Understanding Public Perceptions on Cannabis Legalization: Using ML & AI

What do people in Thailand really think about cannabis legalization? That’s the question WeStride faculty members Smith Tripornkanokrat, Nuttachai Kulthammanit, and Veerachai Suwatvanich set out to answer in their recent study, "Sentiment Analysis of Twitter Data Based on Cannabis Legalization in Thailand." By examining thousands of tweets over a five-year period, the research gives a fascinating glimpse into how Thai society is responding to this controversial issue. The study has been recognized for its impactful findings and was recently accepted for publication in the SAU Journal of Science & Technology, a tier 2 journal indexed on the Thai-Journal Citation Index Centre.

A Mixed Picture of Public Sentiment

Even though Thailand has legalized cannabis for medical and industrial purposes, the study found that public opinion online remains largely skeptical. Conversations on Twitter reveal widespread concerns about societal harm, including increased drug use, risks for youth, and potential links to crime. These fears often overshadow discussions about the medical or industrial benefits of cannabis.

Interestingly, only a small fraction of tweets—between 0.2% and 5.5%—shared positive sentiments about cannabis for medical use. This suggests that while legalization has sparked interest, public opinion is still deeply divided and leans toward caution.

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Figure 1: The visualization of cluster predictions based on RoBERTa results suggests that Cluster 0 primarily represents negative sentiments, accounting for 53.6% of the data, Cluster 1 indicates a mix of sentiments with a slight positive leaning, comprising 35.9% of the data, and Cluster 2 likely represents positive sentiments, making up 10.5% of the data.

What’s Being Said Online?

The research also shed light on the nature of online discussions about cannabis. Unfortunately, a large portion of tweets contained harmful or inappropriate content:

• 31-35% included hate speech or harassment.
• 21-23% referenced sexual content.
• 7-11% contained dangerous or harmful behavior.

These findings highlight the challenges of fostering a healthy and informed public dialogue around such a polarizing issue.

The Three Sentiment Groups

The study categorized public sentiment into three distinct groups:

1. Strongly Opposed: People in this group are concerned about cannabis legalization leading to societal decay and see it as a risk to Thailand’s moral fabric.
2. Mixed Feelings: These individuals are cautiously optimistic, recognizing the potential benefits but remaining wary of potential harm.
3. Supportive: A smaller group that champions personal freedom and the medical advantages of cannabis use.

As co-author Veerachai Suwatvanich explained, “While discussions about cannabis are growing, the conversation is still dominated by fears of its societal impact, particularly on young people and social stability.”

Bridging the Gap

This research comes at a crucial time as Thailand navigates the challenges of implementing cannabis legalization. Smith Tripornkanokrat noted, “Our study highlights the importance of addressing public fears and misunderstandings. Without better communication and education, the benefits of legalization may be overshadowed by negativity.”