Keyword Extraction Guide: Identify Keywords in Text

Keyword identification is one of the critical aspects of content analysis, but it can be time-intensive when done manually.

One of the greatest time-savers is keyword extraction — the automated process of extracting relevant words and phrases from the text. It is a text analysis method that automatically extracts vital information from a page. But how does it work? How do you identify keywords in text

There are several techniques for performing keyword extraction. They include the simple statistical approach, advanced machine-learning process, and linguistic approach. This guide discusses keyword extraction, its importance, its applications, and how to identify keywords in text.

What Is Keyword Extraction?

Keyword extraction, also known as keyword analysis, is an approach to analyzing text and automatically extracting the most relevant words. This technique helps summarize text content and recognize the key topics discussed. 

Keyword extraction utilizes machine learning, artificial intelligence, and natural language processing to disintegrate human language, so machines can understand and analyze it. It helps you sift through documents, business reports, online forums and reviews, and others to find keywords.

The keyword extraction process involves identifying the most relevant words or phrases that can be stated as a ‘main point’ of a text.

Why Is Keyword Extraction Important?

Most of the data we generate daily is unstructured and unorganized, making it difficult to analyze and process. Keyword extraction helps you identify a large dataset’s most relevant words and phrases in seconds. No matter your field, keyword extraction tools are invaluable in automatic data indexing, text summarization, or keyword identification.

With automated keyword extraction, businesses can process and analyze customer data more efficiently to gain valuable insight into topics customers are discussing. Keyword extraction helps you identify what your customers consider relevant and the aspects of your product that need improvement. This way, you can understand your customer base better and develop a data-driven business strategy.

Keyword extraction is also vital in academics. It helps to find relevant keywords within substantial data sets, like new articles, journals, or papers, without reading the whole content.

Keyword extraction has many advantages, including:

1. Scalability

Keyword extraction automatically analyzes a massive dataset in seconds to extract the most important words and phrases. Manual text analysis can be time-consuming and inefficient; it would take excessive time for a human to analyze large quantities of text documents.

Automated keyword extraction tools have been widely used to analyze text documents, extracting keywords from them quickly and accurately. This gives analysts time to focus on more critical tasks.

2. Consistent Criteria

Manual text analysis is filled with inconsistencies. These inconsistencies can lead to unsatisfactory results and fruitless searches. Keyword extraction results are consistent because the process is based on rules and predefined parameters. 

3. Real-Time Analysis

In real-time, keyword extraction can analyze customer reviews, surveys, and social media posts. This way, you keep abreast of what consumers are saying about your goods.

Photo by Mel Poole on Unsplash

Applications of Keyword Extraction

Keyword extraction can be used across fields to obtain the most relevant keywords in a given text without actually reading the entire text. The automated process is vital to businesses and professionals who want to expedite manual or time-consuming text analysis processes.

For example, customer service managers trying to analyze customer interactions can use keyword extraction to analyze and process text quickly. Researchers going through several online papers about a specific topic can also use this technique.

Here are some of the cases where keyword extraction is useful: 

1. Social Media Monitoring

People use social media platforms to express their thoughts and opinions on different topics. Companies can use keyword extraction to follow customer conversion on social media, understand their audience, improve their products and prevent public relations disasters.

Keyword extractions can give insight into what people say about your product or brand on social media. You can use this technique to follow trends, conduct market research, and monitor your competition.

2. Business Intelligence

Keyword extraction can also be helpful for business intelligence (BI), like market research and competitive analysis. With this technique, you can gather information from product reviews, social media, and conversions about topics of interest. This information will help you better understand public opinion about a topic issue, which you could use to improve your product or service.

You can also use keyword extraction to compare your product reviews with your competition. This way, you can understand your audience’s pain points and make data-driven decisions to improve your offerings.

3. Customer Feedback

Online surveys are a great way to determine how customers perceive your product and learn which aspects customers value or criticize the most. Survey results can give you solid insights to make data-driven business decisions. Manually analyzing survey responses can be time-consuming and inefficient, leading to inconsistencies and errors.

Keyword extraction offers an easy way to identify the most common words and phrases in customer responses without manually going through each of them.

4. Search Engine Optimization (SEO)

A significant factor in Search Engine Optimization is identifying the keywords to target on your website.

Keyword extraction can help you sift through the website content of your competitors and extract their most frequent words. This is a great way to find content writing opportunities. And by using semantic keyword grouping to classify keywords and phrases frequently used together, you’ll have the edge over your competition.

5. Product Analytics

Product managers use data to support their decisions. Customer feedback, from customer support interactions to survey responses, is vital for a successful data-driven product strategy.

With large volumes of customer feedback data to process, manually extracting the most relevant keywords from a text can take time and effort. Keyword extraction methods help product managers identify frequent terms or phrases mentioned by their customers. This way, they find new opportunities for improvement.

a closed white book beside a green leaf plant
Photo by Olia Gozha on Unsplash

Identify Keywords in Text: How Keyword Extraction Works

Keyword extraction simplifies the process of identifying relevant words and phrases within the unorganized text. It automates workflows, saving you a lot of time. It also gives you data-driven, actionable insights to help you make better business decisions.

Keyword extraction models are relatively easy to implement. There are several methods for automating keyword extraction, from simple statistical approaches to advanced machine-learning approaches.

Here are some of the ways to identify keywords in text.

Simple Statistical Approaches

This is one of the easiest methods for identifying keywords and phrases in a text. Several statistical approaches exist, including word frequency, word collocations, and co-occurrences.

Using these approaches, you don’t need training data to extract relevant keywords in a text. But, since they only rely on statistics, they may overlook words that are mentioned once in a text but are still considered relevant.

Below are some of the types of statistical approaches.

1. Word Frequency

Word frequency involves listing the words and phrases that occur the most within a text. This is useful for businesses in identifying recurrent terms in reviews and the most common problems in customer support interactions. 

The word frequency approach thinks of documents as just a bunch of words. It leaves out fundamental aspects like meaning, structure, grammar, and sequence of words. For example, it cannot detect synonyms.

2. Word Collocations and Co-Occurrences

Collocations are words that often go together. They can be bi-grams – two terms that appear adjacently, like “pay attention” or “fast food.” They can also be tri-grams – a group of three words, like “out of business.”

Word collocations count separate words as one and help determine the semantic structure of a text. 

Co-occurrences mean two terms that appear together in the text corpus. They don’t have to be next to each other but have semantic proximity.


TF-IDF – frequency-inverse document frequency is a formula that measures how relevant a term is to a document in a group of documents. It estimates a term frequency, i.e., the number of times a term appears in a text. It then compares it with the inverse document frequency – how rare or common that term is in the entire data set.

Multiplying these two numbers provides the TF-IDF score of a term in a document. The greater the score, the more relevant the term is to the document. When applied to keyword extraction, this metric helps to identify the most relevant terms in a document. That is, the ones with the highest scores. This can be useful for tasks like tagging customer support tickets and analyzing customer feedback.

4. RAKE (Rapid Automatic Keyword Extraction)

RAKE is a popular keyword extraction method that uses stop words and phrase delimiters to find the most relevant words in a text. It splits the text into a list of words, removes stop words, and returns a list of content words. The algorithm then generates a matrix of word co-occurrences. Each row shows how many times a given content word appears with every other word in the candidate phrases. 

After the matrix is developed, words are given a score. The score can be calculated as the degree of the word divided by its frequency.

a person using a MacBook Pro and typing on the keyboard
Photo by Glenn Carstens-Peters on Unsplash

Linguistic Approaches

Keyword extraction methods use linguistic information about texts and the term they contain. At times, morphological or syntactic information (like part of speech of words) is used to determine which keywords to extract. Some parts of speech get higher scores (e.g., nouns and noun phrases) because they generally contain more information than other categories.

Other methods use discourse markers (i.e., phrases that assemble discourse into segments, like however or moreover). 

Machine Learning Approaches

Machine learning is a subdivision of artificial intelligence that builds systems capable of learning or improving performance based on the data they consume. Machine learning-based systems are used for keyword extraction. They process unstructured data by breaking it down into something they can understand. They do this by transforming data into vectors that contain different features representative of a text.

Machine learning techniques like Support Vector Machines (SVM) and deep learning can be used to extract relevant keywords in a text.

Wrapping Up

Keyword extraction is the process of extracting keywords that appear in a large dataset, such as an article, blog post, or internet forum. It is the automated process of extracting a text’s most important words and phrases.

Keyword extraction is one of the most widely applied research methods in content marketing, and business analysis. It saves time, and effort and, for large-scale text analysis, enables faster and more accurate results. It also automates workflows, saving a lot of time and energy and providing actionable insights to help you make better business decisions. 

This is an effective guide that discussed keyword extraction and how to identify keywords in text.

Co-Founder of INK, Alexander crafts magical tools for web marketing. SEO and AI expert. He is a smart creative, a builder of amazing things. He loves to study “how” and “why” humans and AI make decisions.

White Label Keyword Research Tools Worth Considering

White-label keyword research tools are becoming increasingly popular amongst online marketers. These powerful platforms offer many benefits that can help…

February 4, 2023

A Guide to Advanced Competitor Keyword Analysis

Assessing the competition can effectively identify your website’s strengths, weaknesses, and opportunities. Knowing your competitors’ SEO strategies and tracking their…

February 4, 2023

A Guide to Effective Keyword Rank Tracking

Everybody wants to be on top of Search Engine Results Pages (SERPs). And knowing where your website and content rank…

February 4, 2023

How to Find Negative Keywords in Google Ads

The whole point of using ads is to target potential customers. You don’t want your ads showing up for unrelated…

February 4, 2023

The Google Search Console Guide for Keyword Research

Crafting an effective keyword research strategy is no small feat. It requires an in-depth understanding of your audience, a comprehensive…

February 4, 2023

How to Pick Effective Focus Keywords

A focus keyword for Search Engine Optimization (SEO) is critical to ensuring the success of any digital marketing strategy. Not…

February 4, 2023