One decision at a time · F99

Differential Decision Lab — F99

The Decision Lab presents short reasoning problems that isolate one classification move at a time — selecting the best-supported category, eliminating an alternative, spotting the decisive or a contradicting piece of evidence, choosing what to ask next, recognising when information is genuinely insufficient, or revising a provisional answer once new information appears. It is deliberately shorter and more focused than a full Case Lab vignette, so you can practise one reasoning step at a time before combining them in a full case.

Each item asks for a single reasoning move — eliminate an alternative, weigh a piece of evidence, or revise a provisional answer — then shows you the decision, the reason, the boundary rule behind it, and what would have to change for the answer to differ.

The Case Lab asks you to work through a complete fictional case end to end. The Decision Lab isolates a single differential-reasoning move within a short scenario. Both draw on the same F20-F29 content and feed the same session mastery indicators; neither replaces the other. See also the Case Lab.

The seven reasoning moves

• Select the best-supported category. Choose the category that is best supported by the information given.
• Eliminate an alternative. Identify which competing category can be ruled out first, and why.
• Identify the decisive evidence. Pick out the single piece of information doing the most discriminating work.
• Identify contradicting evidence. Spot the statement that weakens an otherwise well-supported classification.
• Choose the next information to obtain. Decide what single piece of missing information would most improve confidence.
• Recognise insufficient information. Notice when the available information does not yet support any specific category.
• Revise a provisional answer. Reconsider an initial classification once new information changes the picture.

Items

Category All categories F99 — Mental disorder, not otherwise specified

Reasoning move All moves Select the best-supported category Eliminate an alternative Identify the decisive evidence Identify contradicting evidence Choose the next information to obtain Recognise insufficient information Revise a provisional answer

Difficulty Any difficulty Foundation Developing Boundary Transfer

Apply filters Clear filters Give me a reasoning challenge

1 of 1 items shown

• F99 A short note that already says enough

  Eliminate an alternative · Difficulty: Developing

All items are fictional educational scenarios. See About and Safety.