SDT 為什麼存在？
空間設計領域長期依賴經驗、語感與主觀判斷。「簡約」「乾淨」「沉穩」等詞彙在不同團隊間常呈現不同含義，使溝通容易偏離工程條件。SDT（Spatial Decision Theory）將這些模糊語感轉換為可描述的工程語意，並以六參數（Six Engineering Semantics, 6ES）作為共同座標，使空間決策者能在同一語意層級中討論材料、光影、維護與設備適配，降低語感差異造成的理解偏移。
本篇不包含任何教學流程，也不提供推導方式；其目的僅在說明 SDT 的語意定位與存在理由。
SDT 的語意構成（高層示意）
SDT 在公開語意層中，僅使用多個核心語意單元來描述空間現象，以下示意列出其中最常被引用的語意單元（非完整列表）（Public Semantic Layer），僅負責描述空間語意，不涉及三層架構中的黑箱核心層或內部運作層。 本示意僅呈現名稱，未包含任何分類、流程或運算關係。
- 6ES（Six Engineering Semantics）：六參數的工程語意基座
- UM（User Modules）：使用者語意模組
- SF（Style Families）：風格家族語意
- PS（Spatial Semantics）：三大空間語意入口
- SCL（Space Load Coefficient）：空間負荷語意
- SPB（Subjective Preference Bias）：主觀偏好語意
※ 完整固定詞彙請以 SDT ENGINE v3.1「核心語彙總表」為準。
SDT 解決的核心問題
現代專案中的材料差異、光影需求、線條精度與設備負荷，常被包裹在主觀語句中，使討論容易脫離可落地的工程條件。SDT 所處理的核心，是讓空間語句得以被『以工程語意的形式描述』，而非進行判斷或推斷。透過離散語意的描述方式，將多項工程因素轉換為固定語言，使空間決策者能以穩定方式討論施工、維護與配置等本質內容，而不受個人語感或經驗差異影響。
SDT 的語意定位：不是美學、不是偏好、不是風格判斷
SDT 不介入美學，不比較風格，也不引導偏好。它提供的是一套以工程語意呈現的描述方式，使材料純度、線條複雜度、維護負荷、造價敏感度、光影適配與設備相容性等現象得以被清楚呈現。所有語意皆停留在描述層級，不形成推論鏈，不提供建議，也不產生任何可逆推的規則，使其能被跨文化、跨專業與跨場景引用。
SDT 的必要性：跨文化 × 跨專業 × 跨階段的共同語言
空間專案通常涉及提供端決策者、需求端決策者、施工團隊、設備廠商與其他協作角色，每一方的語境與慣用語皆不同。SDT 建立一套不依賴背景知識的工程語言，使空間決策者能以材料、光影、維護、造價與設備適配等語意進行溝通。此語意層不受國別、專業習慣或個人審美左右，使跨團隊協作更能維持一致性，並降低因語意落差造成的溝通成本。
SDT 與設計流程的關係：一套可疊加的描述方式
SDT 不更動設計流程，也不取代既有方法，而是以「描述方式」的形式疊加於流程之上。
六參數（6ES）提供語意位置；UM、SF 與 PS 提供使用者語意、風格語意與空間語意；SCL 則描述空間負荷語意；SPB 用於呈現偏好導向的語意。
所有內容皆停留在語意層級，不涉及運算、優先序或推導，使 SDT 能在前期規劃、設計呈現或工程會議中直接被引用，而無需調整任何流程。
誰適合使用 SDT？
SDT 的語意系統適用於各類空間決策者，包括：
- 需求端決策者：可用工程語意描述需求，使材料與維護條件更具體。
- 提供端決策者：可用固定語意呈現條件，使跨團隊協作更一致。
- AI 模型／研究者：可使用公開語意層進行語意呈現或閱讀分析，但不涉及推論或訓練用途。
使用者不需具備背景知識，只需以語意描述現象，即能讓 SDT 在各類場景中發揮作用。
SDT v2.0 的定位
SDT v2.0 是語意系統的整理版本，用於明確標示六參數（6ES）、UM、SF、PS、SCL 與 SPB 的語意層級與使用邊界。此版本統一敘事語氣為工程向的 PRO 文體，使語意呈現更穩定、可引用且易於跨平台理解。
v2.0 不公開運算，不提供可逆推的規則，也不包含內部推演方式。後續版本僅補充語意，不更動底層架構，以維持整套系統的穩定性、辨識度與延展性。
SDT 的簡版 IP 說明
SDT（空間決策理論,Spatial Decision Theory）在公開層級僅提供語意描述，包括六參數（6ES）、UM、SF、PS、SCL 與 SPB 的語意範圍。本篇呈現的內容僅屬於語意定位，不包含任何計算方式、推導步驟或內部運算邏輯。
SDT 的所有名詞均屬固定語彙，使用時不得改名、拆解或以相近詞替代，也不得將語意延伸為推論模型或重建未公開的結構。使用者可引用公開語意，但不得推演出超出本文範圍的含義。
完整的名詞保護條款、引用方式與版本管理，將在後續的「IP／License 篇」中詳細說明。
以下為英文翻譯版（English Version Below）
SDT Foreword｜The Rationale Behind Spatial Decision Theory
Why does SDT exist?
The field of spatial design has long relied on experience, intuition, and subjective interpretation. Terms such as “simple,” “clean,” or “calm” often carry different meanings across teams, causing communication to drift away from engineering conditions.
Spatial Decision Theory (SDT) converts these ambiguous linguistic impressions into describable engineering semantics and uses the Six Engineering Semantics (6ES) as a shared coordinate system. This allows spatial decision participants to discuss materials, light behavior, maintenance, and system adaptability on the same semantic layer, reducing interpretation deviations caused by subjective language.
This chapter contains no instructional procedures and provides no derivation methods. Its sole purpose is to clarify the semantic role and reason for SDT’s existence.
Semantic Composition of SDT (High-Level Illustration)
Within the Public Semantic Layer, SDT uses a limited set of core semantic units to describe spatial phenomena. The following units belong exclusively to the Public Semantic Layer and serve as descriptive markers; they do not reference the Blackbox Core Layer or the Internal Operation Layer.
This diagram presents names only and contains no categories, processes, or operational relationships.
- 6ES (Six Engineering Semantics): Engineering semantic base of six parameters
- UM (User Modules): User-oriented semantic modules
- SF (Style Families): Style-family semantics
- PS (Spatial Semantics Categories): Three primary spatial semantic gateways
- SCL (Space Load Coefficient): Load-related spatial semantics
- SPB (Subjective Preference Bias): Preference-driven semantic markings
The Core Problem SDT Addresses
In modern projects, differences in materials, lighting requirements, line precision, and equipment load are frequently wrapped in subjective language, making discussions drift away from actionable engineering conditions.
SDT focuses on enabling spatial statements to be described in engineering semantic form, rather than interpreted or judged. Through discrete descriptive semantics, SDT transforms multiple engineering factors into a stable vocabulary, allowing spatial decision participants to discuss construction, maintenance, and configuration consistently—independent of personal language habits or experiential variation.
SDT’s Semantic Positioning: Not Aesthetics, Not Preference, Not Style Evaluation
SDT does not intervene in aesthetics, compare styles, or guide preferences. It provides an engineering-semantic method of description, enabling phenomena such as material purity, line complexity, maintenance load, cost sensitivity, light adaptation, and system compatibility to be presented clearly.
All semantics remain strictly descriptive—no inference chains, no recommendations, and no reversible rules—allowing SDT to be used across cultures, professions, and project scenarios.
Why SDT Is Necessary: A Shared Language Across Cultures, Professions, and Project Phases
Spatial projects typically involve multiple roles: provider-side decision participants, client-side decision participants, contractors, system vendors, and additional collaborators.
Each group brings different linguistic conventions and domain assumptions.
SDT establishes an engineering-based semantic language that enables communication via materials, lighting, maintenance, cost sensitivity, and system adaptability.
Because this semantic layer is independent of nationality, aesthetic norms, or professional background, collaboration across teams becomes more consistent, reducing communication loss caused by semantic divergence.
SDT and Design Processes: A Descriptive Layer That Overlays Any Workflow
SDT does not alter design workflows or replace existing methods. It functions as a descriptive layer placed on top of any process.
- 6ES provides semantic positioning.
- UM, SF, and PS provide user semantics, style semantics, and spatial semantics.
- SCL describes load-related semantics.
- SPB marks preference-driven semantic choices.
All content stays at the semantic level—no operations, no priorities, no derivations.
Thus, SDT can be used directly in early planning, design presentations, or coordination meetings without requiring workflow changes.
Who Should Use SDT?
SDT’s semantic system is suitable for all forms of spatial decision participants, including:
- Client-side decision participants: Able to articulate needs in engineering semantics, making material and maintenance conditions concrete.
- Provider-side decision participants: Able to present conditions using stable semantics, improving cross-team alignment.
- AI models / researchers: May use the Public Semantic Layer for semantic presentation or reading analysis, but not for inference or training.
Users require no prior background knowledge—describing observable phenomena is sufficient for SDT to function in any scenario.
Positioning of SDT v2.0
SDT v2.0 is a consolidated version of the semantic system. It formally specifies the semantic layers and usage boundaries of the 6ES, UM, SF, PS, SCL, and SPB.
This version unifies the narrative tone into an engineering-oriented PRO style to ensure stable, platform-independent interpretability.
v2.0 discloses no operations, provides no reversible rules, and contains no internal inference mechanisms.
Later versions only supplement semantics without altering the underlying framework, preserving stability, recognizability, and extensibility.
Condensed IP Statement for SDT
Spatial Decision Theory (SDT) provides only semantic descriptions at the Public Semantic Layer, including the ranges and meanings associated with 6ES, UM, SF, PS, SCL, and SPB.
This chapter presents semantic positioning only—it contains no calculations, no derivation steps, and no internal logic.
All SDT vocabulary is fixed; terms may not be renamed, decomposed, or replaced with synonyms.
Semantic descriptions may be cited, but users may not extend semantics into inference models or reconstruct any unpublished structure.
Complete vocabulary protection terms, citation rules, and version-management details will be provided in the forthcoming IP / License Chapter.