Psychology of HCI (Card, Moran & Newell; 1983) Two information processors Human-Computer Interaction coupled in goal-directed action. perception output devices Session 3: information information The human user - Attention & Memory processing processing action input devices Human Computer MMI/SS09 1 MMI / SS09 2 Human Information Processor Input Sensors Filter Pattern Attention limits amount that need to be recognized & Recognition memorized Selection Short-Term Long-Term Memory Memory Response Abb. Reed, 2000 MMI / SS09 3 MMI / SS09 4 Standard model Atkinson & Shiffrin (1968) Input Human Information Sensors Processor - expanded Filter Sensory Memory Preprocessing (pattern recogn.) Perception Selection Cognitive Processing Interpretation Long-Term Memory Reasoning Short-Term Memory Experiences Deliberation Skills Standard theory of memory & information processing, Working Memory aka. modal model Response MMI / SS09 5 MMI / SS09 Sensory memory Sensory memory Sperling (1960) Modality-specific buffers for received stimuli (Neisser, 1967) Array of letters, presented for 50 milliseconds ! X! M! R! J Large capacities, but information lasts only short durations ! C! K! P! R ! V! F! L! B ! iconic memory: visual stimuli, ~250-400 msec ! echoic memory: aural stimuli, only little longer Whole-report method („recall as much as possible“) ! haptic memory: tactile stimuli, shorter ! 4.5 letters on average, letters "fade away" FIFO: memories are washed out or masked by new information Part-report method („recall specific elements“) ! iconic memory: By the time ~4 items have been extracted, the ! tone (high, medium, low) after presentation to cue subjects to remaining contents have been decayed report a particular row ! decay rate depends on intensity, contrast, duration of the ! Higher percentage of letters recalled, depending on delay of tone: stimulus, as well as the following of another stimulus (masking) 50ms: 9 (i.e. 3 per row) ! 300ms: 6 ! 1s: 4.5 ! Explanation: People attend to and scan the row image in sensory Example: Reading your watch quickly, twice memory, until it faded away MMI / SS09 7 MMI / SS09 8 Short-term memory (STM) STM limits - examples A more durable “scratch-pad” for temporary recall ! ~20-30s, if not maintained (see below) or externalized ! rapid and reliable access: ~ 70ms 21234827849 Very limited capacity 0121 414 2626 ! Miller (1956): 7 ± 2 chunks ! Cowan (2002): 4 ± 2 chunk Capacity limits can be overcome by chunking FB-IUS-AC-IAIB-M ! grouping of information into larger meaningful units ! found by looking for familiar pattern abstractions FBI-USA-CIA-IBM ! individual differences, e.g. chess masters vs. novices ! closure = successful formation and completion of chunks, also seen in everyday tasks that must be held in STM MMI / SS09 9 MMI / SS09 10 STM - maintenance STM - maintenance What happens if you need to keep information in memory What is the number? longer than 30 seconds? To demonstrate, memorize the following phone number (presented one digit at a time): 857-9163 8579163 The number lasted in your short-term memory longer than 30 seconds. Needs to be maintained through continued rehearsal. MMI / SS09 11 MMI / SS09 12 STM - maintenance rehearsal STM – maintenance rehearsal What happens if you can’t use maintenance rehearsal? What is the number? To demonstrate, memorize a phone number BUT count backwards from 1,000 by sevens (i.e., 1014, 1007, 1000 …) 628-5094 6285094 Without rehearsal, memory fades. MMI / SS09 13 MMI / SS09 14 Input Rehearsal STM & working memory Sensor repetition allows information to remain in working memory Working memory Filter longer than ~30 seconds ! place where basic cognitive operations are carried out (comprehension, decision-making, problem-solving,...) Limited in capacity, takes effort ! modality-dependent (e.g., rehearsal of language and sounds Preprocessing vs. inspection or rotation of mental images) (pattern recogn.) Sensory Memory Content of STM defines context of cognitive processing ! Can faciliate or hinder efficient processing Perception ! HCI: Beware of the context that is actively created by your Selection system‘s feedback and functions, in which the user operates Cognitive Processing Interpretation Long-Term Memory Reasoning Short-Term Memory Experiences Deliberation Skills WM = STM + „central executive“ Working Memory Response Rehearsal MMI / SS09 MMI / SS09 16 Working Memory Baddeley (2000) Brain regions involved in working memory Groome (2006), Fig. 6.10 MMI / SS09 17 MMI / SS09 18 Long-Term Memory Long-term memory (LTM) Repository for all our knowledge and experiences Once information passed from sensory to working ! slow access (~1/10 second), slow decay, huge capacity memory, it can be learned, i.e., encoded and stored in ! Storage for ... long-term memory " facts, data, concepts, ... " images, sounds, sents, ... " situation, episodes, processes, ... Maintenance Rehearsal " connections, conclusions, insights, ... " procedures, recipes, movements, ... Encoding Of big relevance for HCI Sensory Attention Sensory Working or Long-term ! combined knowledge about a system and the interaction - Memory Short-term memory the basis of a user‘s mental model of the system Input Memory ! distinguishes a novice from an expert user Retrieval MMI / SS09 19 MMI / SS09 20 LTM - different kinds Stanford Encycl. of Phil. L.R. Squire (UCSD) habit memory, procedural memory ! embodied skills such as typing, playing golf, using a knife and fork propositional memory, semantic memory ! network of conceptual information underlying our world knowledge recollective memory, episodic memory, personal memory ! experienced events and episodes, generic or specific, of more or less extended temporal periods declarative memory = semantic + episodic memory ! vs. non-declarative forms of memory Semantic Episodic ! more controversial: ‘explicit’ vs. ‘implicit’ memory systems " a matter of how a memory is accessed (by subject or labeled) MMI / SS09 21 MMI / SS09 22 Semantic vs. episodic memory Semantic memory (Tulving, 1983) Structure of semantic memory provides associative access Semantic Memory ! follows relationships between entities of information ! facts, concepts, meaning of words & things ! supports inference ! abstracted and generalized, not tied to place, time or event Semantic or associatve network (e.g., ACT-R) Episodic Memory ! closeness of concepts represented by closeness in graph ! serial, biographical ! inheritance – child nodes inherit properties of parent nodes ! tied to explicit autobiographical events ! relationships between bits of information explicit ! recall = subjective sense of “being there” ! supports inference through inheritance Learning of new information: embedding Distinction supported by neuropsychological evidence ! looking for associations with known facts or concepts ! Frontal lobe patients and some amnesics have relatively intact ! the more associations are found, the better something is semantic memory, but significantly impaired event memory learned, anchored in our conceptual knowledge MMI / SS09 23 MMI / SS09 24 Associative or semantic network ACT* (Anderson, 1993) Declarative vs. procedural memory Learning Retrieval Learning Executing Declarative memory Procedural memory Facts, dates, concepts, Skills, habits, ... models,events, ... LTM Automatic sequences of keystrokes, menue selections, condition-action rules, etc. MMI / SS09 25 MMI / SS09 26 Summary - memories How is information memorized? Rehearsal ! information moves from STM to LTM through repetition ! „total time“ hypothesis: amount of information ~ rehearsal time Distribution of practice ! optimized by spreading learning over time Importance of structure, meaning, and familiarity ! information about objects is easier to remember " Faith Age Cold Tenet Quiet Logic idea Value Past Large " Boat Tree Cat Child Rug Plate Church Gun Flame Head ! information related to existing structures is more easily incorporated into memory (~embedding) MMI / SS09 27 MMI / SS09 28 How is information forgotten ? How is information retrieved? Decay ! information is lost gradually, but very slowly Memory retrieval in HCI: recall Interference ! information must be retrieved ! new information replaces old: retroactive interference from memory, without any hint (free recall) " new tel. number masks old one ! can be assisted by cues, e.g. categories, imagery (cued recall) ! old may interfere with new: proactive inhibition " find yourself driving to your old house recognition ! present information „evokes“ that it has been seen before, plus Note: memory is selective, affected by emotion – further useful knowledge can subconsciously `choose' to forget ! less complex than recall - information itself acts as a cue ! frequent design goal MMI / SS09 29 MMI / SS09 30 Free recall (Glanzer & Cunitz, 1966) Retrieval is of unequal difficulty • Free recall Example: learning a word list and free recall (“Who are these ! More likely to remember words at the beginning (Primacy persons?“) effect) and end of the list (Recency effect) • Cued recall Evidence for LTM-STM (“Last name ! Recency effects reflect starts with an limited STM capacity, M.“) ceases with time ! Primacy effects reflect transfer to LTM via • Recognition rehearsal (“Whose last ! Primacy effect more name is robust than recency, less Fischer?“) affected by interference or delay H. Markowitsch, 2006 MMI / SS09 31 MMI / SS09 32 Expert vs. novice users Human Information Processor Input Beginners: memorize and operate upon simple facts and rules (declarative), must build up