My E-Portfolio based on work carried out on my Msc Program on Artificial Intelligence and Machine Learning at the University of Essex.
This week focuses on introduction to and background of Knowledge Representation and Reasoning, covering introductory chapters and background material.
Reading Marquis, Papini and Prade (2020) expreses how KR isn't just about computers - it's been around since humans started drawing on cave walls with rocks. The journey from Aristotle's logic to modern AI systems is basically the same human need to get knowledge out of our heads and make it useful. It is interesting that we're still asking the same questions Aristotle did: How do we organize what we know?
The Weststeijn (2011) discussion really clicked with this historical perspective. Those Dutch scholars trying to create universal picture languages weren't doing something new, they were continuing what humans have always done, from tally stones to hieroglyphs. Delgrande et al. (2023) are right that the challenges haven't really changed, we've just got better tools now. It made me think about how the ontologies we'll build in Protégé are just the latest chapter in this ancient story.
This unit introduces the underlying principles of reasoning: set theory, logic, and truth tables. Provides exercises for practicing manipulation of sets and truth tables.
Working through the truth tables in Sharma, Lo, and Pilling (2022) made the connection between sets and logic click for me. It's one thing to know that intersection is like AND, but actually building the truth tables shows why it works. The Boolean operations aren't just mathematical abstractions, they're the foundation of how computers think.
Endriss (2021) expresses how Prolog handles sets so naturally. When you write a rule like `member(X, [H|T])`, you're basically doing set theory without thinking about it. The exercises helped me see that the formal notation we learn is just a way to be precise about relationships we already understand intuitively. Makes me think about how much logic we use every day without realizing it's actually formal reasoning.
Explores the concept of reasoning and formal methods of reasoning as building blocks for knowledge representation and reasoning.
The lecture cast was insightful explaining ZFC axioms (empty set, separation, pairing, choice, infinity, power set, union) through to practical applications.Brachman and Levesque (2004) explained how horn clauses and modus ponens aren't just abstract concepts but actual tools that power Prolog's reasoning engine.
It is clear that from Lee (2024) to Minsky's frames from decades ago still influence modern knowledge representation. The progression from positional logic to FOL to semantic nets shows we're building on solid mathematical foundations making the connection between theory and practice much clearer.
This unit introduces logic programming, essential to understanding formal methods such as first order logic. Provides experience writing, running, and evaluating Prolog programs.
Prolog felt backwards at first. Coming from procedural languages, writing `grandparent(X,Z) :- parent(X,Y), parent(Y,Z).` seemed counterintuitive, you declare what's true rather than how to compute it. Working through the animal classification exercise helped, but debugging when rules don't behave as expected proved frustrating. Endriss (2021) chapters 5-6 provided structure, though the theoretical explanations didn't always match the actual implementation.
The unification mechanism from Ritchie (2002) eventually made sense, but backtracking still catches me off-guard. When queries return multiple solutions or fail unexpectedly, it's not always clear why. The logic programming exercises showed both the elegance and the brittleness of declarative approaches, it is powerful when it works, opaque when it doesn't.
Unit 5 focuses on understanding the concept of modeling and knowledge engineering. Explores how to design and create knowledge models, and how to use Protégé as a modeling tool.
Collins (1998) talks about formal methods and how they can be good solution to complex problems. Yun et al. (2021) breaks down the different model types clearly - diagnostic, explorative, analytic, constructive
The knowledge acquisition ties into the scientific method. The progression from RDF to ontologies to SWRL shows how modeling has evolved. Even statistical and probabilistic modeling fits into this bigger picture. It makes case for why we need tools like Protégé to handle all this complexity systematically
This unit focuses on practical application of ontological approaches for developing knowledge-based systems. Applies knowledge gained so far via case study and hands-on Protégé work.
Working through Debellis (2021) with Protégé 5.5 showed how OWL ontologies function in practice rather than just theory. The step-by-step approach helped me understand how competency questions drive the design process. Building knowledge-based systems connected concepts from previous units, though the complexity of the interface took time to navigate effectively.
Solanki (2019) describes knowledge engineering as both art and science, which became apparent through hands-on work. Different modeling approaches serve different purposes depending on domain requirements and user needs. The case study methodology demonstrated connections between ontology building and practical problem solving, though selecting appropriate modeling strategies remains challenging.
This unit focuses on concepts and principles of knowledge acquisition, and approaches to knowledge acquisition and formalism as steps in developing accurate and efficient knowledge-based systems.
The lecture cast covered knowledge acquisition complexity, distinguishing between data, information, and knowledge in practical terms. Different knowledge types (declarative facts, procedural actions, meta-knowledge for expert decisions) require specific elicitation techniques like laddering, sorting, and matrix-based approaches. The structured nature of these methods became apparent when attempting to capture expert knowledge systematically.
Debellis (2021) provides practical guidance while Blagec et al.'s (2022) AI knowledge graph demonstrates large-scale implementation challenges. The formalization process of converting tacit knowledge into structured representations involves ontological commitments that can be difficult to validate. Knowledge engineering requires balancing technical implementation with domain expertise, though the boundaries between art and science remain unclear.
This unit focuses on equipping you with practical skills to design solutions for knowledge representation and reasoning problems using a systematic approach to exploring, understanding and extracting knowledge from data sources.
Working through Debellis (2021) Chapter 4 demonstrated Protégé development methodologies. The systematic approach to data exploration involves understanding data representation and meaningful structuring rather than simple data loading. Following Exercises 1-7 showed incremental development from basic classes to complex relationships, though the learning curve proved steeper than expected.
Data source understanding emerged as a prerequisite for effective ontology building. Issues around data quality, consistency, and completeness become apparent during knowledge formalization attempts. The systematic approach addresses these challenges, though without proper methodology, ontologies may inadequately represent their intended domains. The complexity of real-world data often exceeds theoretical frameworks.
This unit continues with tutorials to equip you with practical skills to develop knowledge-based systems. It explores inferencing and reasoning using Protégé software through worked examples from case studies.
The lecture cast covered logic-based representation and formal system complexity. Working with description logic (DL) demonstrated connections between McCarthy's AI formalization approach and current ontology development. Minsky's perspective highlighted the challenge of balancing flexibility with formal correctness, particularly since perfect completeness proves unattainable in real-world implementations.
Protégé reasoning tools provided concrete application of theoretical concepts. The Open World Assumption fundamentally alters the interpretation of "unknown" versus "false" information. Reasoning as inference from knowledge bases requires handling global and class consistency, emphasizing the necessity for precise definitions in logic systems and ontology-based rules, though this precision can limit practical flexibility.
This unit focuses on the architecture of a knowledge-based system and how various concepts fit within. It introduces further concepts to build on knowledge of reasoning in knowledge-based systems.
Working through Debellis (2021) exercises 22-26 demonstrated how reasoning transforms static ontologies into dynamic knowledge systems. The distinction between Open and Closed World Assumptions fundamentally alters possible conclusions. In medical systems like Bright et al.'s (2012) antibiotic prescribing ontology, OWA proves essential since missing data does not indicate false information, though this creates ambiguity in practical applications.
KBS architecture revealed interdependencies between knowledge base, inference engine, and user interface components. ALC and description logic complexity present challenges when balancing expressiveness with computational efficiency. The trade-off between complex reasoning capabilities and performance requirements remains difficult to optimize, particularly in resource-constrained environments.
This unit helps you reflect on various topics covered in the module and investigate the future of knowledge-based systems as an approach to developing AI systems. It identifies various projects and initiatives on ontology development for future KBS.
The lecture cast covered widespread adoption of ontology-based engineering across various sectors. Examples including ERP systems, manufacturing chains, and GIS applications demonstrate semantic technologies addressing practical business requirements beyond academic research contexts. The Ontology-Based Engineering Group's harmonization efforts address fragmentation across multiple domains attempting to implement these techniques.
Amirhosseini (2023) highlighted complexity issues in ontology evaluation for multi-domain systems. Challenges around UML to OWL conversion and consistency maintenance across different technological approaches present significant implementation barriers. Use cases like product design automation and dynamic manufacturing orchestration suggest potential applications, though scalability and integration challenges remain substantial obstacles for widespread adoption.
This unit focuses on end-to-end development of knowledge-based systems using ontology. It discusses approaches to ontology development, methodology, and evaluation approaches based on case studies.
De Colle et al.'s (2023) infectious disease ontology ecosystem demonstrated real-world ontology development complexity. Strategic choices from scope decisions to evaluation criteria indicate that successful ontology development requires project management and stakeholder engagement alongside technical modeling skills. The case study revealed gaps between theoretical frameworks and practical implementation challenges.
Reflective practice readings (Loughran, 2007; Bolton, 2006) emphasized learning through development process documentation. The module progression from basic KR concepts through practical Protégé implementation to industrial applications revealed incremental knowledge building, though connections between units sometimes felt forced. Ontology evaluation extends beyond technical correctness to problem-solving effectiveness, though measuring success remains subjective and context-dependent.