HCI-2025-S1-Wk2

Theories: Purpose

• Based on Shneiderman's work, theories serve several key purposes:

  • Explain: They describe how something works based on evidence and observation.

  • Predict: They forecast potential outcomes.

  • Classify: They categorize and structure items.

  • Clarify: They provide clarity by explaining complex concepts in simpler terms.

Summarize: They distill information into concise statements that highlight the main points.

이론: 목적

• 슈나이더만의 연구에 따르면 이론은 몇 가지 중요한 목적을 수행합니다.

  • 설명: 증거와 관찰을 바탕으로 어떤 것이 어떻게 작동하는지 설명합니다.

  • 예측: 잠재적인 결과를 예측합니다.

  • 분류: 항목을 분류하고 구조화합니다.
    

1. Task-Artefact Cycle: The Evolution of Work and Technology (Carroll, Kellog, & Rosson, 1991)

• This theory posits that users, tasks, and artifacts are interconnected and influence each other.

• Key Components:

  • Tasks

  • Artifacts

  • Requirements and design ideas

  • Adoption, appropriation, use, and possibilities

• Explanation: The cycle explains how users continuously learn and adapt to new tasks and artifacts.

• Influence: Artifacts shape user behavior, either facilitating or hindering performance.
  

1. 작업-인공물 주기: 작업과 기술의 진화 (Carroll, Kellog, & Rosson, 1991)

• 이 이론은 사용자와 작업, 그리고 인공물이 상호 연결되어 서로에게 영향을 미친다고 가정합니다.

• 주요 구성 요소:

  • 작업

  • 인공물

  • 요구 사항 및 디자인 아이디어

  • 채택, 전유, 사용 및 가능성

• 설명: 이 주기는 사용자가 새로운 작업과 인공물에 지속적으로 배우고 적응하는 방식을 설명합니다.

• 영향: 인공물은 사용자 행동을 형성하며, 성능을 촉진하거나 저해할 수 있습니다.

2. Human Error Analysis (James Reason)

• Core Principle: Human error is a symptom of deeper systemic problems, not the root cause.

• Key Points:

  • Human error is inevitable due to human fallibility.

  • Error is a consequence, not a cause; systemic factors should be investigated.

  • Systems can be designed to prevent or mitigate errors by addressing underlying causes.

• Importance:

  • Shift from blaming individuals to understanding systemic issues.

  • Design systems that account for human fallibility.

  • Promote continuous learning and improvement based on error analysis.

• Taxonomy of Errors:

  • Category 1: Unintentional actions from attentional lapses or motor skill failures.

  • Category 2: Failures of attention or memory leading to errors.
    

2. 인간 오류 분석 (James Reason)

• 핵심 원칙: 인간의 오류는 근본 원인이 아니라 더 깊은 시스템 문제의 징후입니다.

• 주요 사항:

  • 인간의 오류는 인간의 불완전성으로 인해 불가피합니다.

  • 오류는 원인이 아니라 결과입니다. 시스템적 요인을 조사해야 합니다.

  • 근본 원인을 해결하여 오류를 예방하거나 완화하도록 시스템을 설계할 수 있습니다.

• 중요성:

  • 개인을 비난하는 것에서 시스템 문제를 이해하는 것으로 전환합니다.

  • 인간의 불완전성을 고려하는 시스템을 설계합니다.

  • 오류 분석을 기반으로 지속적인 학습과 개선을 촉진합니다.

• 오류 분류:

  • 범주 1: 주의력 저하나 운동 기술 실패로 인한 의도치 않은 행동.

  • 범주 2: 주의력 또는 기억력 저하로 인한 오류.
    

3. Norman’s Seven Stages of Action Model

• This model applies to User Interface Design (UID) and the design of everyday things.

• It's a high-level, abstract, and technology-independent theory.

• Key Concepts:

  • Gulf of Execution: Mismatch between user intention and available actions.

  • Gulf of Evaluation: Mismatch between system representation and user expectations.

• Predictive Power: Models and theories should predict outcomes based on adherence or non-adherence.

• Possible Points of Failure:

  • (i) Inadequate goal formation by the user.

  • (ii) Difficulty finding the correct interface object due to incomprehensible labels or icons.

  • (iii) Inability to specify or execute a desired action.

  • (iv) Receiving inappropriate or misleading feedback.

• Failures (ii)-(iv) can be mitigated through improved design or user experience.

• Human Error Levels:

  • Low-level: Slips of execution, misperceptions.

  • Mid-level: Problems in translating to machine input/output (I/O).

  • High-level: Inability to conceive or recognize goal satisfaction.

• Human Error Examples:

  • Inability to produce understandable input or misinterpretation by the machine (e.g., mode errors).

  • Inability to understand or misinterpret machine output (e.g., mindset).

  • Inability to determine the correct action or making the wrong choice.

  • Uncertainty about outcomes or mistaken beliefs about progress toward goals.

4. Skills, Rules, and Knowledge (SRK) – Process (Rasmussen, 1983)

• Levels of Cognitive Control:

  • Skills-Based Behavior (SBB):

    • Automatic and unconscious actions through muscle memory.

    • Highly practiced and routine tasks.

    • Requires minimal cognitive attention.

  • Rule-Based Behavior (RBB):

    • Conditional and context-dependent actions following established rules or procedures.

    • Less automatic, requiring more cognitive attention and conscious decision-making.

    • Dependent on stored knowledge like procedures, protocols, or guidelines.

  • Knowledge-Based Behavior (KBB):

    • Conscious and analytical thinking used to solve novel or complex situations.

    • Highly cognitive and attention-demanding, actively processing information and making decisions.

    • Dependent on mental models, which are internal representations of the system, task, or situation.

• Signals, Signs, and Symbols:

  • Signals: Sensory data representing time-space variables in the environment.

  • Signs: Indicate a state in the environment, activating stored patterns of behavior.

  • Symbols: Abstract constructs representing other information, variables, relations, and properties, related to a formal structure of relations and processes.

• Implications:

  • Familiar signals, signs, and symbols lead to shortcuts and adaptability.

  • Unclear signals and signs require knowledge-based behavior, engaging mental models.

• SRK: Implications for Design:

  • Design Principles (Norman):

    • Visibility: Make system behavior and constraints visible.

    • Affordance: Design the system to afford intended actions.

    • Feedback: Provide timely and relevant feedback.

    • Consistency: Maintain consistent behavior and interface.

    • Error Tolerance: Design for tolerance of user errors.

  • Ecological Interface Design: Representation of processes to facilitate diagnosis and decision-making.

5. Object-Action Interface (OAI) Paradigm (Shneiderman, 1998)

• The OAI paradigm is a model for understanding how a windows GUI works or how one interacts with it.

• OAI model: select an object, then choose an action to perform on it.

• AOI model: specify an action and then specify the object e.g. copy <Source File> <Destination File>.

• This distinction became important when we changed from command line interfaces to direct manipulation interfaces; and significantly affected usability.

• Key Differences:

  • Action-Object Interfaces (e.g., command line): Requires syntactical knowledge, recognition vs. recall, high memory load, and extensive training.

  • Object-Action Interfaces (e.g., GUI): Permissible actions are associated with the object, visibility is crucial, and commands should be harmonized with the user task.

• Implication for System Designers: Discover menu or dialog structure meaningful to users by:

  • (i) Decomposing the task

  • (ii) Organizing the actions

  • (iii) Mapping the information (information architecture)

  • (iv) Structuring the functions

6. Keystroke-Level Model (KLM) (Card, Moran, & Newell, 1980)

• The Keystroke-Level Model (KLM) predicts how long it will take an expert user to accomplish a routine task without errors using an interactive computer system.

• Operators:

  • Physical Motor Operators:

    • K (keystroke or button press)

    • P (pointing to a target on a display with a mouse)

    • H (homing the hand(s) on the keyboard or other device)

    • D (drawing (manually)

  • Mental Operators:

    • M (mentally preparing for executing physical actions) for thinking and decision making

  • System Response Operator:

    • R (response time of the system)

• Operator Details & Time (sec):

  • K (keystroke): Time based on typing skill (e.g., 0.08 for 135 wpm, 0.50 for random letters).

  • P (pointing): 1.1

  • H (homing): 0.4

  • D (drawing): 0.9n + 0.16

  • M (mental): 1.35

  • R (system response): System dependent.

• Example:

  • Click Link/Button: 3.73

  • Pull-Down List (No Page Load): 3.04

• Heuristics for Placing the M Operator
  *Rule 0: Place Ms in front of all Ks that are not part of argument strings proper (e.g., text strings or numbers).

• Rule 1: Place Ms in front of all Ps that select commands (not arguments).

• Rule 2: If an operator following an M is fully anticipated in the operator just previous to M, then delete the M (e.g., PMK -> PK).

• Rule 3: If a string of MKs belong to a cognitive unit (e.g., the name of a command), then delete all Ms but the first.

• Rule 4: If a K is a redundant terminator (e.g., the terminator of a command immediately following the terminator of its argument), then delete the M in front of the K.

• Rule 5: If a K terminates a constant string (e.g., a command name), then delete the M in front of the K; but if the K terminates a variable string (e.g., an argument string) then keep the M.

7. GOMS (Card, Moran, & Newell, 1983)

• Goals, Operators, Methods and Selection rules

• The model postulates that:

  • Users formulate goals (e.g. to edit a document) and sub-goals (insert word)

  • Each of which is achieved by using methods or procedures (e.g. move cursor to desired location by following a sequence of arrow keys)

  • Operators are “elementary perceptual, motor or cognitive acts, whose execution is necessary to change any aspect of the user’s mental state or to affect the task environment” (Card et al, 1983, p144)

  • Selection rules are the control structures for choosing among the several methods available for accomplishing a goal (e.g. delete by repeated backspace versus delete by placing markers at beginning and end of region and pressing delete button)

• Advances on KLM

8. Fitts’ Law (Fitts, 1954)

• States that the time to acquire a target is a function of the distance and the size of the target

• Formula: MT = a + b * Log2(2A/W)

• MT - The movement time

• a - The intercept

• b - The slope

• D - The distance between the origin and the target

• W- The width of the target

• Fitts' Law tells us the following:

  • Movement time (MT) increases as the movement amplitude (A) increases.

  • MT increases as the aiming accuracy requirement increases, that is, as target width (W) decreases.

  • MT is essentially constant for a given ratio of movement amplitude (A) to target width (W).

  • These principles are valid for a wide variety of conditions, participant variables, tasks or paradigms, and body parts used.

9. Miller’s Law (Miller, 1956)

• A person can keep 7 ± 2 items in working memory

• Chunking - the recoding of smaller units of information into larger, familiar units

• expectations, (prior) knowledge in the head / world and familiarity => semantic value vs. random