A6. Ontology

Assigned: 
October 12, 2011
Due: 
October 17, 2011 - 09:00
Create a new Assignment Submission Page titled: "A6 - Your Name".  

In this assignment, you will:
  1. Define equivalence classes for 15 animal instances.
  2. Sort those classes into a hierarchy of animal types.
  3. Create a diagram of your ontology.
  4. Write definitions for each part of your ontology using hypernyms and hyponyms. 
  5. Reflect on your experience.

Submission Requirements
You will submit a zip file named YourNameA6.zip that includes 3 files: 1. A spreadsheet (modeled on the sample spreadsheet attached here) called YourNameA6.xls; 2. Your diagram, which will be called YourNameA6.pdf; and 3. A brief reflection (YourNameA6Reflection, in pdf or doc format). Regardless of what method you use to make your diagram, please save a copy as a pdf so we can be sure we’re seeing what you intended for us to see.

Detailed Instructions
In this assignment, you’ll be returning to your “ark” from A5: the set of 10 original animal instances plus whichever bonus set you selected. This time, you’ll be developing a hierarchical classification scheme. The goal of this assignment is to give you more practice thinking about categories and category membership, abstraction, classification, and ontology.



Part 1: Identify your types/equivalence classes

Round up your animals by returning to your 15 instances from A5. In a spreadsheet, following the format of the attached sample, create a list of these animals. (Hint: Remember that each of the instances came with a name attached for A5 and you should continue using these names).

For each animal instance, identify a “type” or equivalence class to which that instance belongs. For example, if we were classifying musical instruments, and you’d been given a picture of a drum set, you might pick something like “rhythm instrument” as the type. Or you might choose something more granular or more abstract than that — remember, as always, you’re making a choice about the level of abstraction you use.

As you’re making your first pass through the instances, do not stress out too much about naming these types. You’re likely to go back to them and revise them as you progress through the assignment. If it’s starting to make you feel crazy, our advice is to come up with something temporary and move on; new ideas might pop up once you’ve started to arrange your hierarchy. 


Part 2. Organize your types into a hierarchy

Now that you’ve taken a crack at identifying types for each of your animals, begin arranging them into a hierarchy. The top or root element of your hierarchy will be “animals.” The bottom level of your hierarchy will be your instances. When you created your types in Part 1, you added a second level to the hierarchy — more abstract than your instances but less abstract than “animals.” What you’re doing now is adding one more level of abstraction — a new level between your types and “animal.” These are hypernyms or "super-types."

At this phase of the assignment, it’s important that you strive for a consistent level of abstraction among your “super-types” (hypernyms). For example, with musical instruments as our root, if our next level down included both “clarinets” and “stringed instruments” that might be a sign that the classification wasn’t maintaining a consistent level of abstraction.


Part 3: Create a diagram or visualization of your hierarchy.

This does not have to be fancy. We repeat: This does not have to be fancy. Start with “animal” at the top or root of your visualization, then your “super-types,” then your types. You can use any tool you wish (including drawing by hand and scanning your drawing), as long as it allows you to represent the hierarchical relations in your ontology. 


Part 4: Define your types and “super-types.”

Now, you’re going to write a definition for your equivalence classes and your “super-types” such that an ordinary person would be able to categorize new instances. You’ll be following this formula for definitions:

Hyponym = {adjective+} hypernym {distinguishing clause}

Example: Clarinets = {reeded} Woodwinds {that are approximately cylindrical in shape and have numerous keys}

Woodwinds = {reed or flute} Instruments {that produce sound when air is blown into them}

Record each definition in your spreadsheet.


Part 5: Reflect on your experience

In your YourNameA6Reflection document, write a few paragraphs about the approaches you used to identify equivalence classes and organize them into “super-types.” Consider your thought process throughout the assignment, tips from readings or lectures you drew on, finding consistency in your layers of abstraction, and whether this was easier or harder than A5 for you.