Tubes and bubbles topological confinement of YouTube recommendations
Number of recommendations with a lifespan T ≥ R for various thresholds θ ≥ 0%, θ ≥ 50% and θ ≥ 90%} (averages are central lines, along with their 95%-confidence intervals). A lifespan of T means that a recommendation appeared at least θ% of the time over a sliding window of r = 20 successive requests, at two distinct moments at least T requests apart. Inset: average presence of a suggestion over its lifespan as a function of the lifespan (again for the three thresholds). Suggestions with longer lifespans are generally appearing very frequently during their lifespan (T → 2000 ⇒ 〈f(T)〉 → 100%).