Picking a target worth the clock
A toy chatbot does not exercise the skill this course cares about — deciding what to cut under a real approval-step constraint — so a target needs an unfamiliar domain, structure worth rendering and a decision a human must own; picking one badly is how a practice run becomes an afternoon of styling.
You have a kit, a mock backend that streams convincingly, and a written cut list. The remaining input to a practice run is the blank Target product field at the top of the log entry, and it decides more about what the run measures than anything you do afterwards. Fill it badly and three hours produce a row in a table and no information.
There are two ways to fill it badly, and they fail differently. A target that is too small — a chat box with a system prompt — leaves you two hours of clock and no decisions to spend them on, so the run quietly becomes an afternoon of styling. A target that is too vague — “something for a logistics company” — spends hour one on the specification you were supposed to arrive with, and the phase table records that as domain comprehension when it was really indecision.
Four tests a target has to pass
This is this course’s own screen, not a finding from anywhere. It exists because the runs have to vary in the ways that matter and hold constant in the ways that do not.
- There is a decision a human must accept, correct or reject before anything downstream fires. Not a confirmation dialog. A real judgment the agent got roughly right and a person has to adjust, with the evidence for it visible next to the control.
- You do not already know the domain. If you can name the entities and their relationships from memory, the run measures recall. Freight demurrage, clinical prior authorisation, lease abstraction, insurance subrogation — the interesting ones are the ones where you have to read something first.
- There is structure to render, not just text. An agentic surface earns its complexity from extracted fields, confidences, source references and a run trace. A stream of prose has none of that and skips the whole part of the build worth timing.
- It is unlike the previous run’s target. Rule 5 of the practice log. Six variations on invoice approval measure how well you remember invoice approval.
A fifth, softer one: the failure case should be interesting. A target where a wrong answer is obviously wrong teaches you nothing about designing the correction step, which is where most of the real design work in an agentic surface lives.
What deliberate practice actually requires
Repetition against a clock is not automatically practice, and it is worth being precise about the difference rather than gesturing at the popular version. Ericsson — whose work the ten-thousand-hours story is a distortion of — restated his own criteria in a 2019 paper with Kyle Harwell. Four conditions: individualised training designed by a well-qualified teacher; a communicated goal the trainee can internally represent; an activity giving immediate feedback; and repeated revised attempts approaching that goal.
Map the six runs onto them honestly, including the weak spot:
| Criterion | What supplies it here |
|---|---|
| A goal you can internally represent | The demo claim sentence, written before the run. If you cannot say what you would show, the goal is not represented. |
| Immediate feedback | The three-hour wall and the phase table. You find out whether the cut list was right the same afternoon, not a quarter later. |
| Repeated attempts, revised | Six runs, each starting from the previous run’s what the kit should have had column. |
| A well-qualified teacher | The weakest leg. Nobody is watching you run. The read-back and this teaching agent are the substitute, and a substitute is what they are. |
What Ericsson does not say about your targets
The four criteria motivate caring about task design in general. They say nothing about toy targets versus realistic ones, in software or anywhere else, and the paper does not use the word transferable. No source found for this course compares a chatbot practice target against a portfolio-company-shaped one. The four tests above are this course’s design judgment about what rehearses the transfer it cares about, and that is all they are.
The limits are worth stating in the same breath. The largest meta-analysis of deliberate practice — Macnamara, Hambrick and Oswald (2014), 88 studies and 11,135 participants — found practice explained 26% of performance variance in games, 21% in music, 18% in sports, 4% in education and under 1% in professions. Software development is a profession. The authors note professions is also where the measurement is weakest, which cuts both ways. Either way, no single design choice inside your practice, including which target you pick, should be expected to dominate the outcome. Pick well because the alternative wastes an afternoon, not because target selection is the lever.
And the popular version, since somebody will bring it up: Ericsson himself pointed out that Gladwell never used the term deliberate practice and folded in activities such as public performance and ordinary work that violate the criteria. The ten thousand hours was a group average for the top tier of Berlin violin students at age twenty, against roughly 7,800 hours for the next group down. It was never a threshold. If you invoke it, you are invoking something Ericsson disputed.
The target bank
Pick targets in a batch, in advance, when the clock is not running. Choosing under pressure costs clock, and worse, it biases toward whatever you already know how to build — which is precisely the target that measures nothing.
Six candidates, six domains, each with the approval step named. Shape yours like this:
Domain Agent does Human approves
Freight billing Flags demurrage overcharges The disputed line items
Clinical intake Drafts prior-auth packets Codes and clinical rationale
Commercial leases Abstracts renewal terms Extracted dates and options
Claims subrogation Ranks recovery candidates Which files get pursued
Field service Builds a dispatch plan Route and parts substitutions
Trade compliance Classifies goods for tariff The HS code and its basisEach row is unfamiliar enough to need reading, structured enough to render, and carries a decision a person has to own. None of them is a chat interface, and none of them is a domain you have shipped.
Four ways a target goes wrong
- The general assistant. “An agent that helps with X.” No approval step, no artifact, and the build collapses into a message list. The run ends early and you fill the time with styling.
- The one you have opinions about. If you already know the schema, hour one disappears and the run looks fast for a reason the kit had nothing to do with. That contaminates the comparison against your baseline as badly as starting from an existing project would.
- The visual problem in disguise. A target whose hard part is a chart, a canvas or a diagram. Real work, wrong course. The clock goes to rendering, and the log records nothing about agentic surfaces.
- The one with nothing to get wrong. If the agent cannot plausibly produce a bad answer, there is nothing for the human to correct, and the correction interaction is the part you are here to get fast at.
Check your recall
Answer from memory — no scrolling back.
Retrieval check
Your last run went smoothly and finished with twenty minutes spare. Is that a good sign about the kit?
Check your answer
Not on its own, and the target is the first thing to suspect. A run that never forced a cut is a run whose constraint did not bind, which usually means the target was too small or too familiar rather than that you got faster. Check the log: if nothing came off the cut list, the run measured comfort.
The diagnostic question is what the human had to approve, and whether the agent could have got it wrong in a way that mattered. If the answer is thin, the twenty spare minutes belong to the target, not to the kit.
Hands on
Build the target bank
Done when: learning/prototyping-velocity/PRACTICE-LOG.md carries a Target bank of six candidates from six different domains, each with its approval step, its demo claim and a note on why it is unfamiliar — and the next run’s target chosen from it.
- Write six candidates, one per domain, none of them a domain you have shipped in. Portfolio-company shaped: something a mid-market business pays people to do by hand today.
- For each, write the approval step in one sentence: what the agent decides, what a human sees, and what they can change. If you cannot write that sentence, the candidate fails the first test and gets replaced rather than reworded.
- For each, write the demo claim — the sentence you would say while showing it. This is the internally represented goal the run is aimed at, and it is what the cut list protects.
- For each, name one thing you would have to read before you could model the domain. If there is nothing, the target is too familiar to measure anything.
- Cross out any candidate whose hard part is visual rather than agentic, and any where a wrong answer would be obviously wrong. Replace them rather than keeping the list at six by force.
- Pick the next run’s target from the bank and check it against the previous run’s domain. Bring the bank into the chat and I will push hardest on any candidate whose approval step is really a confirmation dialog.
What this does not cover
The bank says what to build against. It says nothing about what to build with, and the runs are where that question gets answered — v0, Claude Code, Cursor and Figma Make will come up in the room, and an opinion assembled from vendor pages is worth less than nothing there. Building a position from your own runs, and knowing what does and does not count as evidence for it, is the next lesson, An evidenced position on the tools.
Nor does this lesson tell you what six filled-in rows mean once you have them. Comparing runs whose targets deliberately differ is harder than it looks, and the reading of the log gets its own lesson at the end of this module.
Read this next — primary source
Deliberate Practice and Proposed Limits on the Effects of PracticeK. Anders Ericsson & Kyle Harwell, Frontiers in Psychology, 25 October 2019 — free, open access
Read this instead of anything written about the ten thousand hours. Ericsson restates his own criteria in plain terms and then spends most of the paper on the part the popular version drops: what does not qualify, and why ordinary work and public performance fail the definition. Take from it the four conditions and the discipline of checking an activity against them. Do not take from it any claim about practice targets in software, because it studies neither software nor target selection.
Stuck, curious, or think this lesson is wrong? Ask your teaching agent. The lessons are the scaffold; the conversation is where the learning gets unstuck.