Norman vs. GOMS Comparison Table
| Norman’s Stage | Real-World Example (iPhone 13 / Samsung S25) | GOMS Interpretation & Rationale GOMS 1983 vs. Norman’s 1988 |
Alignment Analysis |
|---|---|---|---|
|
Goal ↔ GOAL (User intention) |
“I need Wi-Fi ON to access the internet.” |
✅ Goal: Enable-Wi-Fi. Top-level objective in GOMS. Both Goal and Methods are “intentions,” but at different levels of abstraction. |
✅ Perfect Match Direct correspondence between models. |
|
Plan ↔ METHOD & Selection Rules Mental state before action or High level of intention Cognitive decision state before execution |
Decision (Cognitive Step): “I’ll use the quick toggle.” Note: GOMS typically models a single dominant method for simple, routine tasks. If multiple methods were modeled, Selection Rules would formally encode the choice logic that Norman lumps under “Planning.” User implicitly prefers quick toggle over Settings due to efficiency. |
✅ Method & Selection Rules: • iPhone: Swipe down → Control Center → Wi-Fi • Samsung: Swipe down → Quick Panel → Wi-Fi Selection Rule (optional): If device is unlocked → use Quick-Toggle-Method. Used only when multiple methods are explicitly modeled. |
✅ Conceptual Match Both models represent high-level action planning. Norman’s “Plan” is realized as the GOMS “Method.” The choice aspect is implicit in GOMS for simple cases, explicit as Selection Rules for complex ones. 🟡 Contextual Alignment — Handled implicitly in Norman; explicit but optional in GOMS. |
| Specify |
Visual search & targeting: User locates (finds) the fan-shaped Wi-Fi icon among other toggles. Specification is about perception and meaning, not timing. |
Not Explicitly Modeled. GOMS assumes the correct UI object is already known. KLM may include mental preparation. KLM’s [M] operator ≠ Norman’s Specify. |
Key Divergence This is cognitive work Norman explains. GOMS abstracts this cognitive work away rather than modeling it explicitly, OR as part of a mental operator [M] in Execute/Operator. |
| Execute ↔ OPERATOR |
Physical Action: Finger taps the Wi-Fi toggle. • Touchscreen tap duration: ~0.2 seconds (KLM: [K] or [B]). |
Operator: Tap (or click). This is a primitive, timed motor action. KLM Sequence: [M][P][K] • [M]: Mental prep to point (~1.35s) • [P]: Point to icon (~1.1s) • [K]: Keystroke/tap (~0.2s) |
✅ Direct Match This is the empirical core both models acknowledge. |
| Perceive / Interpret / Evaluate |
Feedback Loop: 1. Perceive: Toggle color changes (grey → blue). 2. Interpret: “Blue = ON; connection active.” 3. Evaluate: Wi-Fi icon appears in status bar; internet works. |
Not Modeled in GOMS. GOMS assumes perfect perception, instant interpretation, and automatic goal satisfaction. No time cost or cognitive stage is allocated. |
Fundamental Divergence This is the heart of Norman’s model (closing the Gulf of Evaluation) and is entirely outside GOMS’s scope. |
Quick Note
This page is included as a conceptual reference for Lab 01. Students should focus on writing clean, semantic HTML and be able to explain how their structure supports usability and accessibility.