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After the basics · Worked guides

Jev hierarchical classification: paths, alternatives, and parent fallback

Classify tutorials with a versioned taxonomy, greedy search, limited beam exploration, and coarse-label fallback.

Source checked 2026-10-0217 minutes
What you will build

Track node decisions and retain a reliable parent when a leaf is uncertain.

Before you start · Jev confidence: thresholds, review, and failures

Design it step by step

01

Check the taxonomy assumption

Invented tree: development→API/data→first call/extraction. Give nodes stable IDs and definitions. Truly multi-topic documents may need a primary class plus tags instead of a forced single path.

02

Choose among direct children

Provide source text and the current path. Choice compares the direct children with an uncertainty outcome. Keep full distributions; language is not topic.

03

See how greedy errors become irreversible

Invented root probabilities 0.52 versus 0.48 leave little separation. Greedy search keeps one path and may never reach the correct data/extraction branch. It saves exploration but loses alternatives.

04

Keep bounded alternatives when useful

The official recipe explores K paths with beam search. Test a budget such as K=2 rather than assuming improvement. State the path-scoring and length-normalization rules; a heuristic score is not global correctness probability.

05

Stop at a reliable parent if needed

Return a broad class with unresolved refinement. Log node decisions, model and taxonomy versions, and error locations. Replay fixed tests after tree changes and handle unknown topics explicitly.

Worked example · Invented by this site

ObservationJudgmentApplication action
Root 0.52/0.48; deeper extraction evidenceEarly preference is weakKeep two paths if budget permits
Clear parent, close leavesOnly the parent is establishedReturn parent with review
Two genuine topicsSingle-label assumption failsSeparate primary class and tags

A copyable design draft

Original examples. JSON illustrates request or input structure; Python calculates invented scores without an API call. Verify current interfaces and task policy before integrating.

# Invented taxonomy input; no model calls.
{
  "taxonomy_version": "tutorial-v1",
  "node_id": "development",
  "children": {"api": "API integration", "data": "Data processing"},
  "fallback": "development:needs_review",
  "exploration_budget": {"max_paths": 2, "max_depth": 3}
}
Design a decision

Common mistakes

  1. Assuming a local maximum is a global optimum.
  2. Calling path scores calibrated probabilities.
  3. Changing taxonomy without versions.

TRY / THINK / COMPARE

Think first, then compare

The parent is clear but two leaves tie. Force a leaf?

Show explanation

No. Keep the parent and review or obtain context if a leaf is required.

Before handing it over

  • Stable node IDs and definitions.
  • Distributions and paths logged.
  • Budget, unknowns, and parent fallback defined.
  • Tree updates replay fixed cases.

Common questions

Is beam always better?

No. Compare accuracy and cost on the same cases.

Is a product of edge scores confidence?

No. Path heuristics differ from answer confidence.

Sources and further reading

Inspired by official patterns and Datawhale practice topics. Explanations, examples, and exercises are independently written. These are teaching designs, not live API runs or benchmarks.