How knowledge in computing and AI actually decays, consolidates, and gets reused: the evidence behind claims that skills expire fast, the cognitive-science mechanisms behind durable learning, what happens — for an individual or a whole research field — to the knowledge that doesn't consolidate, and how a technology's publicity can diverge from its actual utility along the way.
"The half-life of a computer science degree is five years." "AI skills expire every two years." "Medical knowledge doubles every 73 days." These numbers circulate constantly, always with the same implication: things are…
Gartner analyst Jackie Fenn published the first version of the Hype Cycle in a February 1995 research note, "When to Leap on the Hype Cycle" — a hand-drawn curve plotting a handful of technologies against a five-stage…
The Half-Life of Knowledge establishes three tiers — foundational, applied, ephemeral — and shows real domains sitting at each one. What it doesn't give is a way to place a new, arbitrary technology into one of those…
The Hype Cycle as a Second-Order Cybernetic System proposes three shapes a technology's publicity-versus-utility curve can take — recovers, recycles, or dies in the Trough — and Placing a Technology on the Half-Life…
The Hype Cycle as a Second-Order Cybernetic System argues the Trough of Disillusionment is usually a correction to an overfit model of a technology's utility, not proof the utility collapsed. That reframing has direct…
Does a Research Field Sleep? shows AI research surviving two winters because specific foundational work — Werbos's backpropagation thesis, Pearl's Bayesian networks, LeCun's early convolutional networks, Vapnik's…
"The problem with rote learning is not that it fails to produce recall. It's that it fails to produce anything else." — a common paraphrase of the research this page is built on, not a direct quote from any one source
This page sits between two others on this site that, read separately, leave a gap. Memorising vs Learning makes the cognitive-science case for interleaved, spaced practice over blocked, massed practice, but stops at the…
The Half-Life of Knowledge describes ephemeral, applied, and foundational knowledge as stages in a decay chain, and treats a foundational schema as the stable end-state that's left once the volatile, specific material…
"Research and learning are the same thing, just with different audiences." — Pat Parslow
A note on register before the argument: The Half-Life of Knowledge and How Sleep Turns Ephemeral Memory Into Foundational Knowledge build on cited, checked empirical literature. This page is different in kind — I'm…
The rest of this cluster establishes the pieces separately: The Half-Life of Knowledge sets out the three tiers as a decay chain; How Sleep Turns Ephemeral Memory Into Foundational Knowledge gives the individual-scale…