Information Dissemination and Rumor Control in Emergency Evacuation

Problem Description
In mass emergency evacuations (e.g., fire, terrorist attack), the efficiency and accuracy of information dissemination directly affect the evacuation outcome. Delays in truthful information or the spread of rumors can lead to crowd panic, poor decision-making, route congestion, and even stampedes. The core of this problem is: How to design an information dissemination mechanism so that critical instructions can reach the majority of people quickly and reliably, while suppressing the generation and spread of rumors?

Explanation of the Problem-Solving Process

Step 1: Understand the Key Challenges of Information Dissemination
During emergency evacuation, the information environment has three main characteristics:

1. Information Asymmetry: Only some people (e.g., those near the alarm source) can perceive the danger immediately, while others rely on indirect information.
2. Channel Competition: Official broadcasts may be drowned out by noise, and verbal transmission among noisy crowds is prone to distortion.
3. Psychological Amplification Effect: Under panic, individuals tend to over-interpret ambiguous information, accelerating rumor spread.
   Key Goal: Shorten the time for truthful information to cover the entire population and reduce the signal-to-noise ratio of rumors.

Step 2: Construct a Multi-Channel Collaborative Dissemination Network
A single channel (e.g., loudspeaker) is prone to failure, requiring a layered design:

• Primary Channel (High Authority): Emergency broadcasts, instructions from the fire command center. Advantage is high authority, but may be limited by distance.
• Auxiliary Channels (Relay Nodes): Train staff and volunteers as "information relay stations" to repeat instructions at key locations according to the plan.
• Spontaneous Channels (Civilian Networks): Utilize mobile phone groups and social media to push official information, but be wary of forged messages.
  Design Key Point: The primary channel provides the information source, auxiliary channels solve the "last mile" coverage, and spontaneous channels need guidance, not blockage.

Step 3: Quantify Information Dissemination Efficiency Metrics
Use two core metrics to evaluate the plan:

1. Penetration Rate: The proportion of the population receiving accurate information within time t. The ideal state is an exponential growth curve (e.g., through social networks).
2. Rumor Suppression Rate: The ratio of rumor spread speed to truthful information speed. If the ratio > 1, rumors have the advantage.
   Example Calculation: Assuming each person can inform 2 neighbors per minute, starting with 10 people knowing the truth, a group of 100 people would need about log₂(100/10) ≈ 3.5 minutes to cover over 90%; if a rumor starts simultaneously from 1 person, priority must be given to ensuring a higher starting number for the truthful information.

Step 4: Integrate Anti-Rumor Mechanisms
Rumor control requires a combination of "dredging and blocking":

• Active Immunization: Inform people in advance about common rumor patterns (e.g., "East Gate is closed") in the预案, and clearly mark alternative exits with signs.
• Real-Time Correction: Monitor keywords on social platforms; once a rumor is detected, immediately use the primary channel to broadcast a correction (e.g., "East Gate is open normally, do not believe the rumor").
• Utilize Key Persons: Identify natural leaders within the group (e.g., teachers, security guards), prioritize conveying accurate information to them, and leverage their influence to calm others.

Step 5: Dynamic Adjustment and Feedback Loop
Evacuation is a dynamic process, and information strategy needs iteration:

• Monitor crowd movement via cameras or drones. If crowds are found stagnant in certain areas (possibly due to rumor-induced blockage), initiate targeted broadcasts immediately.
• Collect feedback post-evacuation, analyze rumor origins (e.g., unclear signage in a certain area), and optimize physical space and information signage.

Summary
Effective information management = Authoritative Source × Multi-Channel Coverage × Anti-Rumor Mechanism × Dynamic Monitoring. The core idea is to treat information as a "soft resource" equally important as exit capacity, and through systematic design, make it flow efficiently and resist interference.