Description
This assignment contains two parts. First, you will implement a Model-based
Collaborating Filtering(CF) recommendation system using Spark MLlib. Second, you will implement either a User-based CF system or Item-based CF system
without using a library. The dataset you are going to use are the Yelp challenge
dataset. The task sections below will explain the assignment instructions in detail. The goal of the assignment is to make you understand how different types
of recommendation systems work and more importantly, try to find a way to
improve the accuracy of the recommendation system yourself.
Environment Requirements
Python: 2.7 Scala: 2.11 Spark: 2.3.1
Student can use Python or Scala to complete both Task1 and Task2.
There will be 10% bonus if you use Scala for both Task1 and Task2 (i.e. 10
– 11; 9 – 10).
IMPORTANT: We will use these versions to compile and test your code. If
you use other versions, there will be a 20% penalty since we will not be able to
grade it automatically.
You can only use Spark RDD.
In order for you to understand more deeply of the Spark, use RDD
only, you won’t get any point if you use Dataframe or Dataset.
Write your own code!
For this assignment to be an effective learning experience, you must write your
own code! I emphasize this point because you will be able to find Python
implementations of most or perhaps even all of the required functions on the
web. Please do not look for or at any such code!
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TA will combine some python code on Github which can be searched by keyword ”INF553” and every students’ code, using some software tool for detecting
Plagiarism.
Do not share code with other students in the class!!
Submission Details
For this assignment you will need to turn in a Python or Scala program depending on your language of preference. This assignment will surely need some time
to be implemented so please plan accordingly and start early!
Your submission must be a .zip file with name: Firstname Lastname hw2.zip.
The structure of your submission should be identical as shown below.
The Firstname Lastname Description.pdf file contains helpful instructions
on how to run your code along with other necessary information as described
in the following sections.
The OutputFiles directory contains the deliverable output files for each problem and the Solution directory contains your source code.
Figure 1: Submission Structure
Data
In this assignment, we will use the yelp challenge dataset, the ”yelp challenge
dataset” can be download from this link: Yelp Challenge. In order to download
the dataset, you need to use your email to sign up individually in the Yelp
challenge website. Detailed introduction of the data can also be found through
the link, in the document tab. After download and unzip the data, the dataset
contain 6 .json file and two .pdf file. In this assignment, the reviews.json file
and three columns in the review file will be used: user id, business id, stars.
The yelp dataset contains more than 6 million review record between millons of the user and business. Because the huge volume and the sparseness
between the user and business, the recommendation system will take a lot of
computation, we extract the subset of the whole dataset so that the assignment
can end on a reasonable time for every students’ laptop. In order to finish this
assignment, you only need the two data file in the Data/ folder.
We recommend you download the whole dataset as the playground of the
data mining or any other area.
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Yelp Dataset Description
yelp academic dataset business.json : 188,593 records
Attributes: Business ID, address, name, city, Business hours, Categories,
rating and reviews count
yelp academic dataset review.json : 5,996,996 records
Attributes: review ID, user ID, business ID, rating, comments
yelp academic dataset user.json : 1,518,169 records
Attributes: user ID, name, review count, Yelp join date
yelp academic dataset checkin.json : 157,075 records
Attributes: Business ID, time
yelp academic dataset tip.json : 1,185,348 records
Attributes: user ID, Business ID, text, likes, date
yelp academic dataset photo.json : 280,992 records
Attributes: photo ID, Business ID, text
Dataset for Assignment
In this assignment, we extract the subset of the whole dataset contains 452353
reviews between 30,000 user and 30,000 business and split them to train data
(90%) and test data (10%). you can get two files in the Data/: train review.csv
and test review.csv, each file contain three conlumns: user id, business id, and
stars. And we will use these two files to finish and test our recommendation
system.
Task of Recomendation System
The task of this the recommendation system is to use the records in the train.csv
to predict the stars for users and businesses in the test.csv. Then, you need
to use the stars in testing data as the ground truth to evaluate the accuracy of
your recommendation system.
Example: Assuming train.csv contains 1 million records and the test.csv contains two records: (12345, 2, 3) and (12345, 13, 4). You will use the records
in the train.csv to train a recommendation system (1 million). Finally, given
the user id 12345 and business id 2 and 13, your system should produce rating
predictions as close as 3 and 4, respectively.
2 Task1: Model-based CF Algorithms (30 Points)
In task1, you are required to implement a Model-based CF recommendation
system by using Spark MLlib. You can learn more about Spark MLlib by this
link: MLlib
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You are going to predict the testing datasets mentioned above. In your
code, you can set the parameters yourself to reach a better performance. You
can make any improvement to your recommendation system: speed, accuracy.
After achieving the prediction for ratings, you need to compare your result
to the correspond ground truth and compute the absolute differences. You
need to divide the absolute differences into 5 levels and count the number of
your prediction for each level as following:
>=0 and <1: 12345 (there are 12345 predictions with a < 1 difference from the ground truth) >=1 and <2: 123 >=2 and <3: 1234 >=3 and <4: 1234 >=4: 12
Additionally, you need to compute the RMSE (Root Mean Squared Error)
by using following formula:
RMSE =
r
1
n
X(P redi − Ratei)
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Where P redi
is the prediction stars for business i, Ratei
is the true stars
for business i, n is the total number of the review. Read the Microsoft paper
mentioned in class to know more about how to use RMSE for evaluating your
recommendation system.
Tips: For model-based CF, you may need to index the user id and business id
to integer.
BaseLine
After implementing the model-based CF, you can try to change the parameters
of the model and see the change of the RMSE of the recommendation. You need
to find the parameters that can beat the baseline to get the full grade.
Here is the baseline of the Model-Based CF:
RMSE = 1.08
3 User-based or Item-based CF Algorithm (70
Points)
In this part, you are required to implement a User-based CF or Item-based
recommendation system with Spark. For the detail of the User-Based CF and
the Item-Based CF, you can find it from the slides of the lecture or from many
tutorial from the Internet.
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You are going to predict for the testing datasets mentioned above. Based
on the User-based or Item-based CF, you can make any improvement to your
recommendation system: speed, accuracy (e.g., Hybird approaches). It’s your
time to design the recommendation system yourself, but first you need to beat
the baseline.
After achieving the prediction for ratings, you need to compute the accuracy
in the same way mentioned in Model-based CF.
Result Format
1. Save the predication results in a text file. The result is ordered by user id
and business Id in ascending order.
Example Format:
user1, business2, prediction12
user1, business3, prediction13
. . .
usern, businessk, predictionnk
2. Print the accuracy information in terminal, and copy this value in
your description file.
>=0 and <1: 12345 >=1 and <2: 123 >=2 and <3: 1234 >=3 and <4: 1234 >=4: 12
RMSE: 1.23456789
Time: 123 sec
Baseline & Time Threshold
Same as the Model-Based CF, in order to get the full point of the grade, you
need to beat the baseline first. And this task has the time threshold, make sure
that your program can give the result within a reasonable time.
You can use any method (based on user-based or item-based CF) to improve
the performance of your recommendation system, for example, you can find
someway to refine the result from the User-Based or Item-Based CF, or combine
the result from User-Based and Item-Based CF.
RMSE = 1.11
T ime T hreshold : 450 Second
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Execution Example
The first argument passed to our program (in the below execution) is the training
csv file. The second input is the testing csv file. Following we present examples
of how you can run your program with spark-submit both when your application
is a Java/Scala program or a Python script.
Example of running application with spark-submit
Notice that the argument class of the spark-submit specifies the main class
of your application and it is followed by the jar file of the application.
Please use ModelBasedCF, UserBasedCF, ItemBasedCF as class name
Figure 2: CF: Command Line Format for Scala
Figure 3: CF: Command Line Format for python
You don’t need to specify the path of the output file in the commandline, you
only need to save the file with the name format Firstname Lastname XXXXBasedCF.txt.
in the same path your program run (Relative Path).
Description File
Please include the following content in your description file:
1. Mention the Spark version and Python version
2. Describe how to run your program for both tasks
3. Same baseline table as mentioned in task 1 to record your accuracy and
run time of programs in task 2
4. If you make any improvement in your recommendation system, please
also describe it in your description file.
Submission Details
Your submission must be a .zip file with name: Firstname Lastname hw2.zip
Please include all the files in the right directory as following:
1. A description file: Firstname Lastname desription.pdf
2. All Scala scripts:
Firstname Lastname ModelBasedCF.scala
Firstname Lastname UserBasedCF.scala
Firstname Lastname ItemBasedCF.scala
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3. A jar package for all Scala file: Firstname Lastname hw2.jar
If you use Scala, please make all *.scala file into ONLY ONE
Firstname Lastname hw2.jar file and strictly follow the class name mentioned
above. And DO NOT include any data or unrelated libraries into your jar.
4. If you use Python, then all python scripts:
Firstname Lastname ModelBasedCF.py
Firstname Lastname UserBasedCF.py
Firstname Lastname ItemBasedCF.py
5. Required result files for task1 & 2:
Firstname Lastname ModelBasedCF.txt
Firstname Lastname UserBasedCF.txt
Firstname Lastname ItemBasedCF.txt
Grading Criteria
1. If your programs cannot be run with the commands you provide, your
submission will be graded based on the result files you submit and 80%
penalty for it.
2. If the files generated by your programs are not sorted based on the
specifications, there will be 20% penalty.
3. If your program generates more than one file, there will be 20% penalty.
4. If you don’t provide the source code and just the .jar file in case of a
Java/Scala application there will be 80% penalty.
5. If the running time or RMSE is greater than the base line, there’ll be 20%
penalty for each part as mentioned above.
6. If your prediction result files miss any records, there will be 30% penalty
7. There will be 20% penalty for late submission within a week and 0 grade
after a week.
8. You can use your free 5-day extension.
9. There will be 10% bonus if you use both Scala for the entire assignment.
10. There will 0 grade if you use Dataframe or Dataset.
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