Dr. Javier Gonzalez-Sanchez javiergs@calpoly.edu www.javiergs.info o ffi ce: 14 -227 CSC 486 Human-Computer Interaction Lecture 10. Cognitive Factors

Previously …

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Cognitive Factors

De f inition • A cognitive f a ctor is s ment a l a bility th a t in f luences how individu a ls process, a n a lyze, use inform a tion to inter a ct with their environment. • Underst a nding perception (interpret), a ttention (focus), memory, cognitive lo a d (e ff ort), a nd problem-solving (use) helps designers cre a te intuitive, user-friendly systems. • Systems should be us a ble for everyone, including those with visu a l, a uditory, motor, or cognitive imp a irments. 7

Memory

De f inition How users ret a in a nd rec a ll inform a tion while inter a cting with a system • Short-term memory (Working Memory): Tempor a ry stor a ge of inform a tion, such a s remembering a menu p a th or a recently entered p a ssword. • Long-term memory: Retention of le a rned inform a tion, like interf a ce l a youts a nd frequently used comm a nds. Interf a ces should minimize reli a nce on memory. E.g. by using cle a r n a vig a tion, tooltips, a nd recogniz a ble icons. 9

Working Memory Test A. Digit Sp a n Test. • Evaluates working memory a nd a ttention. • E.g. remembering n a vig a tion steps. B. Letter-Number Sequencing • Evaluates working memory, a ttention, a nd cognitive lo a d • E.g. process multit a sking in a pplic a tions. C. Corsi Block-T a pping Test • Ev a lu a tes memory, sp a ti a l a ttention, a nd cognitive lo a d. • E.g. Ability to ret a in a nd rec a ll sp a ti a l sequences in VR a nd AR interf a ces. 10

★ Digit Span Test The test is usu a lly divided into two p a rts: 1. Digit Sp a n Forw a rd • The p a rticip a nt he a rs or sees a sequence of numbers (e.g., 4 - 7 - 2). • They must rec a ll a nd repe a t the sequence ex a ctly a s presented. • The length gr a du a lly incre a ses until the p a rticip a nt c a n no longer correctly rec a ll it. 2. Digit Sp a n B a ckw a rd • The p a rticip a nt is given a sequence of numbers but must rec a ll them in reverse order • The sequences incre a se in di ff iculty over time. The a ver a ge a dult c a n typic a lly rec a ll 5–7 digits forw a rd a nd a round 4–5 digits b a ckw a rd. 11

• The p a rticip a nt is presented with a sequence cont a ining both letters a nd numbers in r a ndom order (e.g., B - 4 - A - 2). • They must ment a lly reorder the sequence, f irst a rr a nging numbers in a scending order, followed by letters in a lph a betic a l order (e.g., 2 - 4 - A - B). • The test begins with short sequences a nd gr a du a lly incre a ses in length until the p a rticip a nt c a n no longer a ccur a tely rec a ll a nd re a rr a nge the items. Higher scores indic a te strong working memory, a ttention, a nd cognitive f lexibility. Letter-Number Sequencing 12

• The test consists of nine identic a l blocks pl a ced in r a ndom positions on a bo a rd or screen. • Computer t a ps a sequence of blocks in a speci f ic order. • The p a rticip a nt must w a tch a nd then reproduce the sequence by t a pping the s a me blocks in the s a me order. • The sequences st a rt short (e.g., 2 t a ps) a nd gr a du a lly incre a se in length. • The score is b a sed on the longest sequence the p a rticip a nt c a n successfully rec a ll before m a king mist a kes. Aver a ge a dult rec a ll: 5–7 blocks in sequence. ★ Corsi Block-Tapping Test 13

Attention and Perception

Attention Attention determines how users focus on t a sks a nd f ilter out distr a ctions. It includes: • Selective a ttention: Focusing on relev a nt inform a tion while ignoring b a ckground noise (e.g., distinguishing key a lerts in a cluttered d a shbo a rd). • Divided a ttention: M a n a ging multiple t a sks simult a neously (e.g., using multiple a pps on a split-screen). • Sust a ined a ttention: M a int a ining focus over a long period (e.g., re a ding a long document). Well-designed interf a ces should guide a ttention. 15

Perception Perception refers to how users interpret a nd m a ke sense of sensory input (e.g., visu a ls, sounds, touch). It includes: • Visu a l perception: Recognizing UI elements, text legibility, a nd color contr a st. • Auditory perception: Underst a nding noti f ic a tions a nd voice comm a nds. • H a ptic perception: Inter a cting through touch feedb a ck (e.g., vibr a tion responses). UI elements a re perceptible, e a sy to distinguish, a nd do not overwhelm users with excessive stimuli. 16

Attention Tests A. Stroop Test • a person’s a bility to ignore irrelevant information while focusing on a speci f ic t a sk,selective a ttention, cognitive f lexibility, a nd processing speed.Measuring attention- switching in multitasking interfaces B. Tr a il M a king Test • Ev a lu a ting t a sk-switching in UI/UX work f lows. processing speed, a ttention, memory C. Symbol Digit Mod a lities Test (SDMT) • Processing speed for d a t a -he a vy a pplic a tions. processing speed, a ttention, working memory, a nd cognitive f lexibility 17

★ Stroop Test • Presents p a rticip a nts with color words (e.g., “RED”, “BLUE”) written in incongruent ink colors. The p a rticip a nt’s t a sk is to click on a colored button corresponding to the ink color., not the word itself. • Congruent Condition: When the word a nd ink color m a tch (e.g., “RED” written in red ink). • Incongruent Condition: When the word a nd ink color do not m a tch (e.g., “RED” written in blue ink). • Since re a ding words is more a utom a tic th a n n a ming colors, p a rticip a nts experience a del a y (Stroop E ff ect) in the incongruent condition. • Scoring in a Digit a l Stroop Test: Re a ction Time (RT): F a ster a nd Accur a te responses indic a te better cognitive control. 18

★ Trail Making Test (TMT) TMT consists of two p a rts, TMT-A a nd TMT-B, which test di ff erent cognitive a bilities • A -Measures: Visu a l se a rch a bility, a nd motor coordin a tion. • B- Cognitive Flexibility & T a sk Switching Circles a re sc a ttered a cross the screen without following a strict grid to ensure th a t users a ctively se a rch for the next element in the sequence. • MT-A (Processing Speed & Visu a l Sc a nning) • • T a sk: The p a rticip a nt must connect numbered circles (1→2→3…) in sequenti a l order a s quickly a s possible. • TMT-B (Cognitive Flexibility & T a sk Switching) • • T a sk: The p a rticip a nt a ltern a tes between numbers a nd letters in sequence (1→A→2→B→3→C…). 19

★ Symbol Digit Modalities Test • The SDMT requires p a rticip a nts to m a tch symbols to corresponding digits using a key provided a t the top of the test. • Test Structure: • 1. A key (legend) is provided th a t p a irs symbols with numbers (1–9). • 2. Below the key, a series of symbols is presented without their corresponding numbers. • 3. The p a rticip a nt must quickly f ill in the correct numbers for a s m a ny symbols a s possible within 90 seconds • KEY: ‗ → 1 ˛ → 2 ■ → 3 ◆ → 4 ● → 5 ⬤ → 6 ✚ → 7 — → 8 ✿ → 9 • TASK ‗ __ ■ __ ˛ __ ● __ ✿ __ • RESPONES ‗ 1 ■ 3 ˛ 2 ● 5 ✿ 9 • Score = Tot a l number of correct symbol-digit m a tches in 90 seconds. • • Higher scores indic a te f a ster cognitive processing a nd better a ttention control. 20

Problem Solving And Decision Making

Problem Solving Problem-solving in HCI involves users f inding solutions within a n interf a ce, such a s troubleshooting errors, n a vig a ting complex softw a re, or completing t a sks with minim a l instruction. Interf a ces should support intuitive design, o ff er guid a nce, a nd provide cle a r feedb a ck when users encounter obst a cles. 22

Decision-Making Decision-m a king refers to how users choose between multiple options b a sed on a v a il a ble inform a tion, preferences, a nd p a st experiences. Ex a mple in HCI: Selecting a product in a n e-commerce site, choosing priv a cy settings, or responding to system a lerts. Interf a ces should provide cle a r, concise inform a tion to a id decision-m a king, minimize decision f a tigue, a nd prevent user errors with undo options a nd con f irm a tions. 23

Executive Function, Flexibility & Capacity Tests • Wisconsin C a rd Sorting Test (WCST) – How users a d a pt to ch a nging UI elements. problem-solving • Tower of London/H a noi Test – Underst a nding pl a nning beh a viors in t a sk execution • R a ven’s Progressive M a trices – Me a suring problem-solving in a d a ptive UIs. Problem Solving. • C a ttell Culture F a ir Intelligence Test (CFIT) – Non-verb a l intelligence for diverse user groups. Problem Solving. 24

★ Wisconsin Card Sorting Test • Users sort virtu a l c a rds by color, sh a pe, or number, but the rule ch a nges unpredict a bly. • Re a l-time feedb a ck guides users with “Correct” or “Incorrect” mess a ges. • Timers a nd scoring systems tr a ck response speed a nd a ccur a cy. • [ Sorting Are a ] → Four reference c a rds (color, sh a pe, number v a ri a tions) • [ Deck of C a rds ] → Users dr a g & drop c a rds onto correct c a tegory • [ Feedb a ck P a nel ] → AI shows "Correct" or "Incorrect" + a djusts di ff iculty 25

★ Tower of London • The t a sk consists of three vertic a l pegs of di ff erent heights a nd three colored b a lls (red, green, a nd blue). • The b a lls c a n be moved one a t a time, with the go a l of re a ching a prede f ined t a rget a rr a ngement. • The p a rticip a nt must complete the t a sk in the fewest number of moves possible. 26

Questions 27

Lab

29 Can you implement one or two of these test in Java (Embedded with your Subscriber)

Questions 30

CSC 486 Human-Computer Interaction Javier Gonzalez-Sanchez, Ph.D. javiergs@calpoly.edu Winter 2025 Copyright. These slides can only be used as study material for the class CSC 486 at Cal Poly. They cannot be distributed or used for another purpose.