Week 11: Minimum intervention

Restoration practice — reviving one piece of dead software with the smallest possible change, the way a conservator stabilises a painting.

3 May 2027

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Learning outcomes#

By the end of this week you should be able to:

1. apply the principle of minimum intervention to a concrete restoration
2. produce a restoration log adequate for another practitioner to audit
3. distinguish stabilisation from modernisation, and justify the boundary chosen

Outline#

• The conservation principle: stabilise, do not repaint. Change only what is necessary to make it work, and document every change.
• What “minimum” means in practice: updating a dependency vs rewriting the code that uses it. Shim vs migration. Compatibility vs modernisation.
• Case study: HTMX — old ideas (HTML-over-the-wire, progressive enhancement) revived in modern packaging. Is it restoration or reinvention?
• The restoration log: a complete list of changes, in order, each with a justification. The log is as important as the code.
• What you deliberately do not change: the temptation to refactor, modernise, improve. Every improvement is a departure from the original.
• When restoration is not appropriate: projects that should stay dead

Required reading#

• Brandi, C. (2005 [1963]) Theory of Restoration, trans. C. Rockwell. Istituto Centrale per il Restauro / Nardini.
• ICOMOS (1964) International Charter for the Conservation and Restoration of Monuments and Sites (The Venice Charter).

Further reading#

• Feathers, M.C. (2004) Working Effectively with Legacy Code. Prentice Hall. Chapters 1–6.
• Muñoz Viñas, S. (2005) Contemporary Theory of Conservation. Elsevier.

Seminar questions#

1. The Venice Charter requires that restoration work be distinguishable from the original and reversible. What is the software equivalent of reversibility — a branch, a flag, a patch file?
2. Brandi distinguishes the historical from the aesthetic instance of a work. Does code have an aesthetic instance, and would preserving it ever justify leaving a bug in place?
3. Feathers defines legacy code as code without tests. Does adding tests to your dig site violate minimum intervention?