Triple

T269518
Position Surface form Disambiguated ID Type / Status
Subject MBTA Green Line D branch E5598 entity
Predicate usesRollingStock P5426 FINISHED
Object MBTA Type 9 Light Rail Vehicle
The MBTA Type 9 Light Rail Vehicle is a modern, low-floor streetcar used on Boston’s Green Line that features improved accessibility, passenger comfort, and energy efficiency compared to earlier MBTA light rail fleets.
 E35647 NE FINISHED

How this triple was built (4 steps)

Every LLM step that produced this triple, in pipeline order — named-entity classification, the disambiguation choices (the exact options shown, with the pick highlighted), and the generated description. The batch + timestamp of each is in the Provenance table below.

NER Named-entity recognition gpt-5-mini
Instruction
Given a phrase, classify it is english named entity (e.g., persons, organizations, works of art) in Latin script, or not (e.g., literals, dates, URLs, verbose phrases). For disambiguation, the statement where the phrase occurs as object is also given. Please return a JSON object with `phrase` (string, the phrase being analyzed) and `is_ne` (boolean, indicating whether the phrase is a Named Entity).
Input
Phrase: MBTA Type 9 Light Rail Vehicle | Statement: [MBTA Green Line D branch, usesRollingStock, MBTA Type 9 Light Rail Vehicle]
NED1 Entity disambiguation (via context triple) gpt-5-mini-2025-08-07 
Target entity: MBTA Type 9 Light Rail Vehicle
Context triple: [MBTA Green Line D branch, usesRollingStock, MBTA Type 9 Light Rail Vehicle]
  • A. MBTA Type 8 Light Rail Vehicle
    The MBTA Type 8 Light Rail Vehicle is a low-floor, articulated streetcar used on Boston’s Green Line, designed to improve accessibility and passenger capacity on the system’s light rail routes.
  • B. MBTA Type 7 Light Rail Vehicle
    The MBTA Type 7 Light Rail Vehicle is a high-floor, articulated streetcar used on Boston’s Green Line, known for its distinctive design and role as one of the system’s primary light rail fleets.
  • C. Mark VI monorail trains
    Mark VI monorail trains are a fleet of streamlined, automated monorail vehicles introduced in the late 1980s that serve as the primary passenger trains for the Walt Disney World Resort’s elevated transit system.
  • D. M9 electric multiple unit
    The M9 electric multiple unit is a modern commuter rail train used by the Long Island Rail Road, designed to replace older fleets with improved performance, safety, and passenger amenities.
  • E. Portland Streetcar
    Portland Streetcar is a modern urban streetcar transit system serving central Portland, Oregon, connecting key neighborhoods, employment centers, and educational institutions.
  • F. None of above. chosen
  • G. Unsure - the case is ambiguous/there is not enough information to decide.
NEDg Description generation gpt-5.1
Instruction
Generate a one-sentence description of the target entity. 
You are given a context triple in the form (subject, predicate, object), where the object is the target entity. 
# Instructions
Use the triple to infer relevant information about the entity. Describe the entity based on what is most defining, well-known. 
Avoid repeating the information from the triple, unless really essential.
# Response Format
Return only the sentence: "Description: [one-sentence description of the target entity]"
Input
Entity: MBTA Type 9 Light Rail Vehicle
Triple: [MBTA Green Line D branch, usesRollingStock, MBTA Type 9 Light Rail Vehicle]
Generated description
The MBTA Type 9 Light Rail Vehicle is a modern, low-floor streetcar used on Boston’s Green Line that features improved accessibility, passenger comfort, and energy efficiency compared to earlier MBTA light rail fleets.
NED2 Entity disambiguation (via description) gpt-5-mini-2025-08-07 
Target entity: MBTA Type 9 Light Rail Vehicle
Target entity description: The MBTA Type 9 Light Rail Vehicle is a modern, low-floor streetcar used on Boston’s Green Line that features improved accessibility, passenger comfort, and energy efficiency compared to earlier MBTA light rail fleets.
  • A. MBTA Type 8 Light Rail Vehicle
    The MBTA Type 8 Light Rail Vehicle is a low-floor, articulated streetcar used on Boston’s Green Line, designed to improve accessibility and passenger capacity on the system’s light rail routes.
  • B. MBTA Type 7 Light Rail Vehicle
    The MBTA Type 7 Light Rail Vehicle is a high-floor, articulated streetcar used on Boston’s Green Line, known for its distinctive design and role as one of the system’s primary light rail fleets.
  • C. Mark VI monorail trains
    Mark VI monorail trains are a fleet of streamlined, automated monorail vehicles introduced in the late 1980s that serve as the primary passenger trains for the Walt Disney World Resort’s elevated transit system.
  • D. M9 electric multiple unit
    The M9 electric multiple unit is a modern commuter rail train used by the Long Island Rail Road, designed to replace older fleets with improved performance, safety, and passenger amenities.
  • E. Portland Streetcar
    Portland Streetcar is a modern urban streetcar transit system serving central Portland, Oregon, connecting key neighborhoods, employment centers, and educational institutions.
  • F. None of above. chosen

Provenance (5 batches)

The batch behind each pipeline step, in order, with when it ran. Timestamps are batch-level — stages were processed in waves, so the object chain (NER → NED1 → NEDg → NED2) reads in order, but predicate / elicitation batches can sit in a different wave.

Step Stage Batch ID Status When
creating Elicitation batch_69a25853594c8190b05ec3a586ec88bf completed Feb. 28, 2026, 2:52 a.m.
NER Named-entity recognition batch_69a25db00ed48190be6f598807265356 completed Feb. 28, 2026, 3:14 a.m.
NED1 Entity disambiguation (via context triple) batch_69a3914eba9081908cdef8b719c9b20b completed March 1, 2026, 1:07 a.m.
NEDg Description generation batch_69a391888bbc81908d86e3a1f15cb84e completed March 1, 2026, 1:08 a.m.
NED2 Entity disambiguation (via description) batch_69a3921fc8c8819084d2dab21012e53a completed March 1, 2026, 1:10 a.m.
Created at: Feb. 28, 2026, 2:57 a.m.