Week 05: using text as data

Published

May 20, 2025

Week 05: using text as data

Turning a series of short texts into tabular data: humans vs AI

Overview

In this lesson, students will be introduced to sentiment analysis, specifically applied to evaluating general positivity or negativity in football managers’ statements about match outcomes.

Learning Outcomes

By the end of the session, students will: - Gain hands-on experience with sentiment analysis. - Understand the complexities and limitations of sentiment analysis.

Materials

  • General Sentiment (positive/negative) rating scale HERE
  • CSV files:

Assignment review

  • Fancy graphs != good graphs (good graph <- careful design)
  • Precise interpretation >> BS
  • Less is more
  • Show only what you understand deeply

Lecture: NLP basics

  • Topic: Introduction to Sentiment Analysis
  • Key points:
    • Importance of text analysis and its applications
    • Introduction to Natural Language Processing (NLP): definition and applications
    • Key concepts in text analysis:
      • Tokenization
      • Preprocessing techniques
      • Feature extraction
    • Sentiment analysis: detecting emotion and tone in text
    • Practical examples from football managers’ post-match interviews
    • Limitations and challenges in text analysis, emphasizing contextual interpretation and ambiguity

Slides

domain lexicon

Practical Activity

Manual vs AI Sentiment Analysis Activity

  • Objective: Practice manually rating football manager statements as positive or negative.
  • Steps:
    1. Review general sentiment rating scale provided HERE
    2. Individually analyze and rate 5 provided test statements from student_test.csv.
    3. Now use AI to rate them.
    4. Try have a better domain lexicon.

Discuss experience, how AI helps, what could go wrong.

Prediction of score

  • Modeling choices of results
  • Think about how you would do it first
  • Check how AI thinks about, rate the examples and look at explanations
  • take the 5 examples, and compare your predictions vs the AI predictions

Discussion: Validation and Sentiment Analysis

  • Objective: Discuss validation techniques used in sentiment analysis.
  • Topics for discussion:
    • Differences between manual and AI ratings
    • Ground Truth
    • Introduction to validation methods:
    • If ground truth – can do confusion maztric, calculate accuracy
    • If no ground truth – measure agreement between humans and AI. test difference.
      • AI is average, but…
      • AI with persona?
      • AI biased ?

End of Week Discussion points

  • How precise is AI in sentiment analysis?
  • How did you compare to AI in terms of scores? How did any difference make you feel?
  • Can you think of a past project where AI could have helped you upgrade it?