Due: October 24, 2013, 9 a.m.
The goal of this assignment is to give you practice thinking about categorization and category membership, abstraction, classification, and ontologies. Pretend you are a prehistoric human, just starting to think about abstract concepts. You come across 15 animals, and decide to organize them into a hierarchical classification scheme, using properties and behaviors you can directly observe. (We are setting the stage this way to emphasize that we want you to create an intuitive classification and not a scientific one. We do not want to you consult authoritative biological classifications. Please don’t fret about the impossibility that a prehistoric human might encounter all 15 of these animals).
In this assignment, you will:
- Define equivalence classes for 15 animal instances
- Sort those classes into a hierarchy of animal types
- Create a diagram of your ontology
- Write definitions for each part of your ontology using hypernyms and hyponyms
- Reflect on your experience.
Submission Requirements
You will submit a zip file named FirstnameLastnameA6.zip that includes 3 files:
- A spreadsheet (modeled on the sample spreadsheet attached here) called FirstnameLastnameA6.pdf
- Your diagram, which will be called FirstnameLastnameA6.pdf
- A brief reflection (FirstnameLastnameA6Reflection, in pdf format)
Regardless of what method you use to make your diagram, please submit all of your files as a pdf so we can be sure we’re seeing what you intended for us to see.
Part 1: Identify Equivalence Classes (3 points)
Remember that an equivalence class, also known as category or type, is a way of specifying that a group of resources should be considered the same thing in a given context. With that in mind, look at the 15 animals here: https://www.dropbox.com/sh/bdopy1ntiuzgjiy/6Km8_T8Sah
Using this attached spreadsheet, list the 15 animals using the animal name listed on each file (i.e., Fish, Penguin, Eagle, …).
For each animal instance, identify a possible equivalence class to which the instance belongs. For example, if we were classifying musical instruments, and you were creating an equivalence class for a drum set, you might pick something like “rhythm instrument”. Depending on the other musical instruments you were organizing, you might want a more abstract (instruments) or less abstract (four piece drum sets) equivalence class. You are making a choice about the level of abstraction you use.
As you are making your first pass through the instances, do not worry too much about naming these types. Organizing is an iterative process. You are likely to go back to them and revise them as you progress through the assignment. If the ambiguity is making you a little crazy, our advice is to come up with a placeholder and move on; new naming ideas might surface as you start to arrange your hierarchy.
Focus on what is observable from the image, and not from further research. You may use what you already know about the behavior of the different animals as long as it is something that can be observed (e.g. birds fly, fish swim, giraffes walk).
Part 2. Organize Your Equivalence Classes into a Hierarchy (2 points)
Now that you have identified equivalence classes for each of the animal instances, begin arranging the classes into a hierarchy. The root element of your hierarchy will be “Animals.” The leaf level elements of your hierarchy will be the specific animal instances. When you created your equivalence classes in Part 1, you added a second level to the hierarchy — more abstract than your instances but less abstract than “Animals.” Take this one step further by adding one more level of abstraction — a new level between your equivalence classes 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, if “musical instruments” was our root and the next level down included the groupings “clarinets” and “stringed instruments” that might be a sign that our classification system did not maintain a consistent level of abstraction.
Part 3: Create a Diagram or Visualization of Your Hierarchy (1 point)
The visualization does not have to be fancy. We repeat: it does not have to be fancy. Start with “Animal” as the root of your hierarchy, then add your “super-types,” then add your types, and then your animal instances as the final level in your diagram. 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” (2 points)
Now, you will write definitions for both your equivalence classes and your ‘super types’ so 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 (2 points)
In your reflection 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.
Download: Assignment 6 Starter Spreadsheet