FIT3063 HUMAN COMPUTER INTERACTION

Transcription

1 FIT3063 HUMAN COMPUTER INTERACTION Exam Date: 20/06/2017 Week 1 - INTRODUCTION TO HCI Three aspects of HCI: How do we design it? By considering design approaches. Eg: graphical design basics, requirements gathering, task analysis. How do we build it? Need to consider implementation techniques and tools. Eg: prototyping techniques, development tools. How do we evaluate it? Need to consider evaluation techniques. Eg: productivity, usability testing, formative and summative evaluation. Human interaction with a computer happens via a interface. A good interface: Enables the required task to be performed. Minimises the resources and effort required. Encourages easy, natural and engaging interaction. 1

2 Challenges faced by designers: Variety of techniques and devices for human-computer communication e.g. visual displays range in size from small handheld devices to large walls. Information may be delivered over different media. Information may need to be translated into other languages. Systems may be used by single or multiple users. Systems may be used in different contexts. May need to cater for a variety of users universal usability. Three basic principles of HCI: People want ease of use usually provided by simplicity and transfer of existing experience. The user view is different to the system engineer's view. Often engineers design systems to perform a set of functions rather than with the user in mind. Computers and people are both better at some tasks than others however they are better at different tasks. Computers are better at repetitive simple operations: counting, comparing & sorting. Humans are better at problem solving, reasoning, pattern recognition, sensing unusual events. Human senses and abilities: Vision : e.g. depth, contrast, colour blindness, peripheral vision and motion sensitivity. Hearing: e.g. audio cues must be distinct. Touch: e.g. keyboard and touchscreen sensitivity and motor abilities. Motor control / hand-eye coordination: e.g. use of pointing devices. Physical strength: e.g. power steering, powered train doors. 2

3 Users with disability: Need to plan early to accommodate users with disabilities as costs may be very high later. Some countries have laws which specify requirements to comply with equal opportunity legislation. User Interface Evaluation Evaluation of a user interface depends largely on human factors criteria: Learning time Performance speed Error rates of users Retention over time Subjective satisfaction Week 2 - EVOLUTION OF THE INTERFACE: METAPHORS AND ICONS History of GUI Early use of cathode ray tube (CRT) monitors and pen devices led to development of the field of computer graphics. Important building blocks for GUI included the mouse, bitmapped displays, personal computers, windows, the desktop metaphor, and point-and-click editors. Tools to support activities: how people understand their tasks (mental models) how people represent their tasks (metaphors) how people describe their tasks (language/icons) 3

4 Mental Models 1. People have mental models of how things work, based on existing knowledge and experience. 2. A good mental model allows the user to correctly predict the effects of their action. A conceptual model is a high-level description of how a system is organised and operates. It specifies and describes: The main metaphors and analogies used in the design. The concepts shown to the users including task- domain objects and attributes. The relationships between these concepts. The mapping between these concepts. Metaphor : the use of familiar symbols, terms, objects and associations to represent a new concept. E.g. Desktop. Metaphors help users think about screen objects as they would about real-world objects. A metaphor can be based on activity, object or a combination of both. The can be: Verbal Textual Graphical A feeling of presence Benefits: - Learning by analogy is one of the most basic approaches to learning. - Takes advantage of prior knowledge of the world. - Makes learning new systems easier as it helps users understand complex concepts by providing shortcuts. 4

5 Problems: - Mixing metaphors or extending a metaphor too far can cause confusion - may break conventional or cultural rules. E.g. Start to Shut Down - Can limit a designer s ability to imagine new possibilities. - Forces users to only understand the system in terms of the metaphor. - Designers can inadvertently use bad existing designs and transfer the bad parts over. Bad Metaphor: Search Icon. (Confusing, as used for different things) Good Metaphor: Dropbox. (Drop all files into one box ) Icons are pictorial images used to represent features and commands. They can help reduce the complexity of the system. Three main types of representation: Based on a metaphor Direct mapping Convention Icons may not transfer well across different cultures. It is much easier to represent objects than actions. Difference between a metaphor and an icon: - A metaphor describes a concept. - An icon represents an action or an object. _ 5

6 Icons Design - Selected states must be obvious, and the number of states limited. - Icons should be scalable. - Use conventions where possible. Animated icons can convey additional information. Considerations: Understandable Familiar Unambiguous Memorable Scalable Distinct Informative Attractive Legible Compact Coherent Week 3 - THEORIES AND MODELS Models abstract the theories. Principles apply the theories. Standards, Guidelines, and Style Guides are narrowly focused, evolved from theories / models / experience. 6