
  2. Concept:
    • Usage Scenarios
    • Brainstorm Ideas
    • Concept Models (e.g., sketches)
    • Paper Prototypes
    • Usability Testing
    • Expert Evaluation
  3. Design:
    • Expert Evaluation
    • Product Structure Diagram
    • Process Flows
    • Prototypes
    • Card Sorting
    • Usability Testing
    • Accessibility Evaluation
  4. Implementation:
    • Accessibility Evaluation
    • Usability Testing
    • Expert Evaluation
  5. Launch:
    • Usability Testing
    • Expert Evaluation
    • Accessibility Evaluation
    • Focus Groups
    • Competitor Comparison
    • Metrics (evaluating sales data)

Usability

Usability refers to the extent to which a product can be used by specified users to achieve specific goals effectively and efficiently, while functioning predictably and consistently.

Key Aspects of Usability

  • Effectiveness: Achieving goals completely and accurately.
  • Efficiency: Achieving goals quickly and with minimal effort.

A usable product is intuitive, pleasant, satisfying, and tolerant of user errors.

User-Product Interfaces

The point where a user interacts with a product is known as the user-product interface. Effective mapping of this interface involves:

  • Simplicity: Avoiding unnecessary complexity.
  • Ease of Use: Being self-explanatory.
  • Intuitive Logic: Functioning as expected.
  • Organization: Placing elements in the most effective locations.
  • Low Memory Burden: Requiring minimal memorization.
  • Visibility: Making important features easily noticeable.
  • Feedback: Communicating important information to the user.
  • Affordance: Designing elements to suggest their use (e.g., buttons afford pushing, knobs afford turning).

Usability Objectives

When designing for usability, target the following objectives:

  • Usefulness: Serving a purpose that users need.
  • Effectiveness: Performing its intended function well.
  • Learnability: Being easy to learn or intuitive to use.
  • Likeability: Being appealing to users.

Enhanced Usability

A design prioritizing usability can achieve enhanced usability, resulting in:

  • Product Acceptance: Higher likelihood of acceptance.
  • Positive User Experience: More enjoyable user interaction.
  • Productivity: Increased user output in the same amount of time.
  • Reduced User Error: Fewer operational mistakes.
  • Minimized Training and Support: Less user instruction required.

Population Stereotypes

Population stereotypes are widespread responses within a user population. For example, using a tap with a red symbol for hot water or tightening screws by turning them right.

Advantages:
  • Reduced errors during use.
  • Easy understanding of how to use the product.
  • Less to remember while using the product.
Disadvantages:
  • Cultural differences can lead to misunderstandings.

Strategies for User Research

Effective user research involves understanding user populations and their needs.

User Population

User population refers to the range of users for a specific product or system. Products may be designed for particular user populations or multiple populations.

Classification of Users

User populations can be classified based on characteristics such as age, gender, and physical condition. This classification facilitates gathering detailed feedback tailored to each group. For example, older users with arthritis may have different concerns regarding a product's design compared to student users.

Personae, Secondary Personae, and Anti-Personae

Designers can create fictional characters, called personae, secondary personae and anti-personae, through observation and interviews, to predict user responses and interactions with the product. Types of Personae:

  • Personae: Typical stakeholders and primary users.
  • Secondary Personae: Users who are not the primary target audience but whose needs the product should meet.
  • Anti-Personae: Individuals for whom the product is not intended.

Scenarios

Scenarios are imagined sequences of events in a person's daily life, based on researcher assumptions. It is important to consider worst, average and best case scenarios.

Use Case

A use case focuses on a specific action and formulates possible sequences of interactions or event steps between a user and a product to achieve a particular action.

Strategies for UCD

A clear UCD strategy improves acceptability and usability while reducing costs and effort and fulfilling user requirements.

Field Research

Field research involves firsthand observation of a customer's user experience in their environment. This can highlight:

  • How effective the product is
  • How the environment affects the product and its use
  • Errors the user might make when using the product
  • Frustrations the user might have with the product
  • How it affects secondary users

Method of Extremes

The method of extremes tests product functionality by using individuals representing the extremes of the user population, typically the 2.5th and 97.5th percentile.

Observation, Interviews, and Focus Groups

  • Observation: Collecting data from users as they interact with the product.
  • Interviews/Questionnaires: Gathering feedback from users through spoken or written questions.
  • Focus Groups: Discussing the product with a group of users.

Affinity Diagramming

Affinity diagramming organizes ideas and information into similar groups. This is especially useful for hours of user feedback and responses.

Participatory Design, Prototype and Usability Testing Sessions

  • Participatory design: When users representing the target market for a product perform realistic tasks by interacting with a paper version of the user-product interface manipulated by a person acting as a computer who does not explain how the interface works.
  • Prototype testing session: A session where a test product is made and tested - all experiments are conducted before making the final product, making all changes necessary that can be seen when the prototypes are used.
  • Usability testing session: Testing a product with potential users to find out how usable the product is.

Natural Environments vs. Usability Laboratories

Natural Environments
Advantages
  • Observing the effect of the environment on the user.
  • User behavior is more natural.
Disadvantages
  • Limited testing equipment compared to a lab.
Usability Laboratories
Advantages
  • Larger range of equipment.
  • More control over the environment.
Disadvantages
  • User behavior is less natural.
  • Users are aware of being tested.
  • Expensive to use.

Beyond Usability—Designing for Pleasure and Emotion

Design for emotion is a design strategy that focuses on increasing user engagement, loyalty, and satisfaction by incorporating emotion and personality into product design. Designers consider emotions such as fear, excitement, relief, ego, and love.

The Four-Pleasure Framework

The four-pleasure framework includes:

  • Socio-pleasure: Deriving pleasure from social interaction.
  • Physio-pleasure: Deriving pleasure from the feel, taste, or smell of a product.
  • Psycho-pleasure: Deriving pleasure from the cognitive demands of using a product or service.
  • Ideo-pleasure: Deriving pleasure from products that appeal to consumer values.

The Attract/Converse/Transact (ACT) Model

The Attract/Converse/Transact (ACT) model is a framework for creating designs that improve the relations of users with a product and intentionally trigger emotional responses.

  • Attract: Aesthetics-oriented.
  • Converse: Interaction-oriented.
  • Transact: Function-oriented.