Discourse & Dialogue


Sentiment Analysis: nearly everything you need to know MonkeyLearn

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Sentiment analysis is the automated process of understanding an opinion about a given subject from written or spoken language. In a world where we generate 2.5 quintillion bytes of data every day, sentiment analysis has become a key tool for making sense of that data. This has allowed companies to get key insights and automate all kind of processes. But… How does it work? What are the different approaches? What are its caveats and limitations? How can you use sentiment analysis in your business? Below, you'll find the answers to these questions and everything you need to know about sentiment analysis. No matter if you are an experienced data scientist a coder, a marketer, a product analyst, or if you're just getting started, this comprehensive guide is for you. How Does Sentiment Analysis Work? Sentiment Analysis also known as Opinion Mining is a field within Natural Language Processing (NLP) that builds systems that try to identify and extract opinions within text. Currently, sentiment analysis is a topic of great interest and development since it has many practical applications. Since publicly and privately available information over Internet is constantly growing, a large number of texts expressing opinions are available in review sites, forums, blogs, and social media. With the help of sentiment analysis systems, this unstructured information could be automatically transformed into structured data of public opinions about products, services, brands, politics, or any topic that people can express opinions about. This data can be very useful for commercial applications like marketing analysis, public relations, product reviews, net promoter scoring, product feedback, and customer service. Before going into further details, let's first give a definition of opinion. Text information can be broadly categorized into two main types: facts and opinions. Facts are objective expressions about something. Opinions are usually subjective expressions that describe people's sentiments, appraisals, and feelings toward a subject or topic. In an opinion, the entity the text talks about can be an object, its components, its aspects, its attributes, or its features.


r/MachineLearning - [D] Don't common sentiment analysis strategies seem unsatisfying?

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There's lots of great projects in Reddit in sentiment analysis, but almost all of the work I've seen focuses on individual posts, as if tweets or reddit comments was simply a list of thumbs up and thumbs down about issues. For example, context, which doesn't seem to get much discussion. One very basic example where this is important: a Reddit comment that itself is booing a negative comment is considered negative. Of course, the nested "negative" comment should actually be counted in favor of the original topic. The relevant fields in NLP would be coreference, and possibly other subfields involving semantics.


A Beginner's Guide on Sentiment Analysis with RNN – Towards Data Science

@machinelearnbot

In order to feed this data into our RNN, all input documents must have the same length. We start building our model architecture in the code cell below. We have imported some layers from Keras that you might need but feel free to use any other layers / transformations you like. To summarize, our model is a simple RNN model with 1 embedding, 1 LSTM and 1 dense layers. We first need to compile our model by specifying the loss function and optimizer we want to use while training, as well as any evaluation metrics we'd like to measure.


Semi-supervised and Transfer learning approaches for low resource sentiment classification

arXiv.org Machine Learning

Sentiment classification involves quantifying the affective reaction of a human to a document, media item or an event. Although researchers have investigated several methods to reliably infer sentiment from lexical, speech and body language cues, training a model with a small set of labeled datasets is still a challenge. For instance, in expanding sentiment analysis to new languages and cultures, it may not always be possible to obtain comprehensive labeled datasets. In this paper, we investigate the application of semi-supervised and transfer learning methods to improve performances on low resource sentiment classification tasks. We experiment with extracting dense feature representations, pre-training and manifold regularization in enhancing the performance of sentiment classification systems. Our goal is a coherent implementation of these methods and we evaluate the gains achieved by these methods in matched setting involving training and testing on a single corpus setting as well as two cross corpora settings. In both the cases, our experiments demonstrate that the proposed methods can significantly enhance the model performance against a purely supervised approach, particularly in cases involving a handful of training data.


Topic Modeling and Latent Dirichlet Allocation (LDA) in Python

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Topic modeling is a type of statistical modeling for discovering the abstract "topics" that occur in a collection of documents. Latent Dirichlet Allocation (LDA) is an example of topic model and is used to classify text in a document to a particular topic. It builds a topic per document model and words per topic model, modeled as Dirichlet distributions. Here we are going to apply LDA to a set of documents and split them into topics. The data set we'll use is a list of over one million news headlines published over a period of 15 years and can be downloaded from Kaggle.


Psychological State in Text: A Limitation of Sentiment Analysis

arXiv.org Artificial Intelligence

Starting with the idea that sentiment analysis models should be able to predict not only positive or negative but also other psychological states of a person, we implement a sentiment analysis model to investigate the relationship between the model and emotional state. We first examine psychological measurements of 64 participants and ask them to write a book report about a story. After that, we train our sentiment analysis model using crawled movie review data. We finally evaluate participants' writings, using the pretrained model as a concept of transfer learning. The result shows that sentiment analysis model performs good at predicting a score, but the score does not have any correlation with human's self-checked sentiment.



Text Mining and Sentiment Analysis - A Primer

@machinelearnbot

Over years, a crucial part of data-gathering behavior has revolved around what other people think. With the constantly growing popularity and availability of opinion-driven resources such as personal blogs and online review sites, new challenges and opportunities are emerging as people have started using advanced technologies to make decisions now. Sentiment analysis or opinion mining, refers to the use of computational linguistics, text analytics and natural language processing to identify and extract information from source materials. Sentiment analysis is considered one of the most popular applications of text analytics. The primary aspect of sentiment analysis includes data analysis on the body of the text for understanding the opinion expressed by it and other key factors comprising modality and mood.


How to Perform Sentiment Analysis in Excel Without Writing Code?

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We recently announced a new version of Excel Add-in which lets you perform state-of-the-art text analysis capabilities from the comforts of your spreadsheets without writing a single line of code. The add-in has been received very well by users working across different industry verticals like Market Research, Software, Consumer Goods, Education, etc. solving a variety of use-cases. Sentiment analysis has been the most used function of our Excel add-in closely followed by Emotion detection. Many of our users use sentiment analysis in Excel to quickly and accurately analyze the responses of their open-ended surveys, online chatter around their product/service or to analyze product reviews from e-commerce sites. In this blog post, we will discuss how to use the function Sentiment Analysis in Excel Add-in to do text analytics for any type of content.


An end-to-end Differentially Private Latent Dirichlet Allocation Using a Spectral Algorithm

arXiv.org Machine Learning

Latent Dirichlet Allocation (LDA) is a powerful probabilistic model used to cluster documents based on thematic structure. We provide end-to-end analysis of {\em differentially private\/} LDA learning models, based on a spectral algorithm with established theoretically guaranteed utility. The spectral algorithm involves a complex data flow, with multiple options for noise injection. We analyze the sensitivity and utility of different configurations of noise injection to characterize configurations that achieve least performance degradation under different operating regimes.