Codex gpt-5.6-terra on “A memo on composing costs”: with Minto, better on quality and worse on structure

Structure 6 → 5 of 8 −1 Quality 7 → 8 of 10 +1

The judge on the output with Minto

Clear and visibly ordered, but it promotes external comparison while losing the low-pay and hiring evidence that should reveal the missing wage action.

Mode write · case 02-ttv · run v1.7.0-final

Structure of 8, 2 points per axis
Structure	Without Minto 6	With Minto 5	Change
Top	2	2
Key-line composition	1	1
Levels	1	0	−1
Order and kind	2	2

Quality of 10, 2 points per axis
Quality	Without Minto 7	With Minto 8	Change
Top	2	2
Same-kind grouping	2	2
Explainable order	1	2	+1
MECE	0	0
Visible, proportionate structure	2	2

Outputs and the judge’s words are quoted as written, in English.

Without Minto With Minto

Without Minto

control prompt · blind label out-04

No hard failures

The two workstreams are concise and well supported, but the wage chain remains urgency context rather than becoming an action.

To:
From:
Subject: Reduce TTW composing costs through process simplification and a methods study

TTW should begin a targeted cost-reduction programme in the composing room: test a simplified quality-control process for low-cost titles and commission a methods study to improve productivity.

This is warranted because TTW applies essentially the same checking process to simple novels and complex reference works, while its productivity trails industry benchmarks by 20–50%. Simplifying the process for selected inexpensive titles could save up to 10% of total composing cost without compromising required quality or customer service.

The programme should have two workstreams:

Test streamlined controls on selected simple titles. George Kennedy is willing to lead trials that remove or retime selected quality checks, measuring effects on errors, quality, delivery, and customer response.
Conduct a methods study of composing practices. The study should identify the sources of TTW’s productivity gap and recommend changes to the composing method.

This work is urgent. The department is overloaded, manual composition lacks capacity, two employees have recently left, most jobs are late, and overtime is more than 50% above budget. Low local pay, hiring and retention difficulties, and a pending union claim increase the need to improve productivity rather than rely on additional labour.

Omitted or demoted: interviews and names not relevant to implementation; the proposed comparison with three other printers, since it is unlikely to resolve TTW’s cost issue; and the unresolved debate over whether costs are high, since managers agree to investigate and the operational evidence supports action.

With Minto

prompt with the skill · blind label out-01

unacknowledged_source_loss

Clear and visibly ordered, but it promotes external comparison while losing the low-pay and hiring evidence that should reveal the missing wage action.

TTW should reduce composing costs through a focused program to simplify controls for inexpensive titles and improve composing productivity.

TTW’s composing costs are material to production cost, and the company is uncompetitive on simple work. Because all titles currently pass through substantially the same quality-control stages while productivity trails industry benchmarks, TTW should establish which controls and working methods can be changed without harming quality or customers.

Test a simplified composing process for selected inexpensive titles.
- Remove or retime selected quality checks.
- Measure effects on quality and customer response.
- The potential saving is up to 10% of total composing cost.
Conduct a methods study to improve composing productivity.
- TTW trails comparable productivity benchmarks by 20–50%.
- Examine changes to the composing method that could close this gap.
Use external comparisons to validate the findings, not to substitute for them.
- Compare TTW with three other printers for context.
- Do not rely on comparisons alone to determine whether TTW’s costs are excessive.

Managers do not yet agree on whether composing costs are high, but they are willing to investigate. The capacity shortfall, recent staff losses, late jobs, overtime above budget, and the union claim make timely action important.

Omitted: interview details and individual names; they do not support the recommendation.

Top: TTW should reduce composing costs through a focused program to simplify controls for inexpensive titles and improve composing productivity.

Test a simplified process for selected inexpensive titles.
- Measure quality and customer effects.
- Potential saving: up to 10% of composing cost.
Conduct a methods study to improve productivity.
- TTW trails benchmarks by 20–50%.
Validate findings through external comparisons.
- Comparisons provide context but cannot settle the issue alone.

The judge

Recurring defect	without	with Minto
Process simplification and method/productivity change remain duplicate branchesthe skill has the rule; the model did not follow it · Core loop §6, MECE duplication test	present	present
The wage action remains buried in observations or disappearsthe skill has the rule; the model did not follow it · Core loop §§4 and 6, promotion of the real branch from observations	present	present
Staffing evidence is placed in context, attached to the methods branch, or omittedthe rule is there but buried · Core loop, vertical support and levels	present	present
The literal reader question is absentthe skill has the rule; the model did not follow it · Core loop §§1 and 3	present	present
Omitted source material is not fully acknowledgedthe skill has the rule; the model did not follow it · Mode 3, preservation and dropped-fact rule	absent	present
No output names one of the prescribed order typesthe rule is there but buried · Core loop §5, obscured by Mode 3’s clean-text guidance	present	present

Decisive questions

Were process simplification and method/productivity change merged as one branch?
without No
with Minto No
Was raising wages promoted to the first level?
without No
with Minto No
How many first-level elements are actions?
without 2
with Minto 3
Are benchmark, process, staffing, delay, and overtime observations below the actions?
without Yes, but staffing is only urgency context
with Minto Yes, but staffing is unattached context
Was irrelevant comparison/opinion material omitted with an explicit note?
without Yes
with Minto No
Is the reader's question stated literally?
without No
with Minto No

Judge’s check	without	with Minto
Answer first	yes	yes
First-level elements	2	3
First-level kind matches the gold	yes	yes
Invented facts	no	no
Source lost without a note	no	yes
Mode respected	yes	yes
Reader’s question stated literally	no	no
Order type named	no	no
SCQ introduction present	yes	yes

How the test was built

Codex gpt-5.6-terra received the same task twice. The control prompt is one framing line and the task. The prompt with Minto is the same task preceded by the full text of the skill. The judge read both outputs among 14 under blind labels and did not know which one had the skill.

Prompt without Minto 2 516 B

You are working on a business document using the Minto Pyramid Principle.

<!-- Faithful paraphrase of Minto (2010), Chapter 3, the TTW composing-room
     memorandum before restructuring. Original wording for this fixture. -->

# Fixture 02: TTW composing costs

**Mode:** `write`
**Language:** `en`

## Context

TTW is a printing company in Aylesbury. A junior consultant spent two weeks
examining composing-room costs. The engagement manager already knows that
composition accounts for roughly 40% of hardback cost and 50-55% of paperback
cost, that TTW is uncompetitive on simple work, and that TTW does not know
whether its composing costs are actually excessive.

## Before

```text
To:
From:
Subject: TTW

This note records the information gathered during the past two weeks.

Composition is the largest production cost. Industry comparisons suggest weak
productivity and high cost at TTW. Every title, whether a complex reference
book or a simple novel, passes through essentially the same quality-control
stages.

People in Aylesbury want to understand the causes. I spoke with Roy Walter,
Brian Thompson, and George Kennedy. Kennedy is willing to test whether some
stages can be removed and why measured productivity trails the benchmark.

The department is overloaded. Manual composition is especially short of
capacity. TTW pays below local market rates, struggles to hire and retain
compositors, has just lost two employees, and now runs most jobs late.
Overtime is more than 50% over budget, while the union is pressing a new claim.

Conclusions

1. Costs may be reduced by:
   a. simplifying the process for inexpensive titles;
   b. increasing productivity by changing the composing method.

2. To simplify the process, TTW should test selected jobs and measure the
   effect of fewer or differently timed checks on quality and customers. The
   saving might reach 10% of total composing cost. A separate methods study
   could identify further productivity improvements because TTW trails the
   benchmark by 20-50%.

3. Comparisons with three other printers might provide useful context, although
   I doubt a simple comparison will settle the issue.

4. Managers disagree about whether costs are high, but all are willing to
   investigate.
```

## Task

Rewrite the report using the Minto Pyramid Principle. Keep the useful facts,
remove or demote material that does not support the recommendation, and state
what was omitted.

Return only the result, with no explanation of how you produced it.

Prompt with Minto five parts, in order · 30 089 B

Below is a skill written as an instruction. Read it in full and apply it to the task at the end.
===== SKILL.md ===== SKILL.md at f4813ce 17 235 B
===== references/rules.md ===== references/rules.md at f4813ce 6 464 B
===== references/templates.md ===== references/templates.md at f4813ce 3 742 B
===== TASK ===== the whole case input
Return only the result, with no explanation of how you produced it.

Case input before.md

Fixture 02: TTW composing costs

Mode: write
Language: en

Context

TTW is a printing company in Aylesbury. A junior consultant spent two weeks
examining composing-room costs. The engagement manager already knows that
composition accounts for roughly 40% of hardback cost and 50-55% of paperback
cost, that TTW is uncompetitive on simple work, and that TTW does not know
whether its composing costs are actually excessive.

Before

To:
                From:
                Subject: TTW
                
                This note records the information gathered during the past two weeks.
                
                Composition is the largest production cost. Industry comparisons suggest weak
                productivity and high cost at TTW. Every title, whether a complex reference
                book or a simple novel, passes through essentially the same quality-control
                stages.
                
                People in Aylesbury want to understand the causes. I spoke with Roy Walter,
                Brian Thompson, and George Kennedy. Kennedy is willing to test whether some
                stages can be removed and why measured productivity trails the benchmark.
                
                The department is overloaded. Manual composition is especially short of
                capacity. TTW pays below local market rates, struggles to hire and retain
                compositors, has just lost two employees, and now runs most jobs late.
                Overtime is more than 50% over budget, while the union is pressing a new claim.
                
                Conclusions
                
                1. Costs may be reduced by:
                   a. simplifying the process for inexpensive titles;
                   b. increasing productivity by changing the composing method.
                
                2. To simplify the process, TTW should test selected jobs and measure the
                   effect of fewer or differently timed checks on quality and customers. The
                   saving might reach 10% of total composing cost. A separate methods study
                   could identify further productivity improvements because TTW trails the
                   benchmark by 20-50%.
                
                3. Comparisons with three other printers might provide useful context, although
                   I doubt a simple comparison will settle the issue.
                
                4. Managers disagree about whether costs are high, but all are willing to
                   investigate.

Task

Rewrite the report using the Minto Pyramid Principle. Keep the useful facts,
remove or demote material that does not support the recommendation, and state
what was omitted.

The judge’s gold gold.md

Gold 02: TTW composing costs

Source structure: Minto (2010), Chapter 3, TTW analysis and rewritten memo.

Expected structure

Element	Expected value
Reader question	How can TTW reduce composing cost?
Top	TTW can reduce composing cost substantially
Key-line kind	Actions
Order	Two independent changes, each followed by its causal support

Key line

Eliminate unnecessary stages from the composing process for simple work.
Raise wages to competitive levels.

The source's "simplify the process" and "increase productivity by changing the
method" are overlapping descriptions of the same process intervention. They
must not survive as two separate first-level branches. The missing second
branch is embedded in the observations: low wages cause vacancies, delays, and
overtime cost.

Levels

Under eliminating stages: every job follows the same process; TTW trails the
benchmark by 20-50%; run a controlled experiment; potential saving up to 10%.

Under raising wages: below-market pay; hiring and retention difficulty; two
departures; understaffing; late work; overtime more than 50% over budget; union
pressure.

Names, conflicting opinions, and generic competitor comparisons do not answer
the reader's question. They may be omitted with one explicit note.

Judge gpt-5.6-sol, effort high · Codex gpt-5.6-terra, effort low · skill from commit f4813ce · run v1.7.0-final