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Questions and Answers
What is one application of text classification mentioned in the content?
What is one application of text classification mentioned in the content?
spam filtering
What technique involves breaking down text into a collection of words and disregarding grammar and word order?
What technique involves breaking down text into a collection of words and disregarding grammar and word order?
Bag of Words (BoW) model
In the Bag of Words model, after tokenization and vocabulary building, what is the final step?
In the Bag of Words model, after tokenization and vocabulary building, what is the final step?
Vectorization
What are some challenges mentioned in the text regarding representing multiple words together?
What are some challenges mentioned in the text regarding representing multiple words together?
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Stemming is a preprocessing technique that involves expanding words to their root form.
Stemming is a preprocessing technique that involves expanding words to their root form.
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What does part-of-speech tagging involve?
What does part-of-speech tagging involve?
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What is sentiment analysis also known as?
What is sentiment analysis also known as?
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Valence Aware Dictionary for sEntiment Reasoning (VADER) is an example of a __________.
Valence Aware Dictionary for sEntiment Reasoning (VADER) is an example of a __________.
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Which technology captures word relationships using a co-occurrence matrix?
Which technology captures word relationships using a co-occurrence matrix?
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What is the trade-off offered by distributed databases?
What is the trade-off offered by distributed databases?
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Latent Dirichlet Allocation (LDA) is a generative probabilistic model used for sentiment analysis.
Latent Dirichlet Allocation (LDA) is a generative probabilistic model used for sentiment analysis.
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According to the CAP Theorem, what are the three aspects that can be selected?
According to the CAP Theorem, what are the three aspects that can be selected?
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Match the measure for document similarity with its description:
Match the measure for document similarity with its description:
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NoSQL databases do not have to be write-consistent all the time.
NoSQL databases do not have to be write-consistent all the time.
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NoSQL databases allow more tailored database designs with an emphasis on application logic and optimization patterns, shifting from hard design rules to __________ designs.
NoSQL databases allow more tailored database designs with an emphasis on application logic and optimization patterns, shifting from hard design rules to __________ designs.
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What is the Hadoop Ecosystem known for?
What is the Hadoop Ecosystem known for?
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What is Apache Spark primarily used for?
What is Apache Spark primarily used for?
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Study Notes
Text Mining and Natural Language Processing
- Text classification: assigns a discrete label to a text document, where the set of possible labels is Y.
- Applications: spam filtering, analysis of electronic health records, sentiment analysis, and more.
Bag of Words Model
- Simplifies text by breaking it down into a collection of words, disregarding grammar and word order, but maintaining multiplicity (frequency of each word's appearance).
- Steps:
- Tokenization: breaks text into individual words or tokens.
- Vocabulary building: creates a list of unique words.
- Vectorization: converts text into numerical vectors.
Tokenization
- Types of tokens:
- Word tokens: most common type, e.g., ["Natural", "Language", "Processing", "is", "fascinating"].
- Subword tokens: useful for languages with rich morphology, e.g., "unhappiness" -> ["un", "happiness"].
- Character tokens: beneficial for languages with large character sets, e.g., "你好" -> ["你", "好"].
- Sentence tokens: treats entire sentences as tokens, e.g., sentence segmentation.
Challenges
- Handling multiple words together (n-grams).
- Dealing with punctuation, which can affect word meaning.
- Stemming: reduces words to their root form, e.g., "running", "runner", and "ran" -> "run".
Part-of-Speech Tagging
- Labels each token with its part of speech, encoding information about the word's definition and use in context.
Sentiment Analysis
- Measures the sentiment of phrases or chunks of text.
- Applications: brand monitoring, crises management, customer feedback analysis, market research, targeted marketing campaigns, and influencer marketing.
- Approaches:
- Rule-based algorithm composed by a human.
- Machine learning model learned from data.
- Valence Aware Dictionary for sEntiment Reasoning (VADER).
Advanced Approaches
- Apply neural networks, e.g., decoder models like GPT.
Clustering Documents
- Needs a measure for document similarity.
- Measures:
- Jaccard Distance.
- Edit distance.
- Term Frequency-Inverse Document Frequency (TF-IDF) extension of the bag of words model.### TF-IDF and Word Embeddings
- TF-IDF enhances the Bag of Words (BoW) model by weighing terms based on their importance, reducing the impact of frequently occurring but less informative words.
- Word embeddings are dense vector representations of words that capture semantic meanings and relationships.
- Unlike BoW, which represents words as sparse vectors with high dimensionality, word embeddings map words into a continuous vector space of lower dimensionality.
Word Embeddings
- Word embeddings allow similar words to have similar vector representations, enabling the model to capture semantic relationships.
- Words with similar meanings are close to each other in the vector space (e.g., "king" and "queen" are closer to each other than to "dog").
- Word embeddings typically have lower dimensionality (e.g., 100 to 300 dimensions) compared to the size of the vocabulary in BoW.
Contextual Information
- Embeddings can capture context if trained on large corpora, allowing them to understand the meaning of words in context.
Word Embedding Models
- GloVe captures word relationships using a co-occurrence matrix, which counts how often words appear together in a corpus.
- FastText extends Word2Vec by representing words as bags of character n-grams, allowing it to handle out-of-vocabulary words better.
- Contextual Embeddings (e.g., BERT, ELMo) generate word embeddings that depend on the context in which the words appear, providing dynamic representations for words in different contexts.
Clustering and Topic Modeling
- Standard ML clustering: K-means (partitive), Hierarchical (agglomerative)
- Topic modeling: Latent Dirichlet Allocation (LDA) is a generative probabilistic model used for topic modeling.
- LDA assumes that documents are mixtures of topics, and topics are mixtures of words.
Latent Dirichlet Allocation (LDA)
- The goal of LDA is to discover the hidden topic structure in a collection of documents.
- Each topic is characterized by a distribution over a fixed vocabulary of words.
- Document Representation: Each document is represented as a distribution over topics.
Distributed Databases
- Distributed databases offer scalability at a trade-off.
- NoSQL databases offer flexibility in design and scalability.
- CAP Theorem: Consistency, Availability, and Partition Tolerance.
Big Data and Analytics
- Big data leaves us with two big questions: how to store big data and how to process big data.
- Distributed computing is the key to processing big data.
- Apache Spark is a unified engine for big data processing.
Apache Spark
- Spark is a fast and general engine for large-scale data processing.
- Resilient Distributed Datasets (RDD) are Spark's primary data abstraction.
- DataFrames are like distributed in-memory tables with named columns and schemas.
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Description
This quiz covers text mining, natural language processing, sentiment analysis, customer segmentation, and more in the context of marketing. It explores the application of big data in marketing analytics and optimization.