Unit - 1

Introduction

1.1 What is HCI?

• The term human–computer interaction (HCI) is used widespread since early 1980s.
• Second World War provided impetus for studying the interaction between humans and machines, as each side tried to produce more effective weapons systems
• This led to wave of interest in area among researchers
• As computer use became more widespread, researchers studying interaction between people and computers with psychological, physical and theoretical aspects .
• Originally known as man–machine interaction
• Later it became human–computer interaction in recognition of particular interest in computers and composition of user population
• Study of how people use computers throughout their life
• HCI draws on many disciplines, but it is in central concern in computer science and systems design
• For all other disciplines it can be specialism but for system design it is an essential part of design process
• From this perspective, HCI involves design, implementation and evaluation of interactive systems in the context of user’s task and work
• When we talk about human–computer interaction, we do not necessarily imagine single user with a desktop computer
• A user can be an individual user, a group of users working together, or a sequence of users in an organization, each dealing with some part of the task or process.
• The user is whoever is trying to get the job done using the technology
• A computer can be any technology ranging from general desktop to large-scale computer system, process control system or embedded system
• System may include non-computerized parts, including other people
• An interaction can be any communication between a user and computer, direct or indirect.

1.2 Discipline involved in HCI

1.3 Why HCI is important?

• Human have limited capacity to process the information so multitasking comes in picture
• HCI includes the design stage which involves studying the principles of human behavior
• In this modern era, technological systems are an integral part of our daily lives
• So it’s important to understand & learn how design of particular system can affect perception, behavior
• By correctly designing interfaces, efficiency can be improve and effectively while improving user satisfaction and reduce errors.

1.4 Psychology of Everyday Things

•         Many so-called human errors are actually errors in design

•         Human factors became important in WW-II due to human performance limitations being reached when handling complex machinery

•         important concepts for designing everyday things are

      affordances

      Causality

      visible constraints

      mapping

      transfer effects

      population stereotypes

      conceptual models

      individual differences

      why design is hard

• Making things work: Visual Structure
• Visual Affordances - Perceived and actual fundamental properties of object that determine how it could possibly used
• Appearance indicates how object should be used like

      chair for sitting

      table for placing things on

      knobs for turning

      buttons for pushing

      computers for ???

• Complex things may need explaining, but simple things should not
• When simple things need pictures, labels, instructions, then design has failed

• Transfer effects - people transfer their learning/ expectations of similar objects to current objects

      positive transfer: previous learning's also apply to new situation

      negative transfer: previous learning's conflict with new situation

1.5 Principles of HCI

Norman’s Seven Principles

1. Use both knowledge in world & knowledge in head
2. Simplify task structures.
3. Make things visible
4. Get the mapping right (User mental model = Conceptual model = Designed model)
5. Convert constrains into advantages (Physical constraints, Cultural constraints, Technological constraints)
6. Design for Error
7. When all else fails –Standardize

1.6 User Centered Design

      System is designed by considering user at it’s center position

      Process of designing tool from perspective of how it will be understood and used by human user

      Tool can be a website’s user interface or application’s user interface

      Goal of User-Centered design is to make products which have very high usability

      This includes how convenient the product is in terms of its usage, manageability, effectiveness.

Phrases used:

      Specify Context of Use - Identify primary users of product, why they will use the product, etc.

      Specify Requirements - Once context is specified, it is time to identify rough requirements of the product

      Create Design Solutions and Development - Based on product goals and requirements, start an iterative process of product design and development

      Evaluate Product - Product designers do usability testing to get users' feedback of product

References:

1. Alan Dix (2008). Human Computer Interaction. Pearson Education. ISBN 978-81-317-1703-5.
2. Gerard Jounghyun Kim (20 March 2015). Human–Computer Interaction: Fundamentals and Practice. CRC  Press. ISBN 978-1-4822-3390-2.
3. Ben Shneiderman; Catherine Plaisant; Maxine Cohen; Steven Jacobs (29 August 2013). Designing the User Interface: Strategies for Effective Human-Computer Interaction. Pearson Education Limited. ISBN 978-1-292-03701-1.
4. Donald A. Norman (2013). The Design of Everyday Things Basic Books. ISBN 978-0-465-07299-6.