An n-gram is a contiguous sequence of n items (also called tokens) from a given text or speech sample. In the context of natural language processing, the items in an n-gram are usually words or characters.

It is a branch of artificial intelligence (AI) that deals with the interaction between computers and humans using natural language. It is computer science.Scikit-Learn provides accessible tools for training NLP models for classification, extraction, regression, and clustering. Moreover, it provides other useful capabilities such as dimensionality reduction, grid search, and cross-validation.

What is Keyword Generation?

Keyword generation is the process of creating a list of keywords or key phrases that are relevant to a particular topic or subject. It is an important step in search engine optimization (SEO) and online marketing, as it helps to improve the visibility and discoverability of a website or content.

How to Generate Keywords from Text?

A visual example of a keyword extraction process from a given text, highlighting key terms and phrases

Eskritor 2023-07-06

Why Should You Extract Keywords from a Text?

Keyword and keyphrase extraction from a text is helpful for several reasons:

Search engine optimization (SEO): If you have a website or blog, using relevant keywords in your content help improve your search engine rankings and make it easier for people to find your content. Also, word frequency matters for SEO. The number of keywords in a text affects the accessibility of the text.
Data analysis: Extracting keywords from a text helps you identify common themes or topics in a large dataset. This is useful for market research , sentiment analysis, and other types of data analysis.
Content categorization: By extracting keywords from text, categorize and organize your content more effectively. This makes it easier to find and retrieve specific pieces of information and also helps you identify gaps or redundancies in your content.
Text analysis and summarization: Extracting keywords also is used to summarize the main points or themes of a piece of text. This is useful for quickly understanding the content of a document or article, or for creating an abstract or summary of a longer piece of writing.

What is Keyword Extraction?

Keyword extraction is a natural language processing (NLP) technique used to automatically identify and extract the most important and relevant words and phrases from a text document. The extracted keywords are helpful for summarizing the document, categorizing it, or improving its searchability.

Keyword extraction algorithms typically use statistical and semantic techniques to identify the most relevant words and phrases. Some popular algorithms include TextRank , TF-IDF , and LSA .

What is TextRank?

TextRank is a graph-based algorithm that identifies the most important words and phrases in a document. It works based on their co-occurrence with other words and phrases in the text. The algorithm works by creating a graph where each node represents a word or phrase. The edges between the nodes represent their co-occurrence. The most important nodes are then identified using PageRank-like calculations.

What is TF-IDF?

TF-IDF (term frequency-inverse document frequency) is a statistical algorithm that identifies the most important words in a document based on their frequency and rarity in the document and in a corpus of documents. The algorithm works by assigning a weight to each word in the document based on its frequency and inverse document frequency.

What is LSA?

LSA (latent semantic analysis) is a semantic algorithm that identifies the most important words and phrases in a document based on their latent semantic relationships with other words and phrases in the text. The algorithm works by creating a matrix of the co-occurrence of words in the document, and then using singular value decomposition (SVD) to identify the most significant latent semantic relationships.

Keyword extraction is useful for various applications such as text summarization, information retrieval, text categorization, and search engine optimization.

How to Generate Keywords Automatically?

To generate keywords from text automatically, use various natural language processing (NLP) tools and techniques. Here are some steps to follow:

Use an NLP tool to extract the most frequent words and phrases from the text. Many programming languages have libraries for this, such as Python’s NLTK and spaCy.
Apply part-of-speech tagging to filter out non-relevant words such as articles, prepositions, and pronouns.
Use a keyword extraction algorithm such as TextRank, TF-IDF, or LSA to identify the most important and relevant keywords in the text. These algorithms typically use statistical and semantic analyses to identify keywords.
Set a threshold to filter out too common or rare keywords. This is done based on the frequency of occurrence of the keyword in the text or based on the document frequency of the keyword across a corpus of texts.
Organize the extracted keywords into groups or clusters based on their semantic similarity or topic.
Finally, review the generated keywords to ensure they are relevant and meaningful for the text.

What are Keyword Extractors?

Keyword extractors are computer programs or algorithms that work to automatically identify and extract the most relevant and significant words or phrases from a structured or unstructured text. The extracted keywords are useful for a variety of purposes. These keywords are useful for information retrieval, text classification, and search engine optimization (SEO). There are also some API-based extraction tools. It is one of the most used keyword extraction methods in data science. For more information, check online tutorials on webpages like GitHub .

Keyword extractors typically use a combination of techniques from natural language processing (NLP), machine learning, and statistical analysis to identify and extract keywords.

When it comes to evaluating the performance of keyword extractors, use some of the standard metrics in machine learning. Such metrics are accuracy, precision, recall, and F1 score.

An example of an API for extracting keywords is Textrazor. The Textrazor API is accessible using a variety of computer languages, including Python, Java, PHP, and others.

No, stopwords and keywords are not the same. Stopwords are common words that are removed from text data to reduce noise. Keywords are specific words or phrases that are relevant to the analyzed topic. Keywords are used to identify the main themes or concepts in a piece of text. Some of the stopwords in English are “the” and “a”.

What is RAKE?

RAKE (Rapid Automatic Keyword Extraction) is a keyword extraction algorithm. It is widely effective in natural language processing (NLP) and text mining applications. It is a simple and effective unsupervised algorithm that is capable of identifying and extracting the most relevant keywords and phrases from a single document.

What is YAKE?

YAKE (Yet Another Keyword Extractor) is a Python package for automatic keyword extraction. It is an open-source package that uses a statistical approach to identify and extract the most relevant keywords from a given text.

What is BERT-Embedding?

BERT (Bidirectional Encoder Representations from Transformers) embedding is a pre-trained deep learning model for natural language processing (NLP) developed by Google. It is based on the Transformer architecture. Also, it is trained on a large amount of textual data to generate context-aware word embeddings.

BERT embedding captures the contextual relationships between words in a sentence by taking into account the words before and after given the word. This process is also known as bidirectional training. This allows BERT to generate high-quality word embeddings that capture the nuances of language. This helps for providing a better representation of the meaning of a sentence.