Information Input and Information Input and ProcessingProcessing

Chap 3Chap 3

Information Input and ProcessingInformation Input and Processing

Information TheoryInformation Theory Displaying InformationDisplaying Information Coding of InformationCoding of Information CompatibilityCompatibility A Model of Information A Model of Information

Processing Processing Fig 3-2Fig 3-2

PerceptionPerception MemoryMemory

Decision MakingDecision Making AttentionAttention Age and Information ProcAge and Information Proc

essing essing Mental Workload Mental Workload Human Factors in the InfHuman Factors in the Inf

ormation Revolution ormation Revolution

Displaying InformationDisplaying Information

Direct vs. Indirect SensingDirect vs. Indirect Sensing

Stimuli for Indirect Sensing: DisplayStimuli for Indirect Sensing: Display• Coded stimuliCoded stimuli• Reproduced stimuliReproduced stimuli

Types of Information Presented by DisplaysTypes of Information Presented by Displays Selection of Display ModalitySelection of Display Modality

(cont.)(cont.)

Displaying InformationDisplaying Information Types of Information Presented by DisplaysTypes of Information Presented by Displays

• Quantitative InformationQuantitative Information

• Qualitative InformationQualitative Information• Status Information: Status Information: (ex) on/off, TV channels(ex) on/off, TV channels

• Warning and Signal InformationWarning and Signal Information• Representational Information: Representational Information: pictorial, graphicpictorial, graphic

• Identification Information: Identification Information: (ex) traffic lane, color-coded pipes(ex) traffic lane, color-coded pipes

• Alphanumeric and Symbolic InformationAlphanumeric and Symbolic Information

• Time-phased Information:Time-phased Information: (ex) Morse code, blinker lights (ex) Morse code, blinker lights

(cont.)(cont.)

Displaying InformationDisplaying Information

Selection of Display ModalitySelection of Display Modality• Visual vs. AuditoryVisual vs. Auditory

Tab 3-1Tab 3-1

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Coding of InformationCoding of Information CodingCoding: : original stimulus information original stimulus information converted to a new form converted to a new form and display symbolicallyand display symbolically 分類分類 : :

• Stimulus dimension: single vs. multipleStimulus dimension: single vs. multiple• Utility: identify vs. distinguishUtility: identify vs. distinguish

Absolute vs. Relative JudgmentsAbsolute vs. Relative Judgments• Absolute: identify, comparison in memoryAbsolute: identify, comparison in memory• Relative: distinguish (same or different)Relative: distinguish (same or different)

(cont.)(cont.)

Coding of InformationCoding of Information

Making Absolute Judgments along Single DimeMaking Absolute Judgments along Single Dimensionsnsions: : Tab 3-2Tab 3-2 • Fewer discrimination than relativeFewer discrimination than relative• 7 7 ±± 2 (limitation of human memory)2 (limitation of human memory)

Making Absolute Judgments along Multiple DiMaking Absolute Judgments along Multiple Dimensionsmensions• Orthogonal: independent,Orthogonal: independent, ＜ ＜ product of singleproduct of single • Redundant: not independent,Redundant: not independent, ＜ ＜ orthogonalorthogonal

(cont.)(cont.)

Coding of InformationCoding of Information

Characteristics of a Good Coding SystemCharacteristics of a Good Coding System• Detectability of CodesDetectability of Codes

• Discriminability of CodesDiscriminability of Codes

• Meaningfulness of CodesMeaningfulness of Codes

• Standardization of CodesStandardization of Codes

• Use of Multidimensional CodesUse of Multidimensional Codes

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CompatibilityCompatibility Compatibility:Compatibility: relationship of stimuli and responses relationship of stimuli and responses to human expectationto human expectation

Types of CompatibilityTypes of Compatibility• Conceptual CompatibilityConceptual Compatibility

Meaningfulness of Codes & symbols: Meaningfulness of Codes & symbols: (ex) airport: aircraft symbol vs. green square(ex) airport: aircraft symbol vs. green square

Meaningful Abbreviations: (ex) commands (computer)Meaningful Abbreviations: (ex) commands (computer)• Movement CompatibilityMovement Compatibility• Spatial CompatibilitySpatial Compatibility• Modality Compatibility Modality Compatibility (cont.) (cont.)

CompatibilityCompatibility

Types of CompatibilityTypes of Compatibility• Modality Compatibility Modality Compatibility Fig 3-1Fig 3-1

Input:Input: A Auditory (speech)uditory (speech)

VVisual (display on screen)isual (display on screen) Output: Output: SSpoken responsepoken response

MManual responseanual response Task: Verbal: A/STask: Verbal: A/S

Spatial: V/MSpatial: V/M

(cont.)(cont.)

CompatibilityCompatibility Origins of Compatibility RelationshipsOrigins of Compatibility Relationships

• Intrinsic in the situation (e.g. isomorphic)Intrinsic in the situation (e.g. isomorphic)• Culturally acquiredCulturally acquired

Identification of Compatibility RelationshipsIdentification of Compatibility Relationships• Obvious (e.g. spatial), but check out the generalityObvious (e.g. spatial), but check out the generality• Empirical exp.Empirical exp.

DiscussionDiscussion• Empirically, not self-evidentEmpirically, not self-evident• Not universalNot universal• Trade-offTrade-off

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AttentionAttention

Selective AttentionSelective Attention Focus AttentionFocus Attention Divided AttentionDivided Attention Sustained AttentionSustained Attention

(cont.)(cont.)

AttentionAttention Selective AttentionSelective Attention

• Load stress vs. Speed stressLoad stress vs. Speed stress• Guideline: p.71Guideline: p.71

Few channelsFew channels Provide information: relative importanceProvide information: relative importance Reduce the overall level of stressReduce the overall level of stress Preview informationPreview information Training: optimal scan patternsTraining: optimal scan patterns Close togetherClose together Auditory: do not mask one anotherAuditory: do not mask one another Stimuli separated temporally, self-pacedStimuli separated temporally, self-paced

(cont.)(cont.)

AttentionAttention

Focus AttentionFocus Attention• Proximity of the sources: Proximity of the sources: • Distinct: Distinct: • Guidelines: attended channel vs. competing channels Guidelines: attended channel vs. competing channels

(p.72)(p.72) DistinctDistinct Separate (in physical space)Separate (in physical space) Reduce of no. of competing channelsReduce of no. of competing channels Salient: larger, brighter, louder, centrally locatedSalient: larger, brighter, louder, centrally located

(cont.)(cont.)

AttentionAttention

Divided Attention: Divided Attention: time-sharingtime-sharing

• Single-Resource TheoriesSingle-Resource Theories

• Multiple-Resource TheoriesMultiple-Resource Theories (Wickens, 1984)(Wickens, 1984) Stages: Perceptual and central processing Stages: Perceptual and central processing vs. Response selection and executionvs. Response selection and execution Input modalities: Auditory vs. VisualInput modalities: Auditory vs. Visual Processing codes: Spatial vs. VerbalProcessing codes: Spatial vs. Verbal Responses: Vocal vs. Manual responseResponses: Vocal vs. Manual response

–– –– driving a car while talking on the telephonedriving a car while talking on the telephone

(cont.)(cont.)

AttentionAttention Divided Attention: Divided Attention: time-sharingtime-sharing

• Guideline:Guideline: p.74p.74 Dissimilar: stages, input modalities, . . .Dissimilar: stages, input modalities, . . . Number of potential sources of information↓Number of potential sources of information↓ Relative prioritiesRelative priorities Difficulty level ↓Difficulty level ↓ Learning of the manual task↑(automatic)Learning of the manual task↑(automatic)

–– –– 儘可能降低難度儘可能降低難度(cont.)(cont.)

AttentionAttention Sustained AttentionSustained Attention

• Vigilance decrementVigilance decrement

20-35 min (lab), Exponential 20-35 min (lab), Exponential Fig 3-4Fig 3-4

• GuidelineGuideline: p.75-76: p.75-76 降低疲勞降低疲勞 work-rest schedules, task variationwork-rest schedules, task variation

environmental factors: optimalenvironmental factors: optimal

(cont.)(cont.)

AttentionAttention Sustained AttentionSustained Attention

• GuidelineGuideline: p.75-76: p.75-76 Detect signal Detect signal 難度下降難度下降 conspicuity of the signal↑(conspicuity of the signal↑( 明顯）明顯） uncertainty: where & what↓uncertainty: where & what↓

training: make clear the nature of the signaltraining: make clear the nature of the signal

　　呈現 　　呈現 signalsignal 之速率↓之速率↓ 提高 提高 motivationmotivation

　　強調工作的重要性　　強調工作的重要性　　給予 　　給予 artificial signal, artificial signal, 並給予回饋並給予回饋

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Age and Information ProcessingAge and Information Processing

Changes in Information Processing CapacityChanges in Information Processing Capacity• Slowing Slowing performance:performance: central-cognitive, perceptual-motorcentral-cognitive, perceptual-motor

• Working memory↓(shift of attention)Working memory↓(shift of attention)

• LTM (transferring)↓LTM (transferring)↓

• Difficulty: incompatibility, ambiguous stimuliDifficulty: incompatibility, ambiguous stimuli

(cont.)(cont.)

Age and Information ProcessingAge and Information Processing Guideline:Guideline:

• Strengthen signalsStrengthen signals

• Reduce irrelevant detailsReduce irrelevant details

• Compatibility↑Compatibility↑

• Time-sharing demand↓Time-sharing demand↓

• Pace (response - next signal): slowPace (response - next signal): slow

• Initially learn material: allow more time and practiceInitially learn material: allow more time and practice

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Mental WorkloadMental Workload

Purpose:Purpose:• Allocating functions and tasks Allocating functions and tasks between humans and machinesbetween humans and machines

• Comparing alternative equipment and task designsComparing alternative equipment and task designs

• Monitoring operators to adapt . . . Monitoring operators to adapt . . .

• Choosing operatorsChoosing operators

(cont.)(cont.)

Mental WorkloadMental Workload ConceptConcept amount of resources available (within a person)amount of resources available (within a person) － － amountamount of resources demanded (by the task situation)of resources demanded (by the task situation) Measurement Measurement

• Criteria Criteria Sensitivity Sensitivity SelectivitySelectivity Interference: Interference: Not interfere with the performance of the taskNot interfere with the performance of the task ReliabilityReliability Acceptability Acceptability

(cont.)(cont.)

Mental WorkloadMental Workload Measurement Measurement

• Primary task measures Primary task measures Time required / Time availableTime required / Time available (e.g.) SWAN(e.g.) SWAN 缺點缺點 : : 沒考慮 沒考慮 time-shared, cognitive demandstime-shared, cognitive demands Workload Index (W/INDEX)Workload Index (W/INDEX) 考慮 考慮 time-shared; conflict matrixtime-shared; conflict matrix Primary task workload marginPrimary task workload margin changing a parameter of the task changing a parameter of the task 直到工作表現無法維持在事先設定的效標水準直到工作表現無法維持在事先設定的效標水準 問題：問題： task-specific, task-specific, 無法比較不同的工作 無法比較不同的工作

(cont.)(cont.)

Mental WorkloadMental Workload Measurement Measurement

• Secondary task measures: Secondary task measures: spare capacityspare capacity Maintain primary task at some levelMaintain primary task at some level 測 測 2ndary task 2ndary task 之表現之表現 Loading task techniqueLoading task technique devote all necessary resource to 2ndary taskdevote all necessary resource to 2ndary task 測 測 primary task primary task 之表現之表現 2ndary task: time-estimation 2ndary task: time-estimation 最有效 最有效 (sensitive)(sensitive) attention demand↑attention demand↑→→ time estimation (pass of time)↓ time estimation (pass of time)↓ 缺點：測 缺點：測 primary task or primary task or primary task interfered with by the secondary task primary task interfered with by the secondary task

(cont.)(cont.)

Mental WorkloadMental Workload Measurement Measurement

• Physiological measuresPhysiological measures (single-resource model) information processing (single-resource model) information processing 涉及 涉及 CNSCNS

Pupillary responsesPupillary responses difficulty↑difficulty↑→ → dilation responsedilation response↑ ↑ Fig 3-5Fig 3-5

P300 (event-related brain potential, ERP)P300 (event-related brain potential, ERP) difficulty↑difficulty↑→ → P300P300↓ ↓ 缺點：缺點： bulky equipmentbulky equipment not isolate the specific stages being loaded bynot isolate the specific stages being loaded by primary task (except P300) primary task (except P300)

(cont.)(cont.)

Mental WorkloadMental Workload Measurement Measurement

• Subjective measuresSubjective measures UnidimensionalUnidimensional Multidimensional: time loadMultidimensional: time load mental effort loadmental effort load psychological stresspsychological stress

(cont.)(cont.)

Mental WorkloadMental Workload Evaluation Evaluation

• Moray (1988)Moray (1988) Behavioral measure: disorganizedBehavioral measure: disorganized Physiological: no practical usePhysiological: no practical use Subjective:↑Subjective:↑ Theory:Theory: 尚未尚未 Lack of: reliability, consistent correlation between different approachesLack of: reliability, consistent correlation between different approaches

• Dissociate: Dissociate: 不同測量方式得到不同結果不同測量方式得到不同結果 Subjective measure: sensitive to no. of current tasksSubjective measure: sensitive to no. of current tasks Task performance: Task performance: sensitive to degree of competition for common resourcessensitive to degree of competition for common resources (end)(end)

Human Factors in the Information Human Factors in the Information RevolutionRevolution

Expert SystemExpert System Natural Language Interface Natural Language Interface

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