Foundations of the Semantic Web: Ontology Engineering Lab 2: Untangling Ontologies Open World Reasoning Alan Rector & colleagues SETUP: Download Teaching-4-01-people-tangled.daml existentials-and-universals.daml from www.cs.man.ac.uk/~rector/CS646 Get the supplementary handout Existentials & Universals

Normalise the person hierarchy starting from Teaching-4-01-people-tangled.daml Create the necessary properties, roles, and value types to separate sex, academic rank, age group, ethnicity There should be a separate functional property for each There should be a separate ValueType for each The values under the value type should be disjoint Each kind of Person should be defined Define a student as a Person who attends an Academic_institution Classify and check the classification is correct When you are satisfied with the classification, Define a set of probe classes to test if the appropriate kinds of people are disjoint or not.

Add additional information A Subclass axiom to say that “All academic staff are adults” A new kind of Teaching_activity called Seminar Define a “Professorial seminar” as a Seminar given by a Professor Define an “Assisted professorial seminar” as a seminar given by a professor and at least one other member of academic staff

Add rules about professorial seminars Add a new property enrolled_in and define an “ACS student” as a student enrolled in the ACS_course Should enrolled in be functional? Why or why not? Add an axiom to say that all “ACS students” must take a “Professorial seminar” Define a “Student taking a professorial seminar” Classify? Is the classification correct? Define a probe to check if a violation of the axiom causes an inconsistency

If you have not done so already, download existentials-and-universals If you have not done so already, download existentials-and-universals.daml Work through the exercises on the separate sheet Be sure you understand how to fix the problem

Equivalence Another way to check understanding When preparing to change a class, it is often useful to create a one or more trial subclasses and clasify the result. If you think two different definitions should be equivalent, they should come out equivalent when classified, consider… Define two different subclasses of third year module Third_year_module_try_1 complete Third_year_module and restriction (includes allValuesFrom (Lecture or Exam)) Third_year_module_try_2 complete Third_year_module and not (restriction includes someValuesFrom Lab) Refer to the explanation on slides 79-82 in Handout 1 to modify the rest of the KB so that the two definitions are equivalent as shown in slide 81.

Prepare the Module hierarchy for normalisation Define a class ACS_course, Third_year_course, and CS_course Change the definition of ACS_module and Third_year module to be that they belong_to the ACS_course, Third_year_course, etc. Define Test_Module = Module and restriction belongs-to someValuesFrom ACS_course Classify it. Does it come out as equal to ACS_module? If not why not? Refer to Separate handout on “Definitions, Descriptions, Restrictions & Axioms”

Domain and Range Constraints Add appropriate domain and range constraints to all properties Have you made anything unsatisfiable? Have you made any changes in the hierarchy Should you have?