Week 6 -8- the Computer.pdf

Chp 2-4: HCI Concepts: Human, Computer, Interaction SE234: Human Computer Interaction ©PRISCILLA OLAWALE (MSC) Spring 2024 The Computer a computer system is made up of various elements each of these elements affects the interaction ◦ input devices – text entry and pointing...

Chp 2-4: HCI Concepts: Human, Computer, Interaction SE234: Human Computer Interaction ©PRISCILLA OLAWALE (MSC) Spring 2024 The Computer a computer system is made up of various elements each of these elements affects the interaction ◦ input devices – text entry and pointing ◦ output devices – screen (small&large), digital paper ◦ virtual reality – special interaction and display devices ◦ physical interaction – e.g. sound, haptic, bio-sensing ◦ paper – as output (print) and input (scan) ◦ memory – RAM & permanent media, capacity & access ◦ processing – speed of processing, networks 2 ©Priscilla Olawale (MSc) SPRING2024 Interacting with computers to understand human–computer interaction … need to understand computers! what goes in and out devices, paper, sensors, etc. what can it do? memory, processing, networks 3 ©Priscilla Olawale (MSc) SPRING2024 A ‘typical’ computer system oscreen, or monitor, on which there are windows okeyboard omouse/trackpad variations ◦ desktop ◦ laptop ◦ PDA the devices dictate the styles of interaction that the system supports If we use different devices, then the interface will support a different style of interaction 4 ©Priscilla Olawale (MSc) SPRING2024 How many … computers in your house? ◦ hands up, … … none, 1, 2 , 3, more!! computers in your pockets? are you thinking … … PC, laptop, PDA ?? 5 ©Priscilla Olawale (MSc) SPRING2024 How many computers … in your pockets? in your house? ◦ PDA ◦ PC ◦ phone, camera ◦ TV, VCR, DVD, HiFi, ◦ smart card, card with magnetic cable/satellite TV strip? ◦ microwave, cooker, washing ◦ electronic car key machine ◦ USB memory ◦ central heating ◦ security system try your pockets and bags can you think of more? ©Priscilla Olawale (MSc) SPRING2024 6 Interactivity? Long ago in a galaxy far away … batch processing ◦ punched card stacks or large data files prepared ◦ long wait …. ◦ line printer output … and if it is not right … Now most computing is interactive ◦ rapid feedback ◦ the user in control (most of the time) ◦ doing rather than thinking … Is faster always better? 7 ©Priscilla Olawale (MSc) SPRING2024 Richer interaction sensors and devices everywhere 8 ©Priscilla Olawale (MSc) SPRING2023 TEXT ENTRY DEVICES  keyboards (QWERTY et al.)  chord keyboards, phone pads  handwriting, speech 9 ©Priscilla Olawale (MSc) SPRING2024 Keyboards Most common text input device Allows rapid entry of text by experienced users Keypress closes connection, causing a character code to be sent Usually connected by cable, but can be wireless 10 ©Priscilla Olawale (MSc) SPRING2024 layout – QWERTY Standardised layout but … ◦ non-alphanumeric keys are placed differently ◦ accented symbols needed for different scripts ◦ minor differences between UK and USA keyboards QWERTY arrangement not optimal for typing – layout to prevent typewriters jamming! Alternative designs allow faster typing but large social base of QWERTY typists produces reluctance to change. 11 ©Priscilla Olawale (MSc) SPRING2024 QWERTY (ctd) 12 ©Priscilla Olawale (MSc) SPRING2024 alternative keyboard layouts Alphabetic ◦ keys arranged in alphabetic order ◦ not faster for trained typists ◦ not faster for beginners either! Dvorak ◦ common letters under dominant fingers ◦ biased towards right hand ◦ common combinations of letters alternate between hands ◦ 10-15% improvement in speed and reduction in fatigue ◦ But - large social base of QWERTY typists produce market pressures not to change 13 ©Priscilla Olawale (MSc) SPRING2024 special keyboards designs to reduce fatigue for RSI for one handed use e.g. the Maltron left-handed keyboard 14 ©Priscilla Olawale (MSc) SPRING2024  Chord keyboards only a few keys - four or 5 letters typed as combination of keypresses compact size – ideal for portable applications short learning time – keypresses reflect letter shape fast – once you have trained BUT - social resistance, plus fatigue after extended use NEW – niche market for some wearables 15 ©Priscilla Olawale (MSc) SPRING2024 phone pad and T9 entry use numeric keys with multiple presses 2–abc 6-mno 3-def 7-pqrs 4-ghi 8-tuv 5-jkl 9-wxyz hello = 4433555[pause]555666 surprisingly fast! T9 predictive entry ◦ type as if single key for each letter ◦ use dictionary to ‘guess’ the right word ◦ hello = 43556 … ◦ but 26 -> menu ‘am’ or ‘an’ 16 ©Priscilla Olawale (MSc) SPRING2024 Handwriting recognition Text can be input into the computer, using a pen and a digesting tablet ◦ natural interaction Technical problems: ◦ capturing all useful information - stroke path, pressure, etc. in a natural manner ◦ segmenting joined up writing into individual letters ◦ interpreting individual letters ◦ coping with different styles of handwriting Used in PDAs, and tablet computers … … leave the keyboard on the desk! 17 ©Priscilla Olawale (MSc) SPRING2024 Speech recognition Improving rapidly Most successful when: ◦ single user – initial training and learns peculiarities ◦ limited vocabulary systems Problems with ◦ external noise interfering ◦ imprecision of pronunciation ◦ large vocabularies ◦ different speakers 18 ©Priscilla Olawale (MSc) SPRING2024 Numeric keypads for entering numbers quickly: ◦ calculator, PC keyboard for telephones 1 2 3 7 8 9 not the same!! 4 5 6 4 5 6 ATM like phone 7 8 9 1 2 3 0 # 0. = * telephone calculator 19 ©Priscilla Olawale (MSc) SPRING2024