Hashtags

Assesses hashtag frequency in a text column, highlighting usage trends and potential dataset bias or spam.

Purpose

The Hashtags test is designed to measure the frequency of hashtags used within a given text column in a dataset. It is particularly useful for natural language processing tasks such as text classification and text summarization. The goal is to identify common trends and patterns in the use of hashtags, which can serve as critical indicators or features within a machine learning model.

Test Mechanism

The test implements a regular expression (regex) to extract all hashtags from the specified text column. For each hashtag found, it makes a tally of its occurrences. It then outputs a list of the top N hashtags (default is 25, but customizable), sorted by their counts in descending order. The results are also visualized in a bar plot, with frequency counts on the y-axis and the corresponding hashtags on the x-axis.

Signs of High Risk

  • A low diversity in the usage of hashtags, as indicated by a few hashtags being used disproportionately more than others.
  • Repeated usage of one or few hashtags can be indicative of spam or a biased dataset.
  • If there are no or extremely few hashtags found in the dataset, it perhaps signifies that the text data does not contain structured social media data.

Strengths

  • Provides a concise visual representation of the frequency of hashtags, which can be critical for understanding trends about a particular topic in text data.
  • Instrumental in tasks specifically related to social media text analytics, such as opinion analysis and trend discovery.
  • Adaptable, allowing the flexibility to determine the number of top hashtags to be analyzed.

Limitations

  • Assumes the presence of hashtags and therefore may not be applicable for text datasets that do not contain hashtags (e.g., formal documents, scientific literature).
  • Language-specific limitations of hashtag formulations are not taken into account.
  • Does not account for typographical errors, variations, or synonyms in hashtags.
  • Does not provide context or sentiment associated with the hashtags, so the information provided may have limited utility on its own.