Exam question 2 · Loot boxes and the surprise trap

Given that the probability of obtaining a rare item from a single box is one per cent, select the statement consistent with the established facts concerning one hundred successive boxes.

Mova's choice: option 2 · The right answer: option 3 · wrong ✗ · Who acts: you, probability, established facts · What happens: give, obtain, be, select, establish, concern · To what, where: rare item, single box, one per cent, statement, hundred successive boxes

This is exam question 2 of lesson 413 «Loot boxes and the surprise trap» of the everyday course of Mova's primary school, asked in stiff, formal language. The page gives the question's syntax tree — a dependency tree in the style of Universal Dependencies — and its pragmatics clause by clause, then the 4 options as the student saw them, each with its tree and pragmatics. Every text is parsed by Mova itself. How the student answered it, with the score of every option and why: the test at school.

The question

The words, one row each (CoNLL-U)

#	word	lemma	UPOS	features	head	relation
1	Given	give	VERB	Tense=Past VerbForm=Part Voice=Pass	19 select	advcl
2	that	that	SCONJ	_	17 cent	mark
3	the	the	DET	Definite=Def PronType=Art	4 probability	det
4	probability	probability	NOUN	Number=Sing	17 cent	nsubj
5	of	of	SCONJ	_	6 obtaining	mark
6	obtaining	obtain	VERB	VerbForm=Ger	4 probability	acl
7	a	a	DET	Definite=Ind PronType=Art	9 item	det
8	rare	rare	ADJ	Degree=Pos	9 item	amod
9	item	item	NOUN	Number=Sing	6 obtaining	obj
10	from	from	ADP	_	13 box	case
11	a	a	DET	Definite=Ind PronType=Art	13 box	det
12	single	single	ADJ	Degree=Pos	13 box	amod
13	box	box	NOUN	Number=Sing	9 item	nmod
14	is	be	AUX	Mood=Ind Number=Sing Person=3 Tense=Pres VerbForm=Fin	17 cent	cop
15	one	one	NUM	NumForm=Word NumType=Card	17 cent	nummod
16	per	per	NOUN	Number=Sing	17 cent	compound
17	cent	cent	NOUN	Number=Sing	1 Given	advcl
18	,	,	PUNCT	_	1 Given	punct
19	select	select	VERB	Mood=Imp VerbForm=Fin	root	root
20	the	the	DET	Definite=Def PronType=Art	21 statement	det
21	statement	statement	NOUN	Number=Sing	19 select	obj
22	consistent	consistent	ADJ	Degree=Pos	19 select	xcomp
23	with	with	ADP	_	26 facts	case
24	the	the	DET	Definite=Def PronType=Art	26 facts	det
25	established	establish	VERB	Tense=Past VerbForm=Part Voice=Pass	26 facts	amod
26	facts	fact	NOUN	Number=Plur	22 consistent	obl
27	concerning	concern	VERB	VerbForm=Ger	26 facts	acl
28	one	one	NUM	NumForm=Word NumType=Card	29 hundred	compound
29	hundred	hundred	NUM	NumForm=Word NumType=Card	31 boxes	nummod
30	successive	successive	ADJ	Degree=Pos	31 boxes	amod
31	boxes	box	NOUN	Number=Plur	27 concerning	obj
32	.	.	PUNCT	_	19 select	punct

#	verb	tense, mood	who	what, whom	where	other	roles by
1	give	participle	you not said here				vn break_down-45.8 «NP V»: agent=Patient
2	obtain	gerund	the probability not said here	a rare item	a single box		vn obtain-13.5.2-1 «NP V NP PP.source»: agent=Agent item=Theme from box=Source
3	is a	present	the probability	one per cent			tree rules
4	select	imperative	you not said here	the statement		consistent property	vn obtain-13.5.2 «NP V NP»: agent=Agent statement=Theme
5	establish	participle					vn indicate-78-1-1 «NP V NP to be NP»: agent=Pivot
6	concern	gerund	the established facts not said here	hundred successive boxes			vn amuse-31.1 «NP V NP»: agent=Stimulus box=Experiencer

One row per clause the reader finds. «not said here»: a role filled from the clause above. «roles by»: a VerbNet class and frame when one fits the verb, else the reader's rules on the tree.

The options

Option 1

The probability increases with each unsuccessful purchase until a rare item appears

The words, one row each (CoNLL-U)

#	word	lemma	UPOS	features	head	relation
1	The	the	DET	Definite=Def PronType=Art	2 probability	det
2	probability	probability	NOUN	Number=Sing	3 increases	nsubj
3	increases	increase	VERB	Mood=Ind Number=Sing Person=3 Tense=Pres VerbForm=Fin	root	root
4	with	with	ADP	_	7 purchase	case
5	each	each	DET	PronType=Tot	7 purchase	det
6	unsuccessful	unsuccessful	ADJ	Degree=Pos	7 purchase	amod
7	purchase	purchase	NOUN	Number=Sing	3 increases	obl
8	until	until	SCONJ	_	12 appears	mark
9	a	a	DET	Definite=Ind PronType=Art	11 item	det
10	rare	rare	ADJ	Degree=Pos	11 item	amod
11	item	item	NOUN	Number=Sing	12 appears	nsubj
12	appears	appear	VERB	Mood=Ind Number=Sing Person=3 Tense=Pres VerbForm=Fin	3 increases	advcl

#	verb	tense, mood	who	what, whom	to whom	where	when	other	roles by
1	increase	present	the probability					with each unsuccessful purchase	vn caused_calibratable_cos-45.6.2-1 «NP V ADV-Middle»: agent=Patient
2	appear	present	a rare item						vn appear-48.1.1 «NP V»: agent=Theme

Option 2 · ← Mova's choice

A rare item is guaranteed within the first ten boxes

The words, one row each (CoNLL-U)

#	word	lemma	UPOS	features	head	relation
1	A	a	DET	Definite=Ind PronType=Art	3 item	det
2	rare	rare	ADJ	Degree=Pos	3 item	amod
3	item	item	NOUN	Number=Sing	5 guaranteed	nsubj:pass
4	is	be	AUX	Mood=Ind Number=Sing Person=3 Tense=Pres VerbForm=Fin	5 guaranteed	aux:pass
5	guaranteed	guarantee	VERB	Tense=Past VerbForm=Part Voice=Pass	root	root
6	within	within	ADP	_	10 boxes	case
7	the	the	DET	Definite=Def PronType=Art	10 boxes	det
8	first	first	ADJ	Degree=Pos NumForm=Word NumType=Ord	10 boxes	amod
9	ten	ten	NUM	NumForm=Word NumType=Card	10 boxes	nummod
10	boxes	box	NOUN	Number=Plur	5 guaranteed	obl

#	verb	tense, mood	who	what, whom	to whom	where	when	other	roles by
1	guarantee	present · passive		a rare item				within the first ten boxes	vn ensure-99 «NP V NP»: subject=Theme

Option 3 · ✓ the right answer

A rare item is not guaranteed, and roughly one purchaser in three obtains none

The tree, 14 words

The words, one row each (CoNLL-U)

#	word	lemma	UPOS	features	head	relation
1	A	a	DET	Definite=Ind PronType=Art	3 item	det
2	rare	rare	ADJ	Degree=Pos	3 item	amod
3	item	item	NOUN	Number=Sing	6 guaranteed	nsubj:pass
4	is	be	AUX	Mood=Ind Number=Sing Person=3 Tense=Pres VerbForm=Fin	6 guaranteed	aux:pass
5	not	not	PART	Polarity=Neg	6 guaranteed	advmod
6	guaranteed	guarantee	VERB	Tense=Past VerbForm=Part Voice=Pass	root	root
7	,	,	PUNCT	_	14 obtains	punct
8	and	and	CCONJ	_	14 obtains	cc
9	roughly	roughly	ADV	_	10 one	advmod
10	one	one	NUM	NumForm=Word NumType=Card	11 purchaser	nummod
11	purchaser	purchaser	NOUN	Number=Sing	14 obtains	nsubj
12	in	in	ADP	_	13 three	case
13	three	three	NUM	NumForm=Word NumType=Card	11 purchaser	nmod
14	obtains	obtain	VERB	Mood=Ind Number=Sing Person=3 Tense=Pres VerbForm=Fin	6 guaranteed	conj
15	none	none	PRON	PronType=Neg	14 obtains	obj

#	verb	tense, mood	who	what, whom	to whom	where	when	other	roles by
1	not guarantee	present · passive		a rare item					vn ensure-99 «NP V NP»: subject=Theme
2	obtain	present	one purchaser in three	none					vn obtain-13.5.2-1 «NP.asset V NP»: agent=Asset none=Theme

Option 4

A rare item is guaranteed upon the hundredth box, though not before it

The words, one row each (CoNLL-U)

#	word	lemma	UPOS	features	head	relation
1	A	a	DET	Definite=Ind PronType=Art	3 item	det
2	rare	rare	ADJ	Degree=Pos	3 item	amod
3	item	item	NOUN	Number=Sing	5 guaranteed	nsubj:pass
4	is	be	AUX	Mood=Ind Number=Sing Person=3 Tense=Pres VerbForm=Fin	5 guaranteed	aux:pass
5	guaranteed	guarantee	VERB	Tense=Past VerbForm=Part Voice=Pass	root	root
6	upon	upon	ADP	_	9 box	case
7	the	the	DET	Definite=Def PronType=Art	9 box	det
8	hundredth	hundredth	ADJ	Degree=Pos	9 box	amod
9	box	box	NOUN	Number=Sing	5 guaranteed	obl
10	,	,	PUNCT	_	13 before	punct
11	though	though	SCONJ	_	13 before	mark
12	not	not	PART	Polarity=Neg	13 before	advmod
13	before	before	SCONJ	_	5 guaranteed	advmod
14	it	it	PRON	Case=Acc Gender=Neut Number=Sing Person=3 PronType=Prs	13 before	obl

#	verb	tense, mood	who	what, whom	to whom	where	when	other	roles by
1	guarantee	present · passive		a rare item				upon the hundredth box	vn ensure-99 «NP V NP»: subject=Theme

Text: the tests of Mova's primary school, written for Mova (world/data/school/), as the course runner gave them to the student. Trees: Mova's own parse — the en model on the CPU, when the site is built — not checked by a teacher; they may be wrong. Frames: Mova's frames reader (prag), each text read on its own. Elamur Cosmic License.

This page in Markdown → https://md.mova.elamur.ai/free/en/corpora/questions/everyday/413-loot-boxes-and-the-surprise-trap/e2/