--- title: A fair test changes only one thing at a time and keeps everything el… — How scientists find out: naturalists, Darwin, th… · tree and pragmatics description: A fair test changes only one thing at a time and keeps everything else the same, and scientists repeat experiments to check that a result is not luck. Who acts: fair test, scientists, result. A sentence of the lesson «How scientists find out: naturalists, Darwin, the microscope and wildlife filming» --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/biology/264-how-scientists-find-out-naturalists-darwin-the-microscope-and-wildlife-filming/14/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/) / [How scientists find out: naturalists,…](https://md.mova.elamur.ai/free/en/corpora/school/biology/264-how-scientists-find-out-naturalists-darwin-the-microscope-and-wildlife-filming/) / 14 # How scientists find out: naturalists, Darwin, the microscope and wildlife filming, sentence 14 A fair test changes only one thing at a time and keeps everything else the same, and scientists repeat experiments to check that a result is not luck. **Who acts:** fair test, scientists, result · **What happens:** change, keep, repeat, check, not be · **To what, where:** one thing, everything, experiments, luck This is a sentence of the lesson «How scientists find out: naturalists, Darwin, the microscope and wildlife filming» of the biology course of Mova's primary school. The page gives its syntax tree — a dependency tree in the style of Universal Dependencies — and its pragmatics clause by clause: who acts (fair test, scientists, result), what happens, when and where, as Mova's frames read it from the tree. ## The tree {#tree} ```conllu # sent_id = school:biology:264-how-scientists-find-out-naturalists-darwin-the-microscope-and-wildlife-filming.lesson:14 # text = A fair test changes only one thing at a time and keeps everything else the same, and scientists repeat experiments to check that a result is not luck. # source = school lesson (ours) # course = biology # lesson = 264-how-scientists-find-out-naturalists-darwin-the-microscope-and-wildlife-filming.lesson # annotation = Mova annot: Rust (en) → Haiku 5.5 (medium, Batches API) patches; gates UD 2.18; agreed by treeagree rules (Stanza, Trankit, spaCy trf): R5-strong ×2 1 A a DET DT Definite=Ind|PronType=Art 3 det _ _ 2 fair fair ADJ JJ Degree=Pos 3 amod _ _ 3 test test NOUN NN Number=Sing 4 nsubj _ _ 4 changes change VERB VBZ Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin 0 root _ _ 5 only only ADV RB _ 7 advmod _ _ 6 one one NUM CD NumForm=Word|NumType=Card 7 nummod _ _ 7 thing thing NOUN NN Number=Sing 4 obj _ _ 8 at at ADP IN _ 10 case _ _ 9 a a DET DT Definite=Ind|PronType=Art 10 det _ _ 10 time time NOUN NN Number=Sing 7 nmod _ _ 11 and and CCONJ CC _ 12 cc _ _ 12 keeps keep VERB VBZ Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin 4 conj _ _ 13 everything everything PRON NN Number=Sing|PronType=Tot 12 obj _ _ 14 else else ADV RB _ 13 advmod _ _ 15 the the DET DT Definite=Def|PronType=Art 16 det _ _ 16 same same ADJ JJ Degree=Pos 12 xcomp _ Agree=R5-strong|Haiku=13:nmod 17 , , PUNCT , _ 20 punct _ _ 18 and and CCONJ CC _ 20 cc _ _ 19 scientists scientist NOUN NNS Number=Plur 20 nsubj _ _ 20 repeat repeat VERB VBP Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin 4 conj _ _ 21 experiments experiment NOUN NNS Number=Plur 20 obj _ _ 22 to to PART TO _ 23 mark _ _ 23 check check VERB VB VerbForm=Inf 20 advcl _ Agree=R5-strong|Haiku=21:acl 24 that that SCONJ IN _ 29 mark _ _ 25 a a DET DT Definite=Ind|PronType=Art 26 det _ _ 26 result result NOUN NN Number=Sing 29 nsubj _ _ 27 is be AUX VBZ Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin 29 cop _ _ 28 not not PART RB Polarity=Neg 29 advmod _ _ 29 luck luck NOUN NN Number=Sing 23 ccomp _ _ 30 . . PUNCT . _ 4 punct _ _ ``` ## Pragmatics {#pragmatics} No stored speech act for this sentence. | # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 1 | **change** | present | a fair test | one thing | | | at a time | | vn dress-41.1.1-1-1 «NP V NP»: agent=Agent thing=Patient | | 2 | **keep** | present | a fair test *not said here* | everything | | | | same *property* | vn keep-15.2 «NP V NP»: agent=Agent everything=Theme | | 3 | **repeat** | present | scientists | experiments | | | | | vn begin-55.1-1-1 «NP V NP»: agent=Agent experiment=Eventuality | | 4 | **check** | to-infinitive | scientists *not said here* | | | | | | vn assessment-34.1 «NP V NP»: agent=Agent | | 5 | **not** **is a** | present | a result | luck | | | | | tree rules | 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. **Licence: [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/)**, as the whole of Mova corpus 0.4, of which this treebank (the agreed school, `mova-school-agreed-en.conllu`) is part. The lessons were written for Mova's primary school. Sentence `school:biology:264-how-scientists-find-out-naturalists-darwin-the-microscope-and-wildlife-filming.lesson:14`. **The tree:** Mova annot: Rust (en) → Haiku 5.5 (medium, Batches API) patches; gates UD 2.18; agreed by treeagree rules (Stanza, Trankit, spaCy trf): R5-strong ×2. **The frames** are read from the tree by Mova's frames reader (`prag`) when this page is built, the lesson read in order, so a pronoun may be resolved from an earlier sentence. See the [release 0.4](https://md.mova.elamur.ai/free/en/releases/0.4/). - ← previous: [How scientists find out: naturalists,…, 13](https://md.mova.elamur.ai/free/en/corpora/school/biology/264-how-scientists-find-out-naturalists-darwin-the-microscope-and-wildlife-filming/13/) - next →: [How scientists find out: naturalists,…, 15](https://md.mova.elamur.ai/free/en/corpora/school/biology/264-how-scientists-find-out-naturalists-darwin-the-microscope-and-wildlife-filming/15/) - ↑ back to [the lesson](https://md.mova.elamur.ai/free/en/corpora/school/biology/264-how-scientists-find-out-naturalists-darwin-the-microscope-and-wildlife-filming/)