An introduction to CHILDES Rianne Schippers

Outline What is CHILDES? Where do you find CHILDES? Why would you use CHILDES? How do you use CHILDES?

What is CHILDES? Child Language Data Exchange System Brain MacWhinney Online database of first and second language acquisition in children. –Written transcripts –Audio –Video Also contains data from not typically developing children.

What is CHILDES? Recorded, natural speech. –Recorded in home setting –Recorded at regular intervals –Longitudinal data Typological variation. –Germanic –Romance –Slavic –Asian

Where is CHILDES? Link: “Databases”, i.e. the datasets. “Database manual” describing each dataset. Programs you can use to browse the databases Manuals that explain how to use the programs

Why use CHILDES? Answer questions about language acquisition Experimental studies –Does child at age X know Y? –Do 3-year-olds know passives? –Do 2-year-olds know inflectional morphology? –What interpretation do children at age X assign to Y? –Do 4-year-olds understand binding? –Do 5-year-olds understand scope freezing?

Why use CHILDES? Questions experiments cannot easily answer: –Role played by input –Order of acquisition –Manner of acquisition –Causality Longitudinal study Big, universal questions –Lexical categories –Inflectional morphology –Argument structure

Why use CHILDES? Does the interaction between language type and pronoun omission match the predictions of parameter- setting models? Are children with Down syndrome responsive to maternal requests? How do children first learn mental state verbs such as “remember” or “know”?

Why use CHILDES? Smaller, language specific questions –Verb second –Subjects (EPP) –Particle verbs Comparative studies –Acquisition of determiners Exploration –Mean Length of Utterance, frequencies

How to use CHILDES? Download and install the dataset(s) you are interested in. The “database manual” describes Language Age(s) Number of children Download and install CLAN ( Computerized Language Analysis): –A search and statistics engine for CHILDES. OR use the NLTK’s CHILDES module.

How to use CHILDES? All files are transcribed in CHAT format –Codes for the Human Analysis of Transcripts Format –Files start information about participants and setting –The rest of the file contains *-tiers and %-tiers –*-tiers: specify the speaker (*CHI = child) –%-tiers: are related to the previous *-tier and give extralinguistic information

How to use CHILDES? %-tiers are also used for coding %pho for phonology %mor for morphology *CHI:I have a ball %mor:PRO|I&1S V|have-PRES DET|a&INDEF N|ball %syn for syntax

How to use CHILDES? Some more annotations #unfilled pause between words 6schwa &phonological fragment xxxunintelligible speech [/]retracing without correction, e.g..: then [/] then [//] retracing, with correction, e.g.: then [//] but ["] quotation mark, used when the child literally repeats something All notation can be found in the CHAT manual

How to use CHILDES? Go to the command window Every search starts with a command –kwal: word search –combo: combined search for 2 or more words –freq: frequency counts –mlu: mlu counts A command is followed by search parameters

How to use CHILDES? Some standard CLAN parameters +tselects the utterances of a specified speaker +sselects a word to be searched +uspecifies that all search results are stored in one file +rdeals with the treatment of material between parentheses +f output is stored in the (specified) file(s) Not all commands have the same search parameters –Type the command in the command window and hit enter

How to use CHILDES? Searching with kwal –Speaker(s) –Word –File(s) Command must come first, the order in which the search parameters are given is irrelevant Every search parameter and the command must be separated from each other by a space

How to use CHILDES? Setting the speaker parameter –Identify the speaker(s) +t = look for that specific speaker -t = look for everyone but that specific speaker We are interested in the child –command parameter-speaker-child kwal +t*CHI

How to use CHILDES? Setting the word parameter –Decide what word you want to look for +s = look for that specific word -s = look for everything except that specific word Let’s say we want to know whether the child has used the auxiliary ‘want’. –command speaker parameter-word-want kwal +t*CHI +s”want”

How to use CHILDES? Specifying the file Two ways: –Using the ‘file in’ button –Specifying the file in the command line Let’s say we want to start our search in file sarah023.cha –Command speaker word file kwal +t*CHI +s”want” sarah023.cha

How to use CHILDES? Exercise: –Discover whether the mother uses the auxiliary ‘want’ in file sarah023.cha

How to use CHILDES? Exercise: –Discover whether the mother uses the auxiliary ‘want’ in file sarah023.cha Steps to take: –Determine the command –Identify the speaker –Decide on the word –Specify the file

How to use CHILDES? Exercise: –Discover whether the mother uses the auxiliary ‘want’ in file sarah023.cha Steps to take: –Determine the command –Identify the speaker –Decide on the word –Specify the file kwal +t*MOT +s”want” sarah023.cha

How to use CHILDES? Searching for several words –Make a list in.txt format –Enter the list as the word you are looking for For example: –A list with all auxiliaries –Named auxiliary.txt –Parameter: kwal +t*CHI sarah023.cha

How to use CHILDES? Output screen is limited Store the data in a separate file –Parameter: +f –File name has three letters –For example: aux Command speaker word parameter-store-filename file kwal +t*CHI +s”want” +faux sarah023.cha

How to use CHILDES? Retype the command: kwal +t*CHI +s”want” sarah023.cha Notice: some material is in between brackets *CHI: wan(t) do (a)gain What does this mean? –Child actually said ‘wan’ instead of ‘want’. CLAN will standardly include the material in between brackets. –CLAN will look for ‘want’

How to use CHILDES? What does this mean? –A search for ‘want’ will give you both ‘wan(t)’ and ‘want’. Control whether the search includes material in between brackets. +r parameter +r1 = default, include material in brackets +r2 = exclude material in brackets +r5 = exclude rephrased material

How to use CHILDES? Try out: kwal +t*CHI +s”want” +r2 sarah023.cha +r5 allows for exclusion of rephrased material What is rephrased material? *CHI: I wanna [: want to] eat cereal In the default setting, CLAN will look for rephrased material The +r5 option allows you to look for ‘wanna’.

How to use CHILDES? Searching with both +s and –s CLAN only allows you to specify either +s or -s Imagine you want to look for all the conjugations of one verb, but are not interested in any other, identical words For example: all the verbal forms of ‘go’ First of all: wild card –Wild card *, allows you to look for anything

How to use CHILDES? Adding the * to the word search +s”go*” Words that this search will find are: go, gone, goes, going But also words such as: got, good, goat, god etc. Ideally, you want to specify both +s and –s Piping option

How to use CHILDES? Piping: the second command operates on the output of the first command First command: look for ‘go*’  second command: exclude ‘good’, ‘got’, etc. In order for the second command to be able to operate on the first, the first command must give an output in CHAT format +d option

How to use CHILDES? First command: –Look for ‘go*’ –For the speaker *CHI –Output must be in CHAT format –In file sarah040.cha kwal +t*CHI +s”go*” +d sarah040.cha Second command: exclude ‘got’ kwal –s”got”

How to use CHILDES? Piping the first and the second command first command piping-operation second command kwal +t*CHI +s”go*” +d sarah040.cha | kwal –s”got”

How to use CHILDES? Looking for more than one word at a time Searching with combo –Speaker(s) –Words –File(s) Boolean operators: ^ = immediately followed by * = any character + = or ! = not

How to use CHILDES? Setting the speaker parameter combo +t*CHI Setting the word parameter –Let’s look for the combination of ‘want’ and ‘to’ –‘want’ immediately followed by ‘to’ combo +t*CHI +s”want^to”

How to use CHILDES? Specifying the file –Let’s look in file sarah034.cha combo +t*CHI +s”want^to” sarah034.cha Combo looks for the words in sequence by default The +x parameter allows you to look for two or more words in any order

How to use CHILDES? Searching for ‘want’ directly followed by ‘to’ without +x only gives ‘want to’ combo +t*CHI +s”want^to” sarah034.cha Searching for ‘want’ directly followed by ‘to’ with +x gives both ‘want to’ and ‘to want’ combo +t*CHI +s”want^to” +x sarah034.cha

Pitfalls and limitations Cannot test for acceptability or ungrammaticality Be aware of: –Routines –Imitations –Speech errors –Mistranscriptions

Protocol CHILDES transcripts were collected with great effort and are now freely available. In return for using them, you reward the creators with citations. Cite latest copy of MacWhinney’s book: MacWhinney, B. (2000). The CHILDES project: Tools for analyzing talk. Third Edition. Mahwah, NJ: Lawrence Erlbaum Associates. Cite the publication selected by the creator(s) of the database(s) you have used. –References can be found in the ‘database manuals’ on the site