2008 · Languages & software

An interface you can rely on

Abstraction lets a system change inside while preserving its promises outside.

Barbara Liskov

2008Turing Award

Visual guide

The prize, pictured

Open full-size ↗Download poster ↓中文版海报 ↗

An interface you can rely on: Abstraction lets a system change inside while preserving its promises outside. — Original AI-generated infographic by Curionode. Read the text version below for the full explanation.

Read the poster text

Specify
Define the public operations.
Hide
Keep representation details internal.
Substitute
Preserve behaviour as implementations change.

Well-designed interfaces and dependable distributed services make large software systems easier to evolve.

Hiding details is useful only when the exposed interface describes the properties that clients actually need.

01 · The idea

In everyday language

Barbara Liskov developed foundations of programming-language and system design, especially data abstraction, fault tolerance and distributed computing. An abstract data type offers operations with clear behaviour while hiding its representation. This separation helps people reason about components and replace implementations without disrupting their clients.

Why it matters

Well-designed interfaces and dependable distributed services make large software systems easier to evolve.

02 · The people

Who brought the idea to life?

Barbara Liskov

Barbara Liskov developed principles that let programmers build complex software from understandable components. At MIT, her work on CLU made data abstraction and modular programming concrete through language design and implementation. She also contributed to distributed systems, fault tolerance, and behavioral subtyping. Her research showed how clear interfaces and carefully specified behavior can support both reliable programs and systems spread across multiple machines.

Read the biography ↗

03 · Read further