Specify an application before choosing a model
Specify the application’s job before choosing a model.
Reviewed: 2026-10-03
Source-based teaching example · Fictional data
Narration: Microsoft Mark · locally synthesized

00:00:00.000 — What you will learn

Specify the application’s job before choosing a model.

Visual description:
Specify the application’s job before choosing a model.

00:00:06.458 — The idea

Define allowed inputs, outputs and actions. Try a simple lookup as the baseline. Use generated prose only when it helps, and verify it against the returned record.

Visual description:
Define allowed inputs, outputs and actions. Try a simple lookup as the baseline. Use generated prose only when it helps, and verify it against the returned record.

00:00:21.292 — One useful term

Application contract. The required behavior, input rules and explicit success or failure states.

Visual description:
The required behavior, input rules and explicit success or failure states.

00:00:31.708 — A worked example

A guest may read public workshop record P, which starts at 10:00. Restricted record R is not available to the guest. The task needs no sending, file edits or autonomous agent.

Visual description:
A guest may read public workshop record P, which starts at 10:00. Restricted record R is not available to the guest. The task needs no sending, file edits or autonomous agent.

00:00:47.333 — Your turn to think

Does an AI model need to decide whether the guest may read R? Pause and decide before continuing.

Visual description:
Does an AI model need to decide whether the guest may read R?
Pause the video if you need more time.

00:01:04.458 — Why this answer works

No. Application permissions control access. Return an explicit denial rather than an inferred replacement.

Visual description:
No. Application permissions control access. Return an explicit denial rather than an inferred replacement.

00:01:15.167 — Check 1

Use only permitted records.

Visual description:
Use only permitted records.

00:01:20.083 — Check 2

Keep missing and denied states explicit.

Visual description:
Keep missing and denied states explicit.

00:01:25.458 — Check 3

Do not add unneeded side effects.

Visual description:
Do not add unneeded side effects.

00:01:30.750 — Now try a different case

Open the lesson and try its different practice case. Use every check in the full task. Watching alone does not mark the lesson complete.

Visual description:
Open the lesson
Try the new case
Check and revise
The full task and its requirements are in the linked lesson.