Week 1: What 99% Promises

The one analytic move this course runs for twelve weeks — claim, source event, verdict — and why a local simulator is an instrument rather than a convenience.

23 February 2027

Open the slides

Slides

This course has four lectures. This is the first, and it is the only one that introduces something you will use every single week.

What this lecture carries#

The move. Three terms, defined once and used for twelve weeks:

• A claim is anything the interface asserts. A number is a claim. So is the word “Finalising”. So is a bar that accelerates, a spinner that never changes speed, and a control that greys out. So, sometimes, is an absence — a screen that shows nothing is claiming that nothing needs saying.
• A source event is something the underlying process actually emits, at a time you could write down. Not something the process does — something it reports.
• A verdict is what you conclude about the pair. This week you have three: sourced, unsourceable, and not determinable from outside.

Why the simulator is not a shortcut. Every transfer in this course is local and fake. That is not because real networks are inconvenient; it is because a claim about a failure you cannot reproduce is not a claim anybody can check. The simulator is what makes the rest of the semester falsifiable.

The course’s one rule, stated in week 1 so it can be held against you later: nothing on your screen is allowed to assert more than your evidence supports. This applies to your interface, and it applies to the prose you write about your interface.

What it sets up#

What it assumes#

Nothing. If you can write a function that takes a callback, you have the prerequisites.

A worked example#

Take one claim from the case this lecture opens with — a bar that reaches 99% in nine seconds — and run it through the three terms rather than the table.

The claim is not “99%”. It is the rate: a bar that covers 99 points in nine seconds tells a reader the last point takes about a tenth of a second. Nobody wrote that sentence; the movement asserts it.

The source event would have to be something that reports how long the remaining work takes. No such event exists — the process reports bytes, and the last point is not bytes.

So the verdict is unsourceable, and notice what that does not mean. It does not mean the designer lied. It means the screen carried a claim the system had no way of supporting, which is a different and much more common thing.

What this lecture cannot settle#

This move tells you what a claim rests on. It does not tell you whether the interface is any good.

An unsourceable claim can be the right design decision — taken knowingly, for a reason, with a cost. Week 10 gives that case its own verdict. Until then, resist converting an analysis into a judgement: you are building the instrument, not using it to condemn anything.

If you miss the hour#

The slides carry the argument in the order it was made, and this week’s reading is listed on the studio page. The studio on Thursday assumes the vocabulary above rather than re-teaching it, so read the deck before you arrive rather than after.