COMP3511 - Human Computer Interaction

Human Computer Interaction is all about understanding the design, implementation and evaluation of interactive systems that considers the users at every stage of the process.

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1. Framework for Evaluation

This topic covers all the elements you should consider in analysing and evalutating and interface or design.

1.1. Some basic ideas

Goals and Tasks

To evaluate an interface, we must think of what goals a user wants to achieve. In order to achieve these goals users may have to carry out tasks (steps) to reach the goal.

What is interaction design

Interaction design is all about making usable products. Usable here means:

• Easy to learn
• Effective to use
• Provides an enjoyable experience We also aim to optimise user interaction with the system or product so that they support and extend the user’s activities in effective useful and usable ways

The process of interaction design follows the same process of any design development:

• Establishing requirements
• Developing alternatives
• Prototyping
• Evaluating With the steps repeated enough times as necessary until the design meets the requirements set.

1.2. Usability Goals

These are what you should check in terms of usability for an interface:

• Effective
  • How well does a product do what it’s supposed to do?
  • Does it help people achieve their goals?
• Efficiency
  • Does it help people achieve their goals with minimal steps?
  • Does it have unnecessary tasks that are more “system related” rather than through a natural method?
• Safety
  • Doesn’t kill or injure people
  • Helps avoid mistakes
  • Doesn’t delete important information
  • Undo provided
• Utility
  • Does the product have all the functions that the user needs to achieve the goals?
• Learnability
  • Is the system easy to use?
  • Can the user start using it with minimal confusion / cognitive load
  • Doesn’t take long to be productive
  • Similar tasks have similar interactions
• Memorability
  • Is it easy to forget how to use the system?
  • How often do people use the system?

1.3. Design principles

Design principles are generalizable abstractions for thinking about different aspects and elements of design.

• Visibility
  • Helps the user understand what to do with the system
  • The visual design provides clues about how to interact with the system
• Feedback
  • The way the system reacts to the user input, sending a signal back to the user
  • Can be visual or auditory
• Constraints
  • Physical
    • Keys can only be inserted in a specific orientation
  • Semantic
    • Some things just make sense, and some things don’t
    • Requires that we have knowledge of the real world and can translate those relations to the system
  • Cultural
    • Socically acceptable behaviour in one society could differ from another society
    • localised products might work in a particular way
  • Logical
    • exploits people’s everyday common sense and logical reasoning
• Natural mappings
  • Spatial relationship between controls and the outcome
  • Layout and physical design

1.4. Usability Principles (Heuristics)

• Visibility of system status
  • To do with feedback
  • Keep the user informed
  • Show what the system is doing
• Match between system and the real world
  • Avoid system-oriented jargon
  • Familiar concepts to the user
• User control and freedom
  • Actions are not taking place in unpredictable, automatic ways
  • The user needs to be in control as much of possibles
• Consistency and standards
  • Helps users understand what could do since they can build knowledge they have acquired elsewhere
  • Actions or sequences of actions are conducted in the same manner
• Help and Documentation
  • Information that can be easily accessed and searched
• Help users recognise, diagnose and recover from errors
  • Error messages are presented using plain language that the user can understand
  • The error is described and a solution is presented
• Error prevention
  • Stop errors from occurring in the first place
  • Providing clear labelling or meaningful terminology
• Recognition rather than recall
  • Relying on being able to easily recognise options
  • Not relying on memorisation of sequences, commands and ideas
• Flexibility and efficiency of use
  • Experienced users want to carry out their tasks efficiently
  • Provide alternative ways/paths to cater for both experienced and inexperienced users
  • Accelerators not visibile to the novice user but provide efficiency for the expert
• Aesthetic and minimalist design
  • Avoid providing information that is irrelevant or rarely needed.
  • Reduce the number of steps needed to achieve important goals

1.5. User Experience (UX)

User experience is all about the v i b e

1.6. Think aloud protocol

The think aloud protocol is an observation technique used to evaluate an interface by verbalising the thoughts a user has as they interact with the interface. The aim is to gather a lot of user comments about the interactions and understand where the good interactions happen and where the pain points are.

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2. Design Process: Idea to Scenarios

This topic covers the process of going from an idea to getting ready to build your first prototype

2.1. Product Description Statement

The product description statment is a short summary that describes what the product will do to meeet the user goals. It should be around 30 words or less. For example:

This app aims to allow students to write notes for their classes in a “gamified” way to encourage good study habits.

The aim of the product description statement is to condense the entire idea to a single or simplified focus, so that it can be relied on in the evaluation stages to see if the product meets the description.

2.2. Stakeholders

There are a range of people involved in the process that can be referred to as stakeholders

• Direct users (primary)
  • Usually the target audience for the interface
• Indirect users (secondary)
  • Those who manage direct users
  • Those who receive output from the product
• Other stakeholders (tertiary)
• Don’t include facilitating stakeholders (Designers)

2.3. Data Gathering

The point of data gathering is about knowing what users want, how they interact with existing systems, and understanding what changes or new features need to be developed.

Data gathering is generally done through the following:

• Questionnaires
• Interviews
• Focus groups and workshops
• Naturalistic observation
• Studying documentation

2.4. Personas

After you’ve gathered, organised and analysed your data you will gain and understanding of the user’s point of view. This will allow you to develop personas. There are two broad types of personas:

• Marketing-targeted personas - that model purchase motivations
• Interactive personas - that model usage behaviours

Personas usually have a list of information to flesh out their character:

• Personal
  • Name
  • Age
  • Gender
  • Photo
  • Ability/Disability
• Professional
  • Education
  • Professional background
• Technical
  • Goals
  • Computer literacy
  • Technology they use to access interface

2.5. Scenarios

A scenario is a contextual narrative based on the findings of your data gathering and analysis featuring your personas. These scenarios and goal-directed and should outline the tasks that the persona carries out as they achieve their goals.

• Think aloud protocol
• Product desicription statement
• Stakeholders and users
• Data gathering
• Personas
• Scenarios
• Diagrammatic Techniques