Difference between revisions of "Supervised Machine Learning for Fake News Detection"
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Revision as of 20:06, 27 April 2019
Contents
Declaration
Acknowledgement
Thanks for Muhammad, Graham and Mark
Abstract
Introduction
Chapter 1
Chapter 2 - Training a Supervised Machine Learning Model
Supervised text Classification for fake news detection Using Machine Learning Models
Procedure
- The Dataset
- Splitting the data into Train and Test data
- Cleaning the data
- Building the Document-Term Matrix
- Model Building
- Cross validation
- Making predictions from the model created and displaying a Confusion matrix
Results
Summary of Results
Algorithms | Author | Package | Keyword | Accuracy | |||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Kaggle fake news dataset | Fake news Detector dataset | Gofaaas Fake News Dataset | |||||||||
Test data (30% of the dataset) | Cross validation | Test data (30% of the dataset) |
Cross validation | Test data (30% of the dataset) | Cross validation | Using the Kaggle Model* | Using the Detector Model** | ||||
Naive Bayes | Bayes, Thomas | We used RTextTools, which depends on e1071 | NB* | ||||||||
Support vector machine | Meyer et al., 2012 | We used RTextTools, which depends on e1071 | SVM* | ||||||||
Random forest | Liawand Wiener, 2002 | We used RTextTools, which depends on randomForest | RF | ||||||||
Extreme Gradient Boosting | Chen & Guestrin, 2016 | xgboost | XGBOOST* | ||||||||
General linearized models | Friedman et al., 2010 | We used RTextTools, which depends on wglmnet | GLMNET* | ||||||||
Maximum entropy | Jurka, 2012 | We used RTextTools, which depends on maxent | MAXENT* | ||||||||
* Accuracy of predictions made with the Kaggle Fake News Model over the Gofaaas Fake New Dataset
** Accuracy of predictions made with the Fake News Detector Model over the Gofaaas Fake New Dataset |
Evaluation of Results
We evaluate our approach in different settings. First, weperform cross-validation on our noisy training set; second,and more importantly, we train models on the training setand validate them against a manually created gold standard.17Moreover, we evaluate two variants, i.e., including and exclud-ing user features. [smb:home/adelo/1-system/1-disco_local/1-mis_archivos/1-pe/1-ciencia/1-computacion/2-data_analysis-machine_learning/gofaaaz-machine_learning/5-References/7-Weakly_supervised_searning_for_fake_news_detection_on_twitter.pdf]
The Gofaaas-Fake News Detector R Package
Installation
Functions
Datasets used
Kaggle Fake News Dataset
https://www.kaggle.com/c/fake-news/data
Distribution of the data:
The distribution of Stance
classes in train_stances.csv
is as follows:
rows | unrelated | discuss | agree | disagree |
---|---|---|---|---|
49972 | 0.73131 | 0.17828 | 0.0736012 | 0.0168094 |
Fake News Detector Dataset
Gofaaas Fake News Dataset
Algorithms
Naive Bayes
Naïve Bayes is based on the Bayesian theorem, there in order to understand Naïve Bayes it is important to first understand the Bayesian theorem.
Bayesian theorem is a mathematical formula for determining conditional probability which is the probability of something, happening given that something else has already occurred.
- P(c|x) is the posterior probability of class (target) given predictor (attribute).
- P(c) is the prior probability of class.
- P(x|c) is the likelihood which is the probability of predictor given class.
- P(x) is the prior probability of predictor.
Prior probability, in Bayesian statistical inference, is the probability of an event before new data is collected.
Posterior probability is the revised probability of an event occurring after taking into consideration new information.
In statistical terms, the posterior probability is the probability of event A occurring given that event B has occurred.
Support vector machine
Random forest
Extreme Gradient Boosting
The XGBoost R package
XGBoost - Extreme Gradient Boosting:
- https://xgboost.readthedocs.io/en/latest/
- https://cran.r-project.org/web/packages/xgboost/index.html
The RTextTools package
RTextTools - A Supervised Learning Package for Text Classification:
- https://journal.r-project.org/archive/2013/RJ-2013-001/RJ-2013-001.pdf
- http://www.rtexttools.com/
- https://cran.r-project.org/web/packages/RTextTools/index.html
Chapter 3 - Gofaas Web App
A way to interact, test and display the model results
Conclusion