Introduction to Human–Computer Interaction

• Introduction
• Human Computer Interaction (HCI) definition
• The importance and scope of HCI
• The evolution of HCI
• The process of Interaction Design
• Usability
• User experience (UX)
• Design principles

Based on material from:

Sharp, H., Preece, J. and Rogers, Y.(2019). Interaction Design Beyond Human-Computer Interaction. 5th Ed. Sussex: John Wiley & Sons Ltd.

• Define HCI
• Explain the importance and scope of HCI
• Discuss the evolution of HCI
• Describe usability in HCI
• Explain the process of interaction design, design principles

How many interactive products are there in

everyday use?

(Think for a minute about what you use in a typical day)

How many are actually easy, effortless and

enjoyable to use?

• Need to push button first to activate reader
• Normally insert bill first before making selection
• Contravenes well known convention

Dix: “HCI is study of people, computer technology and the ways these influence each other. We study HCI to determine how we can make this computer technology more usable by people” (1998) Carroll: “HCI is the study and practice of usability. It is about understanding and creating software and other technology that people will want to use, will be able to use, and will find effective when used. ” (2002)

• Usability evaluation
  • Observing users; testing and modeling users; expert evaluations
• Interaction styles
  • Virtual environments; Menus and forms; Commands and natural language; hands-free input
• Interaction devices
  • Keyboards; Pointing devices; Speech I/O; Image and video I/O; other sensory devices; Mobile devices

• Large number of ID consultancies, examples of well known ones include:
  • Nielsen Norman Group: “help companies enter the age of the consumer, designing human-centered products and services”
  • Cooper: “From research and product to goal - related design”
  • IDEO: “creates products, services and environments for companies pioneering new ways to provide value to their customers”

• Whether someone is disabled changes over time with age, or recovery from an accident
• The severity and impact of an impairment can vary over the course of a day or in different environmental conditions
• Disabilities can result because technologies are designed to necessitate a certain type of interaction that is impossible for someone with an impairment

• Generalizable abstractions for thinking about different aspects of design
• The do’s and don’ts of interaction design
• What to provide and what not to provide at the interface
• Derived from a mix of theory-based knowledge, experience and common-sense

1. Visibility (cont)

• What happens if there is more than one command starting with the same letter?
  • e.g. save, spelling, select, style
• Have to find other initials or combinations of keys, thereby breaking the consistency rule
  • e.g. ctrl+S, ctrl+Sp, ctrl+shift+L
• Increases learning burden on user, making them more prone to errors

• Internal consistency refers to designing operations to behave the same within an application
  • Difficult to achieve with complex interfaces
• External consistency refers to designing operations, interfaces, etc., to be the same across applications and devices
  • Very rarely the case, based on different designer’s preference

• Interaction design is concerned with designing interactive products to support how people communicate and interact in their everyday and working lives
• It is concerned with how to create quality user experiences for services, devices and interactive products
• It is multidisciplinary, involving many inputs from wide-reaching disciplines and fields
• Optimizing the interaction between users and interactive products requires consideration of a number of interdependent factors, including context of use, types of activity, UX goals, accessibility, cultural differences, and user groups.
• Design principles, such as feedback and simplicity, are useful heuristics for informing, analyzing, and evaluating aspects of an interactive product.