top of page

Unraveling Automated Topic Extraction: LDA & Python in Action

  • Writer: Nadav Harari
    Nadav Harari
  • Oct 26, 2023
  • 4 min read

Updated: Oct 31, 2023


In the vast ocean of digital content, how do you pinpoint the themes that resonate most? The answer lies in the magic of topic modeling, a game-changer for content analysis, SEO, and digital marketing. Grasping the core topics of your content can be the difference between blending in and standing out. In this article, I'll unveil a Python script that's been my secret weapon: an automated tool that dives deep into web pages to extract these vital topics using the power of LDA. If you've ever wondered how to get an edge in understanding and optimizing your content, especially in comparison to competitors, you're about to discover a tool that could revolutionize your approach.

What is LDA (Latent Dirichlet Allocation)?


At its core, LDA is a statistical model that dives into the heart of your content, seeking out hidden, or "latent", themes. Imagine it as a detective, sifting through the words in your documents, identifying patterns where certain words often appear together. These patterns aren't by chance; they reveal underlying topics. LDA operates on a probabilistic foundation, meaning it calculates the likelihood of particular topics leading to the observed collection of words in your content.


Why Topic Modeling?


Picture a vast library with thousands of books but no catalog system. Daunting, right? Topic modeling is akin to creating that catalog, making sense of enormous volumes of text. For businesses and content creators, understanding these primary themes is invaluable. It shapes content strategies, ensuring you're hitting the right notes for your audience. Furthermore, it allows for sharp competitive analysis, highlighting what themes competitors might be focusing on and revealing potential gaps in the market. By discerning the essence of vast content collections, topic modeling becomes a compass in the often overwhelming world of digital content.



"By analyzing the most prevalent keywords and themes, you can ensure that the content remains true to its core topic."

Script Breakdown:


Required Libraries:

The script employs Python libraries including pandas for data manipulation, BeautifulSoup for web scraping, gensim for the LDA model, and nltk for natural language processing.


Fetching Web Content:

The get_page_text function is tasked with pulling content from a specified URL. It uses requests to access the webpage and BeautifulSoup to parse and extract the textual content.


Topic Extraction with LDA:

Within the extract_topics function, common words or 'stopwords' are first filtered out. The remaining text is then tokenized, breaking it down into individual words or terms. The LDA model is subsequently applied to these tokens. The outcome? A list of keywords, each paired with a score that indicates its relevance to the discovered topic. Importantly, these keywords in the output file are sorted in descending order based on their scores, ensuring the most relevant terms are prioritized.


Processing Excel Input and Output:

Input file: The script begins by reading an Excel file containing URLs. These URLs can be those of competing articles that rank for the same keyword as your main article.




Output file: Post analysis, it crafts an output Excel file, listing each URL alongside its corresponding topics and scores. A notable feature is the color-coding, providing a visual cue to identify recurring topics.


Practical Applications:


Competitive Analysis:

By extracting the most prevalent topics from your content and comparing them with those of the top 10 URLs on Google for a primary SEO keyword, you get a direct comparison. This deep dive offers a clear view of the thematic landscape, highlighting potential areas of improvement and revealing where your content might have an edge.


Content Analysis:

Every piece of content has a core focus—a central theme or message it aims to convey. But does the actual content align with this intended focus? By analyzing the most prevalent keywords and themes, you can ensure that the content remains true to its core topic. If discrepancies arise, it's a cue for realignment, ensuring that readers receive a coherent and on-topic narrative.


Limitations and Considerations:


Quality of Topics:

While LDA is a powerful tool for topic modeling, the clarity and interpretability of the topics it uncovers can be inconsistent. Some topics may be immediately recognizable and well-defined, while others might appear vague or overlapping. In such cases, manual inspection and intervention become essential to refine and make sense of these topics.


Number of Topics:

One of the inherent challenges in using LDA is determining the right number of topics for a given dataset. Too few might oversimplify the content, while too many could lead to redundancy. Finding the optimal number often requires a blend of domain expertise and additional evaluation techniques, ensuring the topics are both meaningful and comprehensive.


Google's NLP Option:

It's worth noting that there are alternative methods to topic extraction. Google's NLP API, for instance, offers entity analysis which can identify and categorize key entities within the text. While this can be advantageous for certain applications, it offers a different perspective compared to the probabilistic and topic-centric nature of LDA. Depending on the specific goal, one might be more suitable than the other.


Conclusion:

The LDA-driven Python script I've dissected provides a potent tool for SEO professionals and content creators alike. By extracting and neatly sorting the most prevalent keywords and themes from content, it offers a clear roadmap of the textual landscape. This isn't just data—it's actionable insight.


With the core themes or keywords of a piece laid out in the output file, SEOs can prioritize their keyword targeting strategy, ensuring they're focusing on the most impactful terms. Content creators can validate that their content remains anchored to its primary focus, adjusting as necessary for optimal audience resonance.



FAQ


What will be the Effect if I Increase the 'num_topics' Variable (within the 'extract_topics' function) in the Script from 3 to 5?

Increasing the num_topics variable might give you a more detailed breakdown of the themes within each document, but it's essential to ensure that the number of topics aligns well with the actual content diversity to maintain interpretability.

What's the Difference Between LDA and NLP in Our Case Study?

What are the Prerequisites and Steps to Use the Script in Google Colab?









About the Author

I am Nadav Harari, an SEO specialist with a passion for data analysis and digital marketing. Feel free to contact me at Nadav@hararidigital.com or follow me on LinkedIn.



 
 
bottom of page