Snowball Sampling for Channel Discovery

methodologydata-collectionsampling

Context

We needed a systematic method to discover and select which Telegram channels to monitor, starting from a limited set of known disinformation sources.

Decision

Implement snowball sampling via forwarding chain analysis: start with seed channels and expand through their most-forwarded sources.

Alternatives Considered

Keyword-based search

Pros
  • Simple to implement
  • Can discover channels by topic
Cons
  • Misses channels using coded language
  • High false positive rate

Expert-curated list only

Pros
  • High quality selection
  • Low noise
Cons
  • Limited scale
  • Biased toward known actors

Random sampling

Pros
  • Statistically unbiased
  • Broad coverage
Cons
  • Most channels are irrelevant
  • Extremely inefficient

Reasoning

Forwarding chains are the native propagation mechanism on Telegram. By tracing which channels are most frequently forwarded by known disinformation sources, we organically discover the network of channels participating in narrative dissemination. This produces a focused, relevant channel set while revealing network structure.

All decisions