Information Input and Processing

1. Information Input and Processing Chap 3

2. Information Theory Displaying Information Coding of Information Compatibility A Model of Information Processing Fig 3-2 Perception Memory Decision Making Attention Age and Information Processing  Mental Workload  Human Factors in the Information Revolution  Information Input and Processing

3. Displaying Information • Direct vs. Indirect Sensing • Stimuli for Indirect Sensing: Display • Coded stimuli • Reproduced stimuli • Types of Information Presented by Displays • Selection of Display Modality (cont.)

4. Displaying Information • Types of Information Presented by Displays • Quantitative Information • Qualitative Information • Status Information: (ex) on/off, TV channels • Warning and Signal Information • Representational Information: pictorial, graphic • Identification Information: (ex) traffic lane, color-coded pipes • Alphanumeric and Symbolic Information • Time-phased Information:(ex) Morse code, blinker lights (cont.)

5. Displaying Information • Selection of Display Modality • Visual vs. Auditory Tab 3-1 (end)

6. Coding of Information • Coding: original stimulus information converted to a new form and display symbolically • 分類: • Stimulus dimension: single vs. multiple • Utility: identify vs. distinguish • Absolute vs. Relative Judgments • Absolute: identify, comparison in memory • Relative: distinguish (same or different) (cont.)

7. Coding of Information • Making Absolute Judgments along Single Dimensions: Tab 3-2 • Fewer discrimination than relative • 7 ±2 (limitation of human memory) • Making Absolute Judgments along Multiple Dimensions • Orthogonal: independent,＜ product of single • Redundant: not independent,＜ orthogonal (cont.)

8. Coding of Information • Characteristics of a Good Coding System • Detectability of Codes • Discriminability of Codes • Meaningfulness of Codes • Standardization of Codes • Use of Multidimensional Codes (end)

9. Compatibility • Compatibility: relationship of stimuli and responses to human expectation • Types of Compatibility • Conceptual Compatibility • Meaningfulness of Codes & symbols: (ex) airport: aircraft symbol vs. green square • Meaningful Abbreviations: (ex) commands (computer) • Movement Compatibility • Spatial Compatibility • Modality Compatibility (cont.)

10. Compatibility • Types of Compatibility • Modality Compatibility Fig 3-1 • Input: Auditory (speech) Visual (display on screen) • Output: Spoken response Manual response • Task: Verbal: A/S Spatial: V/M (cont.)

11. Compatibility • Origins of Compatibility Relationships • Intrinsic in the situation (e.g. isomorphic) • Culturally acquired • Identification of Compatibility Relationships • Obvious (e.g. spatial), but check out the generality • Empirical exp. • Discussion • Empirically, not self-evident • Not universal • Trade-off (end)

12. Attention • Selective Attention • Focus Attention • Divided Attention • Sustained Attention (cont.)

13. Attention • Selective Attention • Load stress vs. Speed stress • Guideline: p.71 • Few channels • Provide information: relative importance • Reduce the overall level of stress • Preview information • Training: optimal scan patterns • Close together • Auditory: do not mask one another • Stimuli separated temporally, self-paced (cont.)

14. Attention • Focus Attention • Proximity of the sources:  • Distinct:  • Guidelines: attended channel vs. competing channels (p.72) • Distinct • Separate (in physical space) • Reduce of no. of competing channels • Salient: larger, brighter, louder, centrally located (cont.)

15. Attention • Divided Attention: time-sharing • Single-Resource Theories • Multiple-Resource Theories(Wickens, 1984) • Stages: Perceptual and central processing vs. Response selection and execution • Input modalities: Auditory vs. Visual • Processing codes: Spatial vs. Verbal • Responses: Vocal vs. Manual response –– driving a car while talking on the telephone (cont.)

16. Attention • Divided Attention: time-sharing • Guideline:p.74 • Dissimilar: stages, input modalities, . . . • Number of potential sources of information↓ • Relative priorities • Difficulty level ↓ • Learning of the manual task↑(automatic) –– 儘可能降低難度 (cont.)

17. Attention • Sustained Attention • Vigilance decrement 20-35 min (lab), Exponential Fig 3-4 • Guideline: p.75-76 • 降低疲勞 work-rest schedules, task variation environmental factors: optimal (cont.)

18. Attention • Sustained Attention • Guideline: p.75-76 • Detect signal 難度下降 conspicuity of the signal↑(明顯） uncertainty: where & what↓ training: make clear the nature of the signal 　　呈現 signal之速率↓ • 提高 motivation 　　強調工作的重要性 　　給予 artificial signal, 並給予回饋 (end)

19. Age and Information Processing • Changes in Information Processing Capacity • Slowing performance: central-cognitive, perceptual-motor • Working memory↓(shift of attention) • LTM (transferring)↓ • Difficulty: incompatibility, ambiguous stimuli (cont.)

20. Age and Information Processing • Guideline: • Strengthen signals • Reduce irrelevant details • Compatibility↑ • Time-sharing demand↓ • Pace (response - next signal): slow • Initially learn material: allow more time and practice (end)

21. Mental Workload • Purpose: • Allocating functions and tasks between humans and machines • Comparing alternative equipment and task designs • Monitoring operators to adapt . . . • Choosing operators (cont.)

22. Mental Workload • Concept amount of resources available (within a person) － amountof resources demanded (by the task situation) • Measurement • Criteria • Sensitivity • Selectivity • Interference: Not interfere with the performance of the task • Reliability • Acceptability (cont.)

23. Mental Workload • Measurement • Primary task measures • Time required / Time available (e.g.) SWAN 缺點: 沒考慮 time-shared, cognitive demands • Workload Index (W/INDEX) 考慮 time-shared; conflict matrix • Primary task workload margin 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 • 問題：task-specific, 無法比較不同的工作 (cont.)

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

25. Mental Workload • Measurement • Physiological measures (single-resource model) information processing 涉及 CNS • Pupillary responses difficulty↑→ dilation response↑ Fig 3-5 • P300 (event-related brain potential, ERP) difficulty↑→ P300↓ • 缺點：bulky equipment not isolate the specific stages being loaded by primary task (except P300) (cont.)

26. Mental Workload • Measurement • Subjective measures • Unidimensional • Multidimensional: time load mental effort load psychological stress (cont.)

27. Mental Workload • Evaluation • Moray (1988) • Behavioral measure: disorganized • Physiological: no practical use • Subjective:↑ • Theory:尚未 • Lack of: reliability, consistent correlation between different approaches • Dissociate: 不同測量方式得到不同結果 • Subjective measure: sensitive to no. of current tasks • Task performance: sensitive to degree of competition for common resources (end)

28. Human Factors in the Information Revolution • Expert System • Natural Language Interface (end)