CH. 3 Understanding Users

Human Computer Interaction

• Human-computer interaction (HCI) is a field of study focusing on the design and use of computer technology.

Understanding Users

• The agenda for the presentation includes discussing Norman's views on HCI and design, and next chapter cognition.

Donald Norman

• Donald Norman is currently with the Nielsen Norman Group.
• He was previously a professor at UCSD and worked at Apple and HP.
• The presentation material is drawn from his book "The Psychology of Everyday Things".

The Psychology of Everyday Things

• Well-designed objects are easy to interpret and understand, with visible clues to their operation.
• Poorly designed objects can be difficult and frustrating, sometimes with no clues, or even false ones.

Daily Challenges

• The presentation raises questions about how many people can effectively use various everyday devices, such as VCRs/DVD players, digital watches, copy machines, washers/dryers, stereo systems, and cell phones.

Typical Frustration

• The presentation contemplates what typical user reactions are when confronted with frustrations.

Fun Examples - "Hit any key to continue"

• This example demonstrates a common design flaw in user instructions.
• The instruction "Hit any key to continue" is problematic because keyboards don't actually have an "any" key.
• This highlights the necessity to verify that instructions are relevant and accurately reflect the physical capabilities of the system.

Fun Examples - Doors

• The presentation includes images of different doors and asks which side to push or pull. This demonstrates the importance of clear affordances in design.
• The images highlight that different cultural and design norms exist amongst different products

Fun Examples - Phones

• It raises questions about the ease of use of different phone functions, such as transferring calls, adjusting volume, and storing numbers.

Location of Controls

• This section of the presentation provides a detailed layout of controls, buttons, and features on typical telephone devices.

Psychology of Everyday Things

• Many so-called human errors and "machine misuse" are actually errors in design.
• Designers aid usability by creating effective conceptual models.
• Designers choose a specific user group as their design audience.
• Design difficulties often extend beyond the design concerns themselves.

Two Lessons

• Most human-machine system failures stem from poor design that overlooks user capabilities.
• This results in misuse and errors often attributed to the user.
• Good design always accounts for user capabilities.

Lost Sales

• Customers return products falsely claiming they are broken because of poor use or inappropriate application.
• Incorrectly missing features might lead to returns.
• Sometimes, the feature is there, but controls have been moved or changed.

Important Design Principles

• The presentation list important design aspects as affordances, visibility, constraints, mappings, feedback, and consistency.

Affordances

• Perceptual and actual features of an object showing how it can be used.
• Appearance indicates how the object should be used.

Affordance vs Mappings

• Affordances are an object's capabilities.
• Perceived affordances are what users believe objects can do.
• Signifiers act as indicators of capabilities.
• Mappings link elements of computer systems to the real world.
• Mappings are the association between a user's action and its corresponding results.

Visibility

• The visual clarity of critical components in a user interface.
• Correct parts must be visible with a relevant message.
• Should indicate necessary aspects of operation.

Visibility

• Hidden functionality leads to problems, evidenced in examples such as Tesla's high functionality relative to controls.
• Visible capabilities do not require memory and provide clear use directions.

Constraints

• Physical characteristics that limit the functionalities of an object.
• Constraint limits the possible actions which are apparent.
• It permits a variety of user possibilities.

Simple Example (Electric Plugs, Bathroom Faucets)

• Simple examples show how constraints increase ease of use.

Mappings

• Interrelationships associating two or more entities or objects
• Linking user actions with their expected outcomes.

Stove Example, Remote Example

• Illustrations demonstrate the importance of proper mapping for user understanding and ease of use.

Feedback

• Information returning from a functioning system displaying actions taken and outcomes.

Causality

• Users assume actions are directly related to results that follow immediately.
• Incorrect effects, such as unfamiliar programs causing a crash, can lead to users developing incorrect ideas about how systems work.
• Invisible consequences, like re-entering a command, may cause difficulties for users.

Other Clues

• Transfer of learned knowledge from previous experiences to new ones
• Cultural standards and stereotypes relating to design.

Transfer effects

• Transfer positive experiences from similar objects and situations to a new one (Positive transfer)
• Experiences or learning from similar objects conflict with a new situation.

Population stereotypes

• People learn and understand stereotypes relevant to design based on their environment.
• Stereotypes can differ between cultural groups in relation to design norms, such as what button to press or how to flip a switch for example.

Cultural Associations

• Users can be confused if cultural norms and the system's design differ and may lead to confusion when using systems not consistent with their experience

Designing for People

• Norman's two main principles of design:
• Provide a good conceptual model to aid user prediction of effects.
• Make aspects of the system clearly visible to aid user interpretation.

Conceptual Model

• Understanding of systems that facilitate prediction of effects of actions.
• Different users interpret systems in different ways, based on their prior experiences.
• Provides clues from affordances, contraints, and mappings.

Two Guidelines for Design

• Guide 1: Good conceptual models. This is achieved by having designer models that align with the user's conceptual models.
• Guide 2: Making systems visible. The user's actions and results are made easily apparent from the system.

Fundamental Design Goal

• Goal of design so systems should function intuitively through design alone rather than requiring user instruction to discern system functionalities.

Who Do You Design For?

• Design considerations should account for the full spectrum of user demographics.

Who do we Design for?

• Design should cater to a broad range of users (95%)
• Design should minimize harm by considering the potential 5%

Why design is hard (I, II)

• Increased complexity in the number and nature of controls (ex. car radios,displays).
• Marketplace pressures drive design priorities often favoring ease of development and cost over user experience

Individual Differences

• Designers do not accurately represent typical users in design.
• Users think and act differently based on physical and cognitive attributes and must be taken into account during design considerations

Comfort/Learning the Technology

• Reducing user anxiety by supporting rapid, incremental, and reversible actions.

Try and Try Again

• Users may require multiple tries to fully understand a new system, potentially creating frustration but impacting business.

What You Now Know

• Key cognitive principles crucial to interface design (affordances, constraints, mappings, causality, feedback, transfer effects, consistency, cultural standards, mental models, comfort)

Test your understanding of user experience design principles including affordance, visibility, and signifiers. This quiz explores common user issues and the errors related to device misuse. Challenge yourself with matching concepts to their descriptions in the context of everyday devices.