CG3 in dialogue systems - Vasta and Sahka

Lene Antonsen, Biret Ánne Bals Baal

Saara Huhmarniemi, Trond Trosterud

http://giellatekno.uit.no/oahpa/

30. oktober 2008

1

http://victorio.uit.no/oahpa/morfa/

2

Pedagogical programs for learning sámi with QA - coming

Vasta: The program generates questions, the student can answerquite freely - with grammatical feedback

Sahka: A written dialogue between the program and the student- the answer decides the progress of the dialogue.

3

Vasta

4

Generating questions

5

Maid don lohket ikte? (What did you read yesterday?)Acceptable answers:

• Mun han lohken ollu áviissaid. (I HAN read manynewspapers.)

• Ikte mun gal lohken buori girjji. (Yesterday I GAL read agood book.)

• In lohkan maidege. (I did not read anything.)

• Ikte in lohkan. (Yesterday I did not read.)

6

Maid don lohket ikte? (What did you read yesterday?)Incorrect answers:

• Mun lohket ollu áviissaid. (Not agreement subj/verbal.)

• Mun lohken ollu áviissat. (Object should be in accusative.)

7

Steps

1. Analyse (morph-disambiguate) the question and answertogether

2. Common CG up until mapping. The disambiguation isincomplete, since we are careful with the errouneous input

3. Select the relevant reading

4. Make &err with assignment mapping rules

5. Give message to the student

8

Integrating the spellchecker in our ped program

We need a restricted spellchecker

Our normal spellchecker gives to many irrelevant suggestions

a. A pedogogically adjusted speller for all answers (cut theordinary speller with 50 % or more)?

b. A spell-checker for each question/answer?

9

Didactics more important than pragmaticsThe goal is to train morphology – therefore:

• No elipsis

• Finite verb compulsatory

• No inclusive 1st person dual and plural

• The answer I do not know is not accepted

10

Answer with the same verb

Solution: Sticky tag with regex (thanks to Tino)

Exceptional handling of pro-verbs

11

QDL is the delimiter between the question and the answer.

12

The errors are ordered:

1. spelling-error

2. verb: finit/infinit, what kind of verb,...

3. agreement subj/verbal

4. person/number and tense according to question

5. case of noun, according to question and argument of verb

6. case and type of numeral

7. PP: case and type of adp

8. agreement inside NP

9. time-expression, place-expression, some particles

13

Unintended lemmas, lexical levelHow to cope with unintended lemmas?

Problem e.g. viessut which can be a rare verb - Inf or finit, or acommon mis-spelling of viesut - Noun Pl Nom (= houses)Possible solutions:

• Remove problematic rare lemmas from the analyser (but notall of the problematic ones are rare)

• Make a lexeme-specific rule for the viesut N / viessut V pair

• Make a set of the problematic lemmas/word forms, andsubstitute or change the tag in the reading

14

Marginal morphological analysese.g. possessive suffixes> Remove them (when there is another reading)

When it is the only reading,e.g. Px & strong grade vs. Loc & weak grade:> Give a comment about it to the student

15

An example – from a test student

16

Nominative instead of accusative – a common errorThe question is how to deal with it when we cannot rely on theword order, and the subject may be ommitted

• The question asks for an object (but sometimes you mayeven answer without an Acc)

• Using sets:

• what are the required arguments of the verb?

• can it have HUMAN as an object?

17

HUMAN as an object?borrat (= to eat) - the HUMAN should be the subject, not theobjectlohkat (= to read) - you could read Ibsen

18

Sahka

19

What does the student answer?We need the answer to make a logical progress in the dialogue.

20

e.g. the answer should be an object:

21

Negative or affirmativee.g. if the student does not have a car, we do not want to askwhat car she has.Neg or aff as default – in case of difficulties in the analyse.

22

23

Namese.g. What is your name? What kind of car do you have?can be a N Prop (if in the lexicon) or a stringLIST QMRK = ? ;

24

Other possibilities for progressPicking the age with regexe.g. we do not want to ask a child if he has a car.

&dia-adult&dia-young&dia-child

25