FAQ #

Each assignment will have an FAQ linked at the top. You can also access it by adding “/faq” to the end of the URL. The FAQ for Project 2B is located here.

Checkpoint Due 10/23/23 - Coding Due 10/30/23 #

In this project, you’ll complete your implementation of the NGordnet tool.

Unlike Project 2a, the implementation for this part of the project is very open-ended. Deciding on an overall design is an important skill that we’ll also revisit in Project 3. The number of lines of code for this project isn’t necessarily large, but there are a lot of independent decisions that you’ll need to make along the way.

Project Setup #

Skeleton Setup #

1. Similar to other assignments in this class, run git pull skeleton main to get the skeleton code for this project.
   1. NOTE: You’ll notice that this skeleton is (almost) the exact same as the Project 2A skeleton. We have provided placeholder implementations for TimeSeries, NGramMap from project 2a. This includes a working implementation of countHistory method using a new library from in library-fa23 (see next step).
   2. The placeholder implementations throw UnsupportedOperationExceptions for some methods. You will not need these methods.
2. To get the new library, cd into your library-fa23 directory and run git pull. Then, import all the libraries from library-fa23 into this project like you normally would.
   1. Now that you’ve pulled and imported the libraries, you’ll notice that the code in NgramMap.java should no longer be red.
3. Download the data files for this project using this link and move them into your proj2b folder on the same level as src.

Once you are done, your proj2b directory should look like this:

proj2b
├── data
│   ├── ngrams
│   └── wordnet
├── src
├── static
├── tests

Getting Started #

The course staff has created a couple of introductory videos to the project and the starter code available here.

We’ve also created two wonderful tools that you can (and should!) use to explore the dataset, see how the staff solution behaves for specific inputs, and get expected outputs for your unit tests (see Testing Your Code). We’ll link them here, as well as in other relevant parts of the spec.

• Wordnet Visualizer: Useful for visually understanding how synsets and hyponyms work and testing different words/lists of words for potential test case inputs. Click on the “?” bubbles to learn how to use the various features of this tool!
• Staff Solution Webpage: Useful for generating expected outputs for different test case inputs. Use this to write your unit tests!

Using the WordNet Dataset #

Before we can incorporate WordNet into our project, we first need to understand the WordNet dataset.

WordNet is a “semantic lexicon for the English language” that is used extensively by computational linguists and cognitive scientists; for example, it was a key component in IBM’s Watson. WordNet groups words into sets of synonyms called synsets and describes semantic relationships between them. One such relationship is the is-a relationship, which connects a hyponym (more specific synset) to a hypernym (more general synset). For example, “change” is a hypernym of “demotion”, since “demotion” is-a (type of) “change”. “change” is in turn a hyponym of “action”, since “change” is-a (type of) “action”. A visual depiction of some hyponym relationships in English is given below:

Each node in the graph above is a synset. Synsets consist of one or more words in English that all have the same meaning. For example, one synset is “jump, parachuting” , which represents the act of descending to the ground with a parachute. “jump, parachuting” is a hyponym of “descent”, since “jump, parachuting” is-a “descent”.

Words in English may belong to multiple synsets. This is just another way of saying words may have multiple meanings. For example, the word “jump” also belongs to the synset “jump, leap” , which represents the more figurative notion of jumping (e.g. a jump in attendance) rather the literal meaning of jump from the other synset (e.g. a jump over a puddle). The hypernym of the synset “jump, leap” is “increase”, since “jump, leap” is-an “increase”. Of course, there are other ways to “increase” something: for example, we can increase something through “augmentation,” and thus it is no surprise that we have an arrow pointing downwards from “increase” to “augmentation” in the diagram above.

Synsets may include not just words, but also what are known as collocations. You can think of these as single words that occur next to each other so often that they are considered a single word, e.g. nasal_decongestant . To avoid ambiguity, we will represent the constituent words of collocations as being separated with an underscore _ instead of the usual convention in English of separating them with spaces. For simplicity, we will refer to collocations as simply “words” throughout this document.

A synset may be a hyponym of multiple synsets. For example, “actifed” is a hyponym of both “antihistamine” and “ nasal_decongestant”, since “actifed” is both of these things.

Hyponyms (Basic Case) #

Setting up a HyponymsHandler #

1. In your web browser, open the ngordnet.html file in the static folder. As a refresher, you can find how to do that here. You’ll see that there is a new button: “ Hyponyms”. Note that there is also a new input box called k.

2. Try clicking the Hyponyms button. You’ll see nothing happens (and if you open the developer tools feature of your web browser, you’ll see that your browser shows an error).

In Project 2B, your primary task is to implement this button, which will require reading in a different type of dataset and synthesizing the results with the dataset from Project 2A. Unlike 2A, it will be entirely up to you to decide what classes you need to support this task.

1. Start by opening your ngordnet.main.Main.java file.
2. Create a new file called HyponymsHandler that simply returns the word “Hello!” when the user clicks the Hyponyms button in the browser. You’ll need to create a new HyponymsHandler class that extends the NgordnetQueryHandler class. See your other Handler classes for examples. Make sure when you register your handler that you use the string “hyponyms” as the first argument to the register method, and not “hyponym”.
3. Once you’ve modified Main so that your new handler is registered to handle hyponyms requests, start up Main and try clicking the Hyponyms button in your web browser again. You should see text appear that says “Hello”.

Hyponyms Handler (Basic Case) #

Next, you’ll create a partial implementation of the Hyponyms button. For now, this button should:

• Assume that the “words” entered is only a single word.
• Ignore startYear, endYear, and k.
• Return a string representation of a list of the hyponyms of the single word, including the word itself. The list should be in alphabetical order, with no repeated words.

For example, suppose the WordNet dataset looks like the diagram below (given to you as the input files synsets11.txt and hyponyms11.txt). Suppose that the user enters “descent” and clicks on the Hyponyms button.

In this case, the output of your handler should be the string representation of a list containing “descent”, “jump” and “ parachuting”, i.e [descent, jump, parachuting]. Note that the words are in alphabetical order.

As another example, suppose we’re using a bigger dataset such as the one below (given to you as the input files synsets16.txt and hyponyms16.txt):

Suppose the user enters “change” and clicks on the Hyponyms button. In this case, the hyponyms are all the words in the blue nodes in the diagram below:

That is the output is [alteration, change, demotion, increase, jump, leap, modification, saltation, transition, variation]. Note that even though “change” belongs to two different synsets, it only appears once.

Note: Don’t overthink this and make life harder than it needs to be. Specifically, observe that the output does not include:

• Synonyms of synonyms (e.g. does not include “adjustment”)
• Hyponyms of synonyms (e.g. does not include conversion)
• Hyponyms of other definitions of hyponyms (e.g. does not include "flashback", which is a hyponym of another definition of "transition")

Tips #

• Just like NGramMap, you’ll want your helper classes to only parse the input files once, in the constructor. DO NOT CREATE METHODS WHICH HAVE TO READ THE ENTIRE INPUT FILE EVERY TIME THEY ARE CALLED. This will be too slow!
• We strongly recommend creating at least two classes for this part of the project as follows: One which implements the idea of a directed graph. One which reads in the WordNet dataset and constructs an instance of the directed graph class. This second class should also be able to take a word and return its hyponyms. You may also want additional helper classes that represent the idea of a traversal but this is not required - you can implement your traversal within your graph class as well.
• Don’t worry about writing Truth tests yet, we’ll talk about how to do that later in the spec. Simply use the web front end to check the two input examples (“descent” and “change”) from the diagrams above for synsets16.txt and hyponyms16.txt.
• While you can (and should) write unit tests for the helper classes/methods that you create for this project, another good way to test and see what’s going on with your code is to simply run Main.java, open ngordnet.html, enter some inputs into the boxes, and click the “Hyponyms” button. You may find visual debugging can lead to some useful discoveries in this project.
• Because of the obfuscation that we applied to the Project 2a files (in particular, TimeSeries and NGramMap), the argument name previews when using these classes in IntelliJ may look a little weird. You may see long, random strings; these are intentional in order to obfuscate the code, and they do not represent an issue with your own code in any way.

WordNet File Format #

We now describe the two types of data files that store the WordNet dataset. These files are in comma separated format, meaning that each line contains a sequence of fields, separated by commas.

• File Type #1: List of noun synsets. The file synsets.txt (and other smaller files with synset in the name) lists all the synsets in WordNet. The first field is the synset id (an integer), the second field is the synonym set (or synset), and the third field is its dictionary definition. For example, the line

   6829,Goofy,a cartoon character created by Walt Disney
  

  means that the synset { Goofy } has an id number of 6829, and its definition is “a cartoon character created by Walt Disney”. The individual nouns that comprise a synset are separated by spaces (and a synset element is not permitted to contain a space). The S synset ids are numbered 0 through S − 1; the id numbers will appear consecutively in the synset file. The id numbers are useful because they also appear in the hyponym files, described as file type #2.

• File Type #2: List of hyponyms. The file hyponyms.txt (and other smaller files with hyponym in the name) contains the hyponym relationships: The first field is a synset id; subsequent fields are the id numbers of the synset’s direct hyponyms. For example, the following line

  79537,38611,9007
  

  means that the synset 79537 (“viceroy vicereine”) has two hyponyms: 38611 (“exarch”) and 9007 (“Khedive”), representing that exarchs and Khedives are both types of viceroys (or vicereine). The synsets are obtained from the corresponding lines in the file synsets.txt:

  79537,viceroy vicereine,governor of a country or province who rules...
  38611,exarch,a viceroy who governed a large province in the Roman Empire
  9007,Khedive,one of the Turkish viceroys who ruled Egypt between...
  

  There may be more than one line that starts with the same synset ID. For example, in hyponyms16.txt, we have

  11,12
  11,13
  

  This indicates that both synsets 12 and 13 are direct hyponyms of synset 11. These two could also have been combined on to one line, i.e. the line below would have the exact same meaning, namely that synsets 12 and 13 are direct hyponyms of synset 11.

  11,12,13
  

  You might ask why there are two ways of specifying the same thing. Real world data is often messy, and we have to deal with it.

Suggested Steps to Take #

To get the “Hyponyms” button working you’ll need to:

• Develop a graph class. If you aren’t familiar with this data structure, take a look at lectures 21 and 22. You should test this with operations that are independent of the given data files. For example, our tests evaluated that our createNode and addEdge functions yielded appropriate graphs by using our graph classes’s getNodes and neighbors functions. For inspiration, you can check out Lecture 21 and 22.
• Write code that converts the WordNet dataset files into a graph. This could be part of your graph class, or it could be a class that uses your graph class.
• Write code that takes a word, and uses a graph traversal to find all hyponyms of that word in the given graph.

We strongly recommended writing tests that evaluate queries on the examples above (for example, you might look at the hyponyms of “descent” in synsets11/hypernyms11, or the hyponyms of “change” in synsets16/hypernyms16).

Tests should be written at a level of abstraction appropriate to what they’re evaluating. For example, we have a class called TestGraph that evaluates various aspects of our Graph class.

Or as another example, our code has a class called TestWordNet containing the function below.

@Test
public void testHyponymsSimple(){
        WordNet wn=new WordNet("./data/wordnet/synsets11.txt","./data/wordnet/hyponyms11.txt");
        assertThat(wn.hyponyms("antihistamine")).isEqualTo(Set.of("antihistamine","actifed"))
        }

Note your WordNet class may not have the same functions as mine so the test shown will probably not work verbatim with your code. Note that our test does NOT use an NGramMap anywhere, nor is it using a HyponymHandler, nor is it directly invoking an object of type Graph. It is specifically tailored to testing the WordNet class. Relying on only browser tests will be incredibly frustrating (and slow!). Use your JUnit skills to build confidence in the foundational abstractions that you build (e.g. Graph, WordNet, etc.).

Design Tips #

This project involves having to do all sorts of different lookups, graph operations, and data processing operations. There is no one right way to do this.

Some example lookups that you might need to perform:

• Given a word (e.g. “change”), what nodes contain that word?
  • Example in synsets16.txt: change is in synsets 2 and 8
• Given an integer, what node goes with that index?
  • Necessary for processing hyponyms.txt. For example in hyponyms16.txt, we know that the node with synset 8 points at synsets 9 and 10, so we need to be able to find node 8 to get its adjacency list.
• Given a node, what words are in that node?
  • Example in synsets16.txt: synset 11 contains alteration, modification, and adjustment

Some example graph operations you might need to perform:

• Creating a node, e.g. each line of synsets16.txt contains the information for a node.
• Adding an edge to a node, e.g. each line of hyponyms16.txt contains one or more edges that should be added to the corresponding node.
• Finding reachable vertices, e.g. the vertices reachable from vertex #7 in hyponyms16.txt are 7, 8, 9, 10.

Your life will be a lot easier if you select instance variables for your classes that naturally help solve all six of the problems above.

Some example data processing operations:

• Given a collection of things, how do you find all non-duplicate items? (Hint: There is a data structure that makes this very easy and efficient). Don’t be afraid to also Google documentation for the data structure that you choose (e.g. if you choose to use a TreeMap for whatever reason, feel free to look up “TreeMap methods java”, “Map methods java”, or “Collection methods java”, etc).
• Given a collection of things, how do you sort them? (Hint: Google how to sort the collection that you’re using)

Handling Lists of Words #

Your next task is to handle lists of words. As an example, if the user enters “change, occurrence” for the diagram below, we should only return common hyponyms of each word, i.e. [alteration, change, increase, jump, leap, modification, saltation, transition]. “Demotion” and “variation” are not included because they are not hyponyms of both words; specifically, they are not hyponyms of “occurrence”.

As you can see, we only want to return words which are hyponyms of ALL words in the list. Furthermore, note that the list of words provided by the user can include more than just 2 words, even though our examples in this spec do not.

Note that it is possible for two words to share hyponyms without necessarily sharing nodes. Take a look at this example. If the user enters “car, bug” for the diagram below, we should get [beetle], not [] (empty list)! This example shows that we are getting the intersection of words, not nodes.

For some more examples which demonstrate the usefulness of this feature, let’s say we are using the full synsets.txt and hyponyms.txt.

• Entering “video, recording” in the words box and clicking “Hyponyms” should display [video, video_recording, videocassette, videotape], as these are all the words which are hyponyms of “video” and “recording”.
• Entering “pastry, tart” in the words box and then clicking “Hyponyms” should display [apple_tart, lobster_tart, quiche, quiche_Lorraine, tart, tartlet ].

Handling k != 0 #

Above, we handled the situation where k = 0, which is the default value when the user does not enter a k value.

Your final required task is to handle the case where the user enters k. k represents the maximum number of hyponyms that we want in our output. For example, if someone enters the word “dog”, and then enters k = 5, your code would return exactly 5 words.

To choose the 5 hyponyms, you should return the k words which occurred the most times in the time range requested. For example, if someone entered words = "food, cake", startYear = 1950, endYear = 1990, and k = 5, then you would find the 5 most popular words in that time period that are hyponyms of both food and cake. Here, the popularity is defined as the total number of times the word appears over the entire time period. The words should then be returned in alphabetical order. In this case, the answer is [biscuit, cake, kiss, snap, wafer] if we’re using top_49887_words.csv, synsets.txt, and hyponyms.txt.

Note that if the front end doesn’t supply a year, default values of startYear = 1900 and endYear = 2020 are provided by NGordnetQueryHandler.readQueryMap.

If k = 0, or the user does not enter k (which results in a default value of zero), then the startYear and endYear should be totally ignored.

If a word never occurs in the time frame specified, i.e. the count is zero, it should not be returned. In other words, if k > 0, we should not show any words that do not appear in the ngrams dataset.

If there are no words that have non-zero counts, you should return an empty list, i.e. [].

If there are fewer than k words with non-zero counts, return only those words. For example if you enter the word “potato” and enter “k = 15”, but only 7 hyponyms of potato have non-zero counts, you’d return only 7 words.

Tips #

• Until you use the autograder, you’ll need to construct your own test cases. We provide one above: words = "food, cake" , startYear = 1950, endYear = 1990, k = 5.
• When constructing your own test cases, consider making your own input files. Using the large input files we provide is extremely tedious.
• In the coming sections of this spec, we’ll tell you how to set up your code for submission to the autograder, and how to write your own JUnit tests to mimic the test cases provided by the grader.

Deliverables and Scoring #

For Project 2B, the only required deliverable is the HyponymsHandler.java file, in addition to any helper classes. However, we will not be directly grading these classes, since they can vary from student to student.

Project 2B will be worth 75 points. The points will be split as follows:

• Checkpoint (5 points - Due October 23th)
• Coding (70 points - Due October 30th):
  • HyponymHandler single word case: 40%, k = 0
  • HyponymHandler multi-word case: 20%, k = 0
  • HyponymHandler popularity: 40%, k != 0

The token limiting policy for this project will be as follows:

1. You will start with 8 tokens, each of which has a 24-hour refresh time.
2. At 10:00 PM on October 30th (2 hours before the deadline), you will be reset to 4 tokens, each of which has a 15-minute refresh time.
3. At 12:00AM on October 31st, you will again be reset back to 8 tokens with a 24-hour refresh.

Testing Your Code #

We’ve provided you with two short unit test files for this project in the proj2b_testing directory:

• proj2b_testing/TestOneWordK0Hyponyms.java
• proj2b_testing/TestMultiWordK0Hyponyms.java

The two provided test files correspond to the first two cases that you solved in this project, that is:

• Finding hyponyms of a single word where k = 0.
• Finding hyponyms of multiple words where k = 0 (e.g. gallery, bowl).

These test files are not comprehensive; in fact, they each only contain one sanity check test. You should fill each file with more unit tests, and also use them as a template to create two new test files for the respective cases where k != 0.

Debugging Tips #

• Use the small files while testing! This decreases the startup time to run Main.java and makes it easier to reason about the code. If you’re running Main.java, these files are set in the first few lines of the main method. For unit tests, the file names are passed into the getHyponymHandler method.
• You can run Main.java with the debugger to debug different inputs quickly. After clicking the “Hyponyms” button, your code will execute with the debugger - breakpoints will be triggered, you can use the variables window, etc.
• There are a lot of moving parts to this project. Don’t start by debugging line-by-line. Instead, narrow down which function/region of your code is not working correctly then search more closely in those lines.
• Check the FAQ for common issues and questions.

Submitting Your Code #

Throughout this assignment, we’ve had you use your front end to test your code. Our grader is not sophisticated enough to pretend to be a web browser and call your code. Instead, we’ll need you to provide a method in the proj2b_testing.AutograderBuddy class that provides a handler that can deal with hyponyms requests.

When you ran git pull skeleton main at the start of this spec, you should have received a file called AutograderBuddy.java

Open AutograderBuddy.java and fill in the getHyponymHandler method such that it returns a HyponymsHandler that uses the four given files. Your code here should be quite similar to your code in Main.java.

Now that you’ve created proj2b_testing.AutograderBuddy, you can submit to the autograder. If you fail any tests, you should be able to replicate them locally as JUnit tests by building on the test files above. If any additional datafiles are needed, they will be added to this section as links.

Optional Extra Features #

If you’d like to go above and beyond in this project (and even explore some front-end development), read through the Optional Features spec!

Acknowledgements #

The WordNet part of this assignment is loosely adapted from Alina Ene and Kevin Wayne’s Wordnet assignment at Princeton University.