Week 6 Lab: Reading the Difference
Two exercises at the screen. Read a real diff of this site's own syllabus, then use conflicting metadata to decide which file in a folder is current
Version 1.5 · Supersedes v1.4 · Status: CURRENT
- v1.4: Put the exercise-one answer behind a reveal instead of leaving it in the open prose.
- v1.3: Added the worked answer for what the diff reports and cannot report.
- v1.2: Moved the choose-before-revealing instruction into the widget itself.
- v1.1: Updated to name the current teaching staff.
- v1.0: Rewritten sentence by sentence for style, not substance.
29 March 2027
This lab is two exercises, both done here on the page. There is nothing to bring. Work through them in order: the second one depends on having seen what the first one refuses to tell you.
One: read a diff of this site#
The syllabus you are enrolled under has been revised once. Its version header says so, and says what changed. Below is the machine’s account of the same revision, computed from the two week lists by the method in the lecture.
Syllabus, v1.0 against v2.0
The week list as first published, and as it stands now. Switch between the two versions and the difference between them. The comparison is computed from the two lists by the method described in the lecture. No line is marked by hand.
3 lines removed, 2 added.
- unchanged: Week 1: final_FINAL_revised2
- unchanged: Week 2: What Is a File?
- unchanged: Week 3: Copies & Clones
- unchanged: Week 4: Save As
- unchanged: Week 5: Before Git
- unchanged: Week 6: The Diff
- unchanged: Week 7: Merge Conflict
- unchanged: Week 8: The Canonical Version
- unchanged: Week 9: Sync Is a Lie
- unchanged: Week 10: Conversion Damage
- removed: Week 11: Forensic Versioning
- removed: Week 12: Provenance & Archives
- removed: Week 13: Archive or Delete?
- added: Week 11: Provenance & Forensics
- added: Week 12: Archive or Delete?
Three lines removed and two added, for a revision a person would describe in one clause: two weeks were merged into one. The comparison cannot say that. It also cannot say that Archive or Delete? did not change: that week was renumbered from 13 to 12, and a renumbered line is a different line, so the diff reports it as a deletion and an addition. One of the five differences below is not a difference. Nothing in the output distinguishes it from the ones that are.
Write down two things. First, the thing the diff reports accurately, which is worth stating plainly because it is genuinely useful. Second, the thing it cannot report: read the version header on the syllabus and compare what a person wrote about that revision with what the comparison produced. The gap between the two is the subject of this week.
Show the answer
The diff reports five lines changed, three removed and two added, and that count is accurate and reproducible by anyone who reruns the same comparison on the same two lists. What it cannot report is why. The syllabus’s own version header says the two removed weeks, Forensic Versioning and Provenance & Archives, were merged because they were “the same work looked at from two directions, not two topics.” Nothing in either week list states a relationship like that between two lines. String equality has no way to represent it.
One of the five differences it reports is not a difference. Find it before you read the note underneath, and say what would have to change about the comparison for it to know.
Two: decide which file is current#
The diff told you where two versions differ. It did not tell you which to keep, because that is not a question about differences. Here is a folder where you have to answer it anyway.
Which file is current?
Seven files, recovered from one shared folder. The metadata is intact and it does not agree with itself. Inspect it, choose the file you would send if someone asked for the proposal, then read the reasoning. Nothing is scored. The reasoning is the point, and it covers every file, not only the one you picked.
The authoritative file is proposal_final2.docx. Not because of its name, and not because it is the newest. It is not. The two artefacts that settle it are the export, which fixes what that file contained at 16:52, and the lock file, which shows that the person who later wroteproposal_FIXED.docx had the wrong document open.
Note which ground you were using. If you chose proposal_FIXED.docx, you were applying recency, which is the ground a sync service would have applied, and it is wrong here for a reason no timestamp can show you: the most recent edit was made to a stale copy. Reconstructing the lineage is what defeats it.
Write down the ground you were actually using (recency, lineage, corroboration, or the filename) and whether the reasoning changed your mind. If it did not, say what would have.
Afterwards#
Identify the one artefact in that package that nobody created on purpose, and what it establishes that no deliberately written file in the folder does. That artefact is the whole lesson: the most reliable evidence in a folder is usually the residue of an operation rather than anything a person chose to record.
This package is a small, resolvable version of the Which One Is Real? assessment. That one is larger, some of its evidence contradicts itself, and it does not show you the answer.
The spec
What you bring to the session. Written so a reader can tell whether it has been met without asking you.
- the one thing the syllabus diff reports accurately and the one thing it cannot report, both written down
- a file chosen from the inspection package before reading the reasoning, and the ground you used to choose it
- one artefact in that package that nobody created deliberately, and what it establishes
Teaching team
- Dashiell Petrov: tutor