Pelorus Space is an open RAG test dataset from Pelorus Query, shipped in RAG Connector.
How RAG fails · Pelorus Space

Eighteen ways to give a passenger the wrong answer.

A retrieval system rarely fails with a blank. It finds something relevant, and the generator writes a fluent, confident answer from it. Each question below has a tempting wrong answer built into the corpus, most of them one plausible retrieval away.

Type names follow the testset-kit taxonomy used by RAGauge and the Pelorus Query question sets: ragauge-rag-challenges version 0.2, eighteen types. Older question sets call BOUNDARY by its earlier name, CONTIG. The wrong answers are illustrative. Each is what a pipeline says when it trusts the chunk that ranked first.

01
CONF · conflict_reconciliation

Two documents disagree

Both chunks match the question well. The pipeline picks whichever ranked first and never mentions the other.

How long before the Olympus Mons Caldera Rim hike do I have to pass the Olympus Fitness Test?
At least 24 hours before the excursion.
The documents disagree. The Caldera Rim flyer says 24 hours. The Mars guide, the itinerary guides, the medical guide and the FAQ all say 48 hours, which is why the itineraries put the test on Day 8 for a Day 10 hike. Nothing reconciles them. A trustworthy answer points out the conflict.

Why it happens: ranking is not reconciliation. The flyer is short and entirely about the hike, so it often ranks first; nothing in top-k retrieval notices that a lower-ranked chunk says something else.

02
DISAM · distractor_disambiguation

A near-twin answers instead

Two things with the same name, and different rules.

I've booked a Pathfinder suite. Does that get me early access to book the Venus gondola?
Yes. Pathfinder guests get a 48-hour priority booking window for the Gondola Descent.
No. The 48-hour priority window belongs to the Pathfinder loyalty tier, earned with Orbital Points. Pathfinder cabin class gives no booking advantage: the gondola is an add-on at every class.

Why it happens: the cabin classes and the loyalty tiers share their names, Pioneer, Navigator and Pathfinder. To an embedding model "Pathfinder priority" is one idea, so a chunk about cabin benefits ranks as well as the one about the tier.

03
AMBIG · ambiguity_clarification

The question means two things

The honest answer is a clarifying question, or both answers clearly labelled.

Can I pay for drinks on board with my Orbital balance?
Yes. Your Orbital balance can be applied to your onboard account, which bar purchases are charged to.
It depends which balance is meant. Orbital Credits, the stored-value payment account, can settle the onboard account. Orbital Points, the loyalty currency, cannot: they are not a payment method. The answer should ask, or give both.

Why it happens: the documents define the two as "distinct in every way", but a passenger calls either one "my Orbital balance". A pipeline that retrieves only one of them answers for that one, with confidence.

04
TABLE · structured_table

The wrong row

The answer is a single table cell, and the row next to it holds a different number.

Can my 12-year-old do the glass floor tour at Venus?
No. The minimum age is 16 and is firm, with no parental consent override.
Yes. The Glass Floor Tour minimum age is 8. The 16 belongs to the Gondola Descent, the very next row of the same table.

Why it happens: a chunk that cuts through a table, or a model reading pipe-delimited rows, easily attaches a value to the wrong row. It is worse when the neighbouring row is on the same topic and both are marked firm.

05
NEG · negation_exclusion

"No" retrieved as "yes"

The document says something is not available. Embeddings barely register the "not".

Can I do an EVA at Enceladus?
Yes. Complete EVA suit orientation before your first surface excursion, and your guide will brief you at the airlock.
No. There is no EVA and no surface access at Enceladus. Planetary protection protocols set a 25-kilometre approach altitude, and the four-hour flyover is watched from the observation deck.

Why it happens: "No EVA, no surface access" sits close to every EVA procedure in embedding space. If the procedure chunks outrank the exclusion, the generator fills in a helpful, wrong yes.

06
COND · conditional_branching

The rule has an exception

The general rule is easy to find. The branch that applies to this passenger is somewhere else.

If I cancel my voyage ten days before it leaves, how much do I get back?
A full refund. Cancellations within 14 days receive a full refund with no administrative fee.
50 percent, if the booking is more than 14 days old. The free window runs 14 days from the date of booking, not before departure. Ten days before departure falls in the 7-to-29-day band: a 50 percent fee.

Why it happens: the free-cancellation rule is the best match for "how much do I get back", and it promises a full refund with total confidence. Only two words in it, "of booking", say which clock the 14 days run on.

07
HOP · multi_hop

The answer takes a chain

Each link is in a different place, and the question names none of them.

If I miss the ship's departure from the stop where you do The Leap, how much will the Extraction Coverage add-on pay toward a charter?
Up to 2 times the original voyage package price.
Up to 4 times. The Leap is at Ceres Waystation. Ceres is an outer system stop, and the Extraction Coverage cap there is 4× the package price. The 2× cap applies at inner system stops.

Why it happens: the question never says "Ceres". The extraction terms list both caps by stop, and without the flyer that puts The Leap at Ceres the model has to guess which row applies. The first row, the inner system cap, is the easy pick.

08
SYN · multi_document_synthesis

The answer is in pieces

Every piece is correct. Returned alone, any one of them is incomplete.

My launch was scrubbed. What am I entitled to?
A full refund of all amounts paid, with no cancellation fee.
A full refund or a voyage credit worth 110 percent, valid for 24 months. You must choose within 14 days, or the refund is processed automatically. Scrub passengers get a 14-day priority rebooking window, pending Orbital Points are held 90 days for a rebooking, and refund timing depends on how you paid.

Why it happens: top-k returns the best-matching paragraph. The credit option, the deadline, rebooking priority, the Points hold and refund timing sit in other sections and another document, and each scores lower on its own.

09
AGG · aggregation_comparison

The answer has to be worked out

Both values are found separately. The comparison the question asks for is written nowhere.

In the worst case, how many more minutes does a one-way message to Earth take from Saturn than from the Mars leg?
124 minutes. A reply from Saturn takes up to 168 minutes, against up to 44 from Mars.
62 minutes. The one-way delay tops out at 84 minutes at Saturn and 22 minutes on the Mars leg. The 168 and 44 printed beside them are round-trip reply times, which double the difference.

Why it happens: the answer is a subtraction that appears in no document, so retrieval can only supply its inputs. The same paragraphs give a round-trip figure next to each one-way figure, and a generator that takes the wrong pair still does the arithmetic perfectly.

10
IMP · implicit_inference

No sentence says it

Every fact the answer needs is stated. The conclusion is not stated anywhere.

At The Aphrodite our departure window opens at 4 pm. If I join a Glass Floor Tour group that starts at 2 pm, will I get the full tour?
Yes. The tour lasts 90 minutes, so it ends at 3:30, in time for the 30-minute muster at Docking Pier 1.
No. The final Glass Floor Tour group must exit 60 minutes before the departure window, so by 3 pm. The tour lasts 90 minutes, and a group starting at 2 pm gets about 60 of them.

Why it happens: no passage says a 2 pm group is cut short. The answer comes from putting the exit rule beside the tour length, and the deadline that sits closest to the question, the 30-minute muster, is the wrong one to measure against.

11
DATE · temporal_reasoning

The answer needs arithmetic

The rule is retrieved correctly. Applying it takes a date calculation the model has to actually do.

My doctor signed my clearance on 20 November and my voyage departs on 24 February. Is the clearance still valid?
Yes. Clearance lasts about three months, and 20 November to 24 February is roughly three months.
No. Clearance is valid for 90 calendar days from sign-off, which ends on 18 February. The departure is 96 days after sign-off. The medical guide warns about exactly this case: 90 days is not three months.

Why it happens: models round durations into familiar units, and "90 days" becomes "three months" before any counting happens.

12
QUAL · qualifying_context

Right number, missing caveat

The answer is complete, fluent and wrong, rather than visibly incomplete.

How much is the nightly service charge for a Navigator cabin?
USD 22 per passenger per night, every night of the voyage.
USD 22 on the Outer Reaches Tour. The only charges sheet in the corpus covers the ORT. The Inner Planets Survey and the Grand Solar Tour are charged on their own sheets, and the figures are not transferable.

Why it happens: the sheet states its scope at the top, several chunks away from the price table. The chunk with the number has no itinerary in it, so a passenger on another voyage gets a confident, wrong figure.

13
KW · exact_lexical

An acronym the embedding doesn't know

Dense retrieval is good at meaning and poor at rare exact strings.

Under the OSTC 2038, which ships are obliged to take me on board if I'm stranded?
If you miss your departure, contact the expedition coordinator. Your travel insurance may cover an extraction flight.
The Outer Space Transport Compact requires any commercial vessel in cislunar space or beyond to accept a documented distressed traveller if it has life-support capacity, including the mining transports. It is passage, not service, and the passage cannot be charged.

Why it happens: a four-letter acronym carries almost no meaning for an embedding model, so "stranded" pulls in the missed-departure passages instead. Keyword or hybrid retrieval finds the right one immediately.

14
PARA · semantic_paraphrase

Same meaning, different words

The question and the document say the same thing with substantially different wording.

Where do I have to put pen to paper on the release form for the big untethered hop?
At Ceres Waystation, when you check in for the jump.
At Moon Base 7 only, with the expedition coordinator during the Day 3 layover, before the vessel leaves for the outer system. The release form is The Leap waiver, and the Ceres team cannot process it: a passenger who arrives without one on file cannot jump.

Why it happens: the question shares no content word with the passage that answers it. "Put pen to paper" is "signed", "release form" is "waiver", and "the big untethered hop" is The Leap. Keyword retrieval has nothing to match, and an embedding model has to know the idiom. A guess lands on Ceres, where the hop happens.

15
CTX · context_conditioning

It depends on the itinerary

The same question has different right answers for different passengers.

What can I do during my time at Moon Base 7?
Tour Tranquility Base, play the Lunar Golf Links, or take the pressurised rover tour.
On the Grand Solar Tour, those excursions, with a layover of about 18 to 24 hours. On the Inner Planets Survey or Outer Reaches Tour, about four hours: vessel transfer and document processing, and no shore excursions.

Why it happens: the excursion descriptions are vivid and specific, so they outrank the dry sentence about layover length. The question never says which itinerary.

16
LIST · list_completeness

Half a list

A list that spans several chunks comes back as whichever items made the top-k.

What rules do visitors have to obey at the Apollo landing site at Tranquility Base?
No flash photography within 50 metres of the perimeter, and no drones in the heritage zone.
Five rules, enforced under OSHPA 2041: no approach within the exclusion boundary; no collection of surface material; no flash photography within 50 metres of the perimeter flagging; no drones within the heritage zone, which extends 2 km beyond the perimeter; and no lasers aimed at any heritage object.

Why it happens: the list crosses a chunk boundary. Nothing tells the generator the list is incomplete, and two rules read like a finished answer.

17
BOUNDARY · boundary_assembly

The cut fell through the answer

The answer is divided across neighbouring chunks of one document, and no single chunk carries it all.

What is the muster deadline at The Aphrodite on Venus, and where do we muster?
60 minutes before departure, at Docking Pier 1, Resort Deck 2.
30 minutes before the departure window opens, at Docking Pier 1, Resort Deck 2: the shortest muster window on the itinerary. The 45, 60 and 90 minutes in the same row are when the pool and sun deck close, when the last glass floor group exits, and the gondola cutoff.

Why it happens: the check-in card's table is cut in two. The Venus row lands in the second chunk, and the header that says which column is the deadline stays in the first. Retrieved alone, the row is a place and four numbers of minutes, with nothing to say which one is the muster.

18
UNANS · unanswerable_abstention

The corpus doesn't say

The right answer is to say so. Nearby numbers make that hard.

How much does the Outer Reaches Tour cost in a Pioneer cabin?
Pioneer is the most affordable class. Expect around USD 180 per kilogram, with shore excursions purchased separately.
The documents don't publish fares, for any itinerary or class. A good answer says that. Pets, smoking, weddings and religious services aren't covered either, and the test sets ask about each.

Why it happens: a retriever always returns its k nearest chunks, even when none is relevant. USD 180 is Pioneer's excess-baggage rate per kilogram, the closest thing to a fare the corpus has.

Why this matters to Pelorus Query

Resolve it once. Serve it every time.

Real traffic keeps returning to the same questions, and the traps above keep firing on each repeat. Pelorus Query builds curated, source-grounded Query Extracts for questions that recur. Once someone has reconciled the fitness-test conflict or added the itinerary caveat to the service charge, every later passenger gets that answer instead of whichever chunk ranked first.

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