Questions tagged [recommender-system]

Everything related to recommender systems

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1answer
13 views

How does recommendation by matrix factorization deal with new movies / users?

Assume you have the ratings of $n$ users for $m$ movies in a matrix $R \in \mathbb{R}^{n \times m}$. You compute a representation $$R = U \times \Sigma \times V$$ by initializing $u_i, v_j \forall i ...
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0answers
6 views

Recommender with global explicit feedback

I've to build a recommendation system with a dataset where the feedback is given for the whole set of items instead to the specific items. We can see that feedback as a numerical indicator of the ...
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1answer
9 views

Document matching with more priority to certain features than others

I am working on recommendation systems wherein I need to match the similarity of 2 users. Now, I know that I can use Tfidf vectorizer to calculate the the cosine similarity score between them. But, ...
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12 views

Handling collection of featurevectors for classification

I have a data set where devices are represented by a collection of variables. These variables consist of several properties like a name, datatype, driver, limit values, etc. (mixed data; quantitative ...
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6answers
131 views

Distance between users

I want to compute the "distance" between users in order to return the top n similar users, for any given user. For each user a have a bunch of features. This is close to a recommendation system, ...
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0answers
16 views

Recommender with global feedback [closed]

I've to build a recommendation system with a dataset where the feedback is given for the whole set of items instead to the specific items. We can see that feedback as a numerical indicator of the ...
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0answers
6 views

Building a dynamic recommender system that changes based on how users rate

I am trying to build a recommender system for coding interview questions. I thought of doing a collaborative-filtering, but it is hard to get data on how other users rated the questions. I currently ...
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1answer
25 views

Recommender systems and Machine Learning

According to Mitchell: “A computer program is said to learn from experience E with respect to some class of tasks T and performance measure P, if its performance at tasks in T , as measured by P , ...
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13 views

Building a personalized recommender system for coding interview questions?

I am trying to build a recommender system for coding interview questions. Let's say I have data for interview questions and the features are ...
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6 views

Any library recommendations for a Python recommender framework with multi-class input, incl. array input?

(crosspost from https://softwarerecs.stackexchange.com/questions/62491/python-recommender-framework-with-array-input, this meta post seems to justify doing this. I really really need answers to this, ...
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0answers
16 views

How can you recommend songs based on a user's past listening history by genre (content filtering)?

I'm interested in getting a user's past listening history from Spotify (API call to recently played) and being able to suggest songs from the Charts (another API call for current chat listings) that a ...
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0answers
16 views

Building recommendation engine from transactions data

I am trying to build a recommendation engine for an e-commerce company and I have the following input files : 1) past user transactions + in-app events 2) a new list of campaigns I should recommend ...
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0answers
7 views

How to reduce complexity of inference stage in recommender systems?

Given a large set of customers and a large set of items, how to make predictions given a model like this one: https://arxiv.org/pdf/1606.07792.pdf As stated in the article: "Since there are over a ...
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1answer
57 views

Use machine learning to predict next schedule meeting for sales officers

I have a project with data of sales field officers who visit their customers and enter the progress details. Visit can be an order or any kind of customer interaction. Let's say one sales guy has ...
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0answers
11 views

We know the subspace generated from the data instances, but we cannot constitute the origin space

I was wondering, what if we know the subspace generated F from the data instances, but we cannot constitute the origin space E that can be in higher dimension, and can easily lead us to the true join ...
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1answer
32 views

Calculate a ranking function from classification features

I am using 3 features (x1, x2, x3) for binary classification. All my feature values are in 0 to 1 range (unit range). I obtained how important each feature was in ...
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1answer
36 views

How to use testing data set to measure recommender system algorithm

I am new to recommender systems and am trying to build one using item-to-time CF. Currently, I am trying to evaluate/measure results using MAE. I have one step which is unclear (after I managed to ...
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0answers
12 views

What is the accepted level of persona coverage for Recommender Systems?

Almost all of e-commerce companies use recommender systems which involve a set of personas. (explained in this post). "Your personas will never cover 100% of your users" In practice, what is the ...
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0answers
13 views

scala spark FP-Growth no results displayed

I have implemented the FP-growth algorithm and it works fine with this sample data: r z h k p z y x w v u t s s x o n r x z y m t s q e z x z y r q t p when I ...
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0answers
14 views

I got a overall mean average precision score of 0 for a recommendation engine

I just wanted to know if receiving an overall MAP score of 0 in a recommendation engine was possible, or a sign that my calculation or my logic for the engine was wrong.
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0answers
67 views

Cosine similarity with arrays contaning NaN

I am trying to calculate a cosine similarity using Python in order to find similar users basing on ratings they have given to movies. As it can be expected there are a lot of NaN values. I am using ...
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1answer
21 views

How many time a recommender system can recommand the same item to an user?

I'm working on an hybrid music recommender system project, my goal is to create recommendation playlists in accordance with users tastes. I already implemented the first part which use a collaborative ...
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0answers
17 views

Personalised search ranking for hotels

I've built hotel embeddings which gives very satisfactory results in returning similar hotels for each hotel. Now the problem I'm trying to solve is to rank the hotels in order of relevancy to the ...
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0answers
37 views

Is it a good idea to train Neural Network for classification on dataset where each document has a different class i.e. no class is repeated again?

My goal is to build a recommendation model for which I want to use Neural Network (LSTM). The user will give some input keywords and the model should return the suggestions (classes) based on ...
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1answer
25 views

How to validate recommender model in healthcare?

In order to validate a recommender model, a usual approach is create a hold-out set that will provide random suggestions (similar to an A/B testing setup). However, in healthcare applications, this ...
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0answers
19 views

How do I recommend items to out of training users based on its recent views?

I used Spark's ALS implementation of matrix factorization (Collaborative Filtering for Implicit Feedback) to train user and item embeddings. Since we have a lot of users in system, I had to sample ...
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1answer
28 views

What is the range of values of the expected percentile ranking?

I'm currently reading Hu, Koren, Volinsky: Collaborative Filtering for Implicit Feedback Datasets One thing that confuses me is the "expected percentile ranking", an function the authors define to ...
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27 views

Understanding Youtube recommender (candidate generation step)

I'm trying to understand https://storage.googleapis.com/pub-tools-public-publication-data/pdf/45530.pdf Their candidate generation step outputs topn items via softmax (with negative sampling) at ...
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1answer
43 views

A weird result from a recommender system

Say there're the top 10 most popular items among 100 sales products and about 100k users regularly purchase items on daily basis. ...
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0answers
24 views

Mining Association rules from a data warehouse and a transactional database [closed]

I wonder if it is possible to perform market basket analysis to extract the association rules from a data warehouse and a transactional database in the same time to predict the future purchases of a ...
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2answers
28 views

How do I correctly build model on given data to predict target parameter?

I have some dataset which contains different paramteres and data.head() looks like this Applied some preprocessing and performed Feature ranking - ...
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2answers
1k views

Do recommendation systems necessarily use machine learning algorithms?

I am studying about evaluation of both recommendation systems and machine learning algorithms in recent times, trying to define a scope for my masters research. After some reading time I'm starting to ...
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1answer
29 views

Null predictions for ALS in Pyspark

I am trying to read from my dataset which has three coloumns. (User, Repository and Number of Stars) In[10] ...
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0answers
24 views

Can transfer learning be applied to predict sales

Let matrix A be a user item matrix.Upon performing UV decomposition , I get a user factor matrix and factor entity matrix. The company I am interning at doesn't keep track of the user factor matrix.I ...
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5 views

Does cardinality of ratings column affect performance of matrix factorization based collaborative filtering?

I am using mllib's implicit preference based implementation of collaborative filtering for generating grocery product recommendations in e-commerce, based on this Netflix Prize winning algorithm. I ...
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31 views

How to training the recurrent recommender system with LSTM?

Recently, I read a paper about recurrent recommender system, I am very curious about how it training its network. Assume I have the Netflix dataset as ...
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0answers
19 views

recommend new category paths based on factor item matrix and sales of the items

Matrix A be a user item matrix. Upon performing UV decomposition, I have just the V matrix. The matrix A differs every week and I get a new V matrix every week. The matrix U is not kept track of and ...
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0answers
33 views

Learning similarity of representations

I am interested in a framework for learning the similarity of different input representations based on some common context. I have looked into word2vec, SVD and other recommender systems, which does ...
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4answers
64 views

How to match a user with another user based on their taste?

Information available Consider that there are N users on a platform. Every user adds items that they like on their profile. These items have static attributes that describe the product. ...
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1answer
32 views

How to match a user with other users with similar interests based on their attributes?

Information Available Consider, there are 'n' users and they have these attributes and values ...
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0answers
17 views

Finding unobserved ratings using matrix factorization

Suppose that the utility matrix contains ratings of user on movies. How does matrix factorization find ratings for unobserved (user, movie) pair. Even though the purpose of the algorithm is to find ...
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0answers
18 views

Neighbourhood based approach on implicit feedback datasets

Is it possible to use a neighbourhood-based approach on implicit feedback dataset? I have a dataset with information about how many times a certain item was viewed by a particular user. I know that MF ...
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0answers
17 views

Including user-item pairs without interactions in implicit feedback dataset for recommender system

I have a dataset which contains information about how many times a particular user viewed certain item. So, I don't have rows for all combinations (where the value will be zero ofc because the user ...
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1answer
33 views

How to learn irrelevant words in an information retrieval system?

Right now my recommender system for information retrieval uses word embedding stogether with Tfidfs weights like written here: http://nadbordrozd.github.io/blog/2016/05/20/text-classification-with-...
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0answers
13 views

Is it possible to rank feature importance after training a recommender system?

I need to train a recommender system on some movie recommendation data. The thing is, I wanted to use a random forest for the model, since I know you can print a feature hierarchy, after training. I'...
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2answers
49 views

Classification model for recommender system?

I have some data for various customers choosing one of 'n' products or no product. I have some useful features for each customer. I can build a multi-class classification problem out of this data and ...
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2answers
950 views

Mean Average Precision python code

How do you compute MAP in python for evaluating recommender system effectiveness? Is there any library in sklearn or code in python for it? I would like to compute the effectiveness of my Recommender ...
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0answers
14 views

Item item similarity from both user data and content

I'm creating an item-item similarity matrix by combining implicit user data and static content data of the items. How can I determine the weights for these two data and the weights for different ...
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0answers
19 views

Does sum of embeddings make sense?

Referring to the LightFM model from paper Metadata Embeddings for User and Item Cold-start Recommendations, the model tries to learn $d$-dimensional user and item feature embeddings $e_f^U$ and $e_f^...