HCI - Quick Revision - 5 - 11 PDF

# Chapter 1: Introduction to Human Computer Interaction ## Define what is Human Computer Interaction Human-computer interaction (HCI) is the study, planning, and design of the interaction between people (users) and computers. ## Identify the fundamental components of HCI: human user, computer sys...

# Chapter 1: Introduction to Human Computer Interaction ## Define what is Human Computer Interaction Human-computer interaction (HCI) is the study, planning, and design of the interaction between people (users) and computers. ## Identify the fundamental components of HCI: human user, computer system, and nature of interactive process. | Fundamentals components of an interactive system | |:----------------------------------------------------------------------------------------------| | Input Output | | Memory | | Process & Applied | | Emotion | | Individual differences | | HUMAN USER | | HCI | | Input | | Output | | Virtual Reality | | Physical Interaction | | COMPUTER SYSTEM | | Paper | | Memory | | Processing | | Interaction Models | | Ergonomics | | Interaction Styles | | Context | ## Describe the importance of user interface design. The ONLY contact medium that the user has with the system. The interface is the system designer's way of representing the system to the user; known as a conceptual model. If the system has the confused interface, the user may choose not to use the system at all OR will use it incorrectly. A well-designed interface can increase productivity. ## Explain how computer technology influences the nature of interaction and style of the interface. **a. Input/output devices for interactive users** * keyboards (QWERTY etc.) * chord keyboards, phone pads * handwriting, speech **b. Virtual reality systems and 3D visualization** * positioning in 3D space * moving and grasping * seeing 3D (helmets and caves) **c. Physical devices: sound, smell, sensors** * Sound * beeps, bongs, clonks, whistles, and whirrs used for error indication, confirmation of actions e.g., keyclick **d. Environment and bio-sensing** * sensors all around us * car courtesy light — small switch on door * ultrasound detectors — security, washbasins * RFID security tags in shops * temperature, weight, location * and even our own bodies * iris scanners, body temperature, heart rate, galvanic skin response, blink rate **e. Memory capacity** * short term and long term * on silicon chips * 100 nano-second access time * usually volatile (lose information if power turned off) * data transferred at around 100 Mbytes/sec * Some non-volatile RAM used to store basic set-up information * Typical desktop computers: 64 to 256 Mbytes RAM **f. Processing speed** * what do the numbers mean? * some sizes (all uncompressed) * this book, text only ~ 320,000 words, 2Mb the Bible ~ 4.5 Mbytes * scanned page ~ 128 Mbytes * (11x8 inches, 1200 dpi, 8bit greyscale) * digital photo ~ 10 Mbytes * (2-4 mega pixels, 24 bit colour) * video ~ 10 Mbytes per second * (512x512, 12 bit colour, 25 frames per sec ## Describe the various interface styles **a. Command line interface** * operating systems – DOS/UNIX * short instructions for efficiency/repetition * √3 good for experts * ×7 poor for novices **b. Menus** * a set of options * no need to remember, only recognize) options must be self-explanatory * they can take up space so we have * pull-down/pop-up/pin-up/cascading/pie * features – hierarchical, short-cut, icons, dividers, disabled/invisible entries, menu items that display a dialog. **c. Natural language** * An attractive option: familiar speech recognition or typed natural language. * speech recognition or typed natural language; problems: * Speech – accent, inflection * typing – slow, spelling * poor for experts, vague, ambiguous **d. WIMP interface: Windows, icon, menus and pointers** **Icon** * Icons embody the idea that different people have different cognitive styles. * Some users prefer text-oriented views, and some prefer graphics. * An icon is an image, picture, or symbol representing a concept. * Can take many forms: * Realistic * Highly stylized * Arbitrary symbol (difficult for the user to interpret) **e. Question/answer and query dialog** * A simple mechanism for providing input to an application in a specific domain. * input is constrained – ATM, “wizard" dialogue * good for novices but restricted functionality * next question/action depends on last answer **f. Form-fills and spreadsheet** * Primarily for data entry but can also be useful in data retrieval applications * hard-copy metaphor * used for data entry & specifying a data retrieval operation * good for novices as it is familiar (similar to paper form) * need to allow editing of errors * need to allow easy movement between fields **g. Point-and-click interfaces** * Closely related to the WIMP style * More closely tied to ideas of hypertext * not tied to mouse-based interfaces – extensively used in touchscreen information systems. * Popularized by world wide web pages. * Incorporate all the above types of point and click navigation: * Highlighted words * Maps * Iconic buttons **h. 3D interfaces** * human-computer interaction in which the user's tasks are performed directly in a 3D spatial context. * VR is only part of a range of 3D techniques available to the interface designer. * Simple technique for WIMP elements, buttons, scroll bars, etc., are given a 3D appearance using shading. * Complex technique uses interfaces with a 3D workspace. * Object in perspective when at an angle to the viewer, and shrink when they 'further away'. **i. Web navigation** * Readers need a sense of context of their place within an organization of information. * In paper documents, this sense of where you are is a mixture of graphic and editorial organizational cues supplied by the graphic design of the book, the organization of the text, and the physical sensation of the book as an object. * Electronic documents provide none of the physical cues we take for granted in assessing information. * When we see a web hypertext link on a page, we have few clues to where we will be led, how much information is at the other end of the link, and exactly how the linked information relates to the current page. ## Explain the role of ergonomics in interface design. * Ergonomics is the study of the physical characteristics of interaction: * the design of controls (icons, physical input devices) * the physical environment where the interaction is situated * layout & physical qualities of the display (e.g. screen) * This is a huge and established field; consider some aspects: * arrangement of controls * physical environment * health issues * use of colour ## Describe Models of interaction: **a. Norman's execution-evaluation cycle** 1. The Establishing the goal 2. Forming the intention (planning: - objectives, scopes). 3. Specifying the actions sequence (specific action sequence planning) 4. Executing the action (perform the action sequence) 5. Perceiving the system state (observe) 6. Interpreting the system state (the feedback) 7. Evaluating the system state with respect to goal (conclusion) e.g., seven stages of Norman's model **b. The interaction framework** * There are 4 steps in the interaction cycle * The user formulates a goal and task to achieve it. This is expressed in the input language. * Input languages is translated into core language * System transforms itself into a new state * The state of the system is then rendered in the output language and sent to the user.