HCI Introduction Midterm Exam Summary - From HCI 3.0 to Interface Design

I read through and condensed all the slide text from the six lecture material decks (Chapters 1, 3, 6, 9, 11, and 13). The scope is strictly limited to the full text of the slides from the textbook Introduction to HCI (by Jinu Kim, Yonsei University HCI Lab & HAII).

Exam Information - Original Announcement

"The exam scope covers up to Week 10: Business Models. It consists of 6 multiple-choice questions and 7 short-answer questions. The exam will be conducted in a closed-book format. The exam venue is Room 405, Sanyong Building. Please arrive early enough for the exam to start by 10:00 at the latest." (Posted on October 23, 2026)

The midterm grade accounts for 30% of the final grade, and it is confirmed as an offline exam, meaning there is no online option. Since the announcement does not specify the exact exam date, please verify it separately.

A quick note on interpreting the scope: "Up to Week 10: Business Models" refers to the schedule table in the syllabus. However, the provided materials consist entirely of decks for Chapters 1, 3, 6, 9, 11, and 13. As there is no definitive basis for determining which chapters will appear on the exam, I have summarized all of them.

Chapter 1: Understanding HCI 3.0

HCI is the creation and evaluation of Digital Artifacts that are useful, usable, and fun for people. The ultimate goal is developing high-quality digital products, services, and content that provide the optimum experience. The text also cites Herbert A. Simon’s The Sciences of the Artificial: "Observing how people actually make and use something is the most appropriate study of humanity."

Aspect	HCI 1.0	HCI 2.0	HCI 3.0
Focus	Fragmented interaction between a single user and computer	User experience with multiple users and social media	Human-AI Interaction = HAII
Interface	Text-based (without GUI)	GUI and mouse	Natural interaction (NLP, voice, gesture)
Features/Scope	Functional aspects, command input, high learning curve, one-to-one	Behavioral/psychological elements like scrolling and empathy (likes), multiple users	Collaboration and shared value with AI, individual/group/AI agents

Sensing–Reasoning–Actuating

AI-enabled systems shift from passive to active, learning and acting on their own. Since direct user intervention is often unnecessary, processes flow faster.

Stage	Function	Interaction Point	Example
Sensing	Collecting data required by AI	Precise data collection + providing specific descriptions to assist AI	Mind Garden: Camera sensor for Heart Rate Variability (HRV), etc.
Reasoning	Situating context via data and deriving optimal solutions	Interactive Machine Learning (IML), presented in an easy-to-understand format	Interpreting data to provide patterns
Actuating	Predicting situations and guiding user behavior	Since predicting all situations is impossible supplementation via human expertise	Altsgard: Agent "Sammy," brain training

Digital Health

Composition = Digital Biomarkers (DBM) + Digital Therapeutics (DTx). The key point is that these two cannot exist without Artificial Intelligence.

• Digital Biomarkers: Indicators that objectively measure and analyze physiological and behavioral data obtained through devices such as smartphones and wearables, used for diagnosis, monitoring, and personalized treatment.
• Digital Therapeutics: Evidence-based software programs designed to prevent, manage, or treat medical conditions or disabilities.

Three Types of DTx: Standalone (e.g., standalone Cognitive Behavioral Therapy), Augmentary (used in conjunction with existing treatments to enhance efficacy), and Complementary (supplements existing treatments, aids self-management and lifestyle improvement). Examples include Nightware (learning sleep habits) and Anzeilax (data refinement via deep learning).

Memory Aid: The ultimate goal is Real Experience (Dewey & Martin, 1934). The three fundamental elements are Usability, Usefulness, and Reliability. UX design consists of four stages: Analysis, Planning, Design, and Evaluation.

Chapter 3: HCI 3.0 and Usefulness

• Usefulness: A principle that helps effectively achieve the purpose of use. Focuses on achieving the goal, even if the process is difficult.
• Usability: The usage process must be efficient - "Even if it's slightly inconvenient, [do it] for infection prevention!"

The same portal differs based on purpose: Google = Searching, Naver = Browsing. By domain: Mobility = Safety, Finance = Security, Healthcare = Safety & Efficacy.

Problem Space ↔ Solution Space

Problem Solving = Exploring from initial state → goal state using operators within path constraints. The problem space is the set of all solvable states, while the solution space is the set of all alternatives that provide a solution.

Problem Space Element	Corresponding Analysis
Initial State (User's current state)	Stakeholder Analysis
Goal State (State to be reached)	Task Analysis
Constraints (Environmental influence)	Context Analysis
Operators (Available features)	Context Analysis

Usefulness = Consistency between the problem space representation and the solution space mental model. A conceptual model is an abstraction of structure and operation (e.g., company org chart), defined by Liddle (1996) as simplification.

Four Types of Mental Models

Mental Model = The user's Conceptual Model of the system inside their head. It is a mental knowledge structure that simply abstracts structure and dynamic operation.

Mental Model	Content	Keyword
Value Model	What value it is expected to provide	User Purpose
Structure Model	Description of what specific elements it comprises	Information Architecture
Function Model	How it is used	User flow
Representation Model	Visualization of visual information	User Interface

In HCI 3.0, AI is prone to anthropomorphism because it is perceived as acting in a "human-like manner." A representative illusion is the belief that "everything should be handled automatically." It is important to distinguish between values that can and cannot be provided.

Need = A necessity to improve dissatisfaction ("Eating bread resolves hunger"), Want = A desire for satisfaction beyond the minimum, similar to the concept of value.

Value	Concept	Example
Utilitarian	Tool for practical purposes/needs	Medication management robot Priya
Hedonistic	Emotional satisfaction/enjoyment	Game-like ADHD treatment EndeavorRx by Akili

Efficacy vs. Suitability

Aspect	Efficacy	Suitability
Environment	Controlled experimental environment	Real-World Practice (RWP)
Proof	Proving health benefits numerically and safety (Risk)	Proving requirement fulfillment via data on accuracy, specificity, reliability, and scope of use

These two are in a trade-off relationship, making it difficult to maximize both simultaneously. Finding a balance is the role of an HCI expert.

SaMD = Software as a Medical Device: Independent software that is not dependent on hardware for its own medical purpose, used for diagnosis, treatment, and observation (Independence, use of general-purpose platforms). Efficacy classification (Korea health Industry Development Institute, 2019): Therapeutic function / Risk detection through monitoring / Convenient chronic disease management / Indirect support for diagnosis/screening. Example: ForMe is a voice-based tablet service for enhancing Executive Function in children with ADHD.

Chapter 6: Stakeholder Analysis

Stakeholder = A person who has a direct or indirect stake in a product/service (Client, user, consumer, project manager, etc.). Analysis is the first step in understanding the "user's problem space," analyzing the initial state. Kirby (1991): In a broad sense, at an appropriate level according to priority. Procedure: ① Preparation → ② Socio-Technical Model → ③ Persona Model.

3 Steps of Preparation: ① Identification (patient, doctor, insurance company, government, etc.) ② Characteristics (Primary users = actual interaction; Secondary users = those who influence/are influenced) ③ Four types of impact (Clinical, Cost, Task, Social Value). Cost analysis: CMA (Cost-Minimization), CEA (Cost-Effectiveness), CUA (Cost-Utility), CBA (Cost-Benefit). Priority levels: Essential, Important, Consider, Reference.

Socio-Technical Model

A model that considers both social and technical factors simultaneously, as technology is created within an organizational environment. Methodologies: USTM, CUSTOM, OSTA, ETHICS, SSM.

1. Collective Investigation - Interviews (in-depth, focus group, contextual) + Observation (photo diary, town watching, culture probes, shadowing)
2. Root Definition - Beneficiaries, ecological changes, acceptance, usage environment
3. Conceptual Model - Solid line = strong relationship, Dotted line = weak relationship
4. Evaluation - Stakeholder validation + Ecosystem validation (the biggest reason for creation)

Persona

The etymology is the mask of Greek theater, and Carl Jung defined it as an "external personality." Definition: A fictional person representing diverse