Two "Thread" classes in observable namespace should disambiguate

[ajnelson-nist]

Background

The Observable namespace defines two classes with the word "Thread" in their name:

• observable:MessageThread
• observable:Thread

These classes are unrelated to one another. MessageThread pertains to reply chains of messages. Thread pertains to processes.

Another proposal is considering creating a class in the UCO Types namespace, Thread, to define a class similar to, but disjoint from, the Collections Ontology's co:List. The co:List is an ordered list, but totally ordered - it is strictly linear, and cannot fork. The types:Thread class under consideration presents linked-list qualities of co:List, but permits forking.

While defining types:Thread, the class observable:Thread came up while reviewing concept basenames (i.e. the names after namesapce prefixes) for uniqueness across UCO.

For the sake of the types:Thread class (which is under proposal), and for the sake of focusing observable:Thread to processes, it would benefit UCO to rename observable:Thread to reflect its scope.

Requirements

Requirement 1

observable:Thread should be renamed to prevent confusion with other concepts that include Thread in their basename.

Risk / Benefit analysis

Benefits

• An incorrect substring-based association between observable:MessageThread and observable:ProcessThread is removed.

Risks

• Towards the proposal to add types:Thread - the rename in this proposal admittedly shifts the substring-based association error to now confusing types:Thread and observable:ProcessThread. There is some relief in observable:ProcessThread generally not being mistaken as a list itself (though it certainly is frequently understood as a linked-list member).
• A concept name change is a backwards-compatibility issue for current users of the observable:Thread class.

Competencies demonstrated

Competency 1

There are some classes in UCO that include the word "Thread".

Competency Question 1.1

How do they relate?

Result 1.1

In the current state of UCO (plus the other proposal), here is how classes fitting the pattern *Thread* relate to one another:

observable:MessageThread rdfs:subClassOf observable:ObservableObject .

observable:MessageThread rdfs:subClassOf types:Thread .  # (under proposal)

observable:MessageThreadFacet rdfs:subClassOf core:Facet .

observable:Thread rdfs:subClassOf observable:ObservableObject .

observable:WindowsThread rdfs:subClassOf rdfs:subClassOf observable:Thread .

observable:WindowsThreadFacet rdfs:subClassOf core:Facet .

Solution suggestion

• Rename observable:Thread to observable:ProcessThread.
• (There is no observable:ThreadFacet to rename.)

Coordination

• Tracking in Jira ticket OC-241
• [x] Administrative review completed, proposal announced to Ontology Committees (OCs) on 2022-05-26
• [x] Requirements to be discussed in OC meeting, 2022-06-02
• [x] Requirements Review vote occurred, passing, on 2022-06-13
• [x] Requirements development phase completed.
• [x] Solution announced to OCs on 2022-06-22
• [x] Solutions Approval to be discussed in OC meeting, 2022-06-30
• [x] Solutions Approval vote occurred, passing, on 2022-06-30
• [x] Solutions development phase completed.
• [x] Implementation merged into develop
• [x] Milestone linked
• [x] Documentation logged in pending release page

[ajnelson-nist]

A committee member noticed that we have a typo, MessageTread.

[ajnelson-nist]

PR 392 has passed its review checklist.