Fact check: What methods do organizers use to count attendance at political demonstrations?

1. Summary of the results

There are multiple established methods for counting attendance at political demonstrations, ranging from traditional manual techniques to advanced technological solutions ^[1]. The traditional Jacobs Method involves estimating crowd density using grid squares, while modern approaches utilize CCTV footage, thermal cameras, and various indirect measurements like public transport usage and mobile network data ^[1]. A particularly promising development comes from University of São Paulo researchers, who developed an AI-powered drone imagery system that reduced the margin of error from 30% to 12% ^[2].

2. Missing context/alternative viewpoints

The question of crowd counting has become increasingly politicized, as evidenced by recent controversies involving Donald Trump and Kamala Harris regarding AI-generated crowd photos ^[3]. This highlights how crowd size estimates can create "erroneous perceptions among voters and analysts" ^[2]. Each counting method has its own limitations:

• Traditional methods struggle with non-uniform crowd distribution
• Mobile crowds that change size during events pose challenges
• Indirect methods (like transport data) may not capture all attendees ^[1]

3. Potential misinformation/bias in the original statement

The original question assumes there might be standardized methods for counting crowds, when in reality, the process is complex and often contested. Several groups have vested interests in crowd size reporting:

• Political figures and organizers: Often benefit from higher numbers to demonstrate support and momentum
• Opposition groups: May benefit from lower numbers to diminish perceived support
• Technology companies: Companies developing new counting solutions (like the São Paulo researchers) benefit from highlighting the unreliability of traditional methods ^[2]
• Media organizations: Need to report numbers but often lack reliable verification methods

The development of more objective counting methods, like the AI-drone system ^[2], suggests a growing recognition of the need to counter politically motivated inflation of crowd numbers.