Era 08 / 15 · Second AI Winter 1987–1993

The Second Winter

Expert systems proved brittle; the LISP-machine market collapsed.

Beat 1 · Concrete

The wall of rules cracks

Every case got its own hand-laid rule — until new cases split the wall apart.

An expert-system rule wall fracturing under new cases A wall built of rule-bricks. As new cases arrive they strike the wall, cracks spread between the bricks, and a section breaks loose and falls. A cracked expert-system rule wall A wall of rule-bricks crossed by coral cracks, with a corner section broken loose.

Beat 2 · Abstract

Cost up, value down — then collapse

Upkeep climbed past worth; the specialized LISP-machine market then fell away.

Maintenance cost rising past business value, then the LISP-machine market collapsing Two curves cross: a coral maintenance-cost curve rising while a steel-blue business-value curve falls. After the crossover, the tall LISP-machine market column drops to almost nothing as cheap general hardware wins. 1987 1993 magnitude crossover LISP-machine market

Beat 3 · Interactive

Add new cases · watch it fail

Each new case needs more patch-rules; structural integrity slides toward failure.

Patch-rules needed 76
Structural integrity 73%

Brittle, but standing.

Drag — more cases, more patches, less integrity

Footnotes & nods

~1987

The market vanishes

The specialized LISP-machine business collapsed almost overnight as its reason to exist eroded.

Cheaper iron

General workstations win

Sun and other general-purpose machines ran the same work for far less — dedicated AI hardware lost.

Upkeep

Brittle & costly

Expert systems couldn't generalize; every new case meant more hand-written rules to maintain.