A constructionist approach to student mo

A constructionist approach
to student modelling

Katrien Beuls
VUB Artificial Intelligence Laboratory
katrien@ai.vub.ac.be
Eurocall 2013, Évora, 11 September 2013

2

State-of-the-art language learning
systems promise “immersive learning”

Rosetta Stone
“Don’t learn a language, absorb it”

LANGUA

“Language learning should be natural”
Terminology of learning theories
(Acquisition-learning distinction,

Natural approach)

3

But they fail to accommodate
for individual student differences
Input is not very interesting
-

matching activities

-

elimination

Every student follows same path
irrespective of his answers
Similar to programmed instruction
of the early days of ITS
Krashen, S. (2013). Rosetta Stone: Does not provide compelling input, research reports at best suggestive, conflicting

reports on users' attitudes. International Journal of Foreign Language Education, 8(1), 1–3.
4

Academic initiatives try to counter
this lack of individualization
German Tutor (Heift & Schulze, 2007)
-

web-based German exercises

-

linguistic analysis for feedback

TAGARELA (Amaral & Meurers, 2007)
-

web-based language tutoring system
for Portuguese


-

annotations of learner input

5

I propose an active student model

That can predict a student’s answers
by simulating the learning task
It is implemented as a student agent
that can process and learn
the target language

6

A constructionist approach
to student modelling

1. Design of an agent-based language tutor

2. Operationalizing processing and learning
3. Ideas about tutoring

7

A constructionist approach
to student modelling

1. Design of an agent-based language tutor
A competent language user
A student model
Tutoring strategies

8

A language agent simulates
a competent language user

language agent
cxn

inventoryi
grammar
enginei
flexibility
strategies

A construction inventory (grammar)
An engine to process constructions
Flexibility strategies
to flexibly process the target language

9

e agent

A student agent
has the same architecture

student agent
cxn

inventoryj
grammar
enginej
learning
strategies

Instead of flexibility strategies,
the agent makes use of
learning strategies that target
specific acquisition problems
Also interacts with language agent
(no real student required)

10

Tutoring strategies mediate
the tutor-student interaction
tutor agent
language agent


student agent

cxn
inventoryi

cxn
inventoryj

grammar
enginei

grammar
enginej

flexibility
strategies

learning
strategies


tutoring
strategies

student
profile

11

The tutor agent’s student model
consists of a dual structure

A runnable student agent
-

predict student’s answers

-

align to student every interaction


A more static student profile
-

store user profile, preferences

-

update interaction logs and scores

12

A constructionist approach
to student modelling

2. Operationalizing processing and learning
Fluid Construction Grammar (FCG)
Spanish verb conjugation
Error correction

13


FCG lends itself well
for tutoring purposes

Construction-grammar formalism
Everything is a construction
(phon, morph, lex, phrasal, pragmatic)
A construction consists of features
Unification-based (HPSG) but less strict
Customizable search process

Steels, L. (2011). Design Patterns in Fluid Construction Grammar. (L. Steels, Ed.). Amsterdam: John Benjamins.
14

The formalism is informative
about failed constructional matches

Processing problems can be detected
when parsing student input
Uninterrupted processing guaranteed

with meta-level architecture

ía-past-imperfect-2/3
initial

jugar
1/3sg-morph

15

Language agent is initialized with
600 most common verbs in Spanish

18 x 6 conjugated forms / verb
+ 2 imperatives
+ 2 gerunds
= 112 forms / verb
Fred Jehle’s database contains
> 11 000 conjugated verb forms

Fred F. Jehle, University of New Mexico, Verb list taken from http://users.ipfw.edu/jehle/VERBLIST.HTM
16

Proficiency evaluated on
learner errors from SPLOCC II corpus
“The emergence and development of the
tense-aspect system in L2 Spanish”
408 errors made by
low intermediate learners
-

*cogue ➔ coge, ‘he takes’

-

*leó ➔ leyó, ‘he read’

-

*escuchían ➔ escuchaban, ‘they heard’

Evaluated by parsing and reproducing
Mitchell, R., Dominguez, L., Maria, A., Myles, F., & Marsden, E. (2008). A new database for Spanish second language
acquisition research. EUROSLA Yearbook, 8(1), 287–304.
17

SPLOCC results
unknown stem

!

43%

!

suffix change
100%

stem change

1%

verb class

unknown suffix

26%

12%

stem change
18%

accuracy

suffix change verb class
80%

unknown stem
unknown suffix
70%

18

The student agent is initialized
with an empty grammar

language agent

student agent

cxn
inventoryi

cxn
inventoryj

grammar
enginei

grammar
enginej

flexibility
strategies

learning
strategies

Empty construction inventory
Default grammar engine
settings
Learning strategies to acquire
target grammar

19

Learning strategies tackle
learning problems instead of
processing problems

diagnostics
D1
D2

repairs
problem-a

1.0

problem-b

0.5
0.2

D3
problem-c
D4
D5

0.3
0.9

R1
R2
R3
R4

0.1

problem-d

20

0.6

R5

Three types of learning strategies

Learning the basics
-

unknown stem, suffix

-

irregular verb

-

new grammatical meaning

Learning verb stem/suffix changes
-

coje < coger; pienso < pensar; ...

Learning verb classes
-

hablamos, comemos, vivimos
21

Learning happens in
discriminative contexts

Rosetta Stone Version 3, Spanish
22

The student agent can be
the speaker or the hearer in a game

student agent

1
cxn
inventoryj

1
parse

grammar
enginej

2

learning
strategiesj

3

1,2,3
find
topic

1
select
topic

consolidate

signal
success/
failure

produce

1,2,3
consolidate

situation

situation
language agent
cxn
inventoryi
grammar
enginei
learning
strategiesi

select
topic

game n

produce

signal
success/
failure

parse

game n+1

23

produce

find
topic

give
feedback

game n+2

t

Example: Three picking events
now

t

1

2

Student agent:
-

topic: event 2

-

utterance: “ha recojado”

Language agent:
-

correction: “ha recogido”

Student agent learns verb class
24

3

Communicative success reaches 100%
700

communicative success

500

80%

400
60%
300
40%

200

20%

100

0
0

0
2000 4000 6000 8000 10000 12000 14000 16000 18000 20000
games

Learning full conjugation of 25 verbs (mixed)
25

cxn inventory size

600

100%

Most learned constructions are suffixes

350

number of cxns

300
250
200
150
100
50
0
lex

suffix

irreg

Learning full conjugation of 25 verbs (mixed)
26

aux

gram

A constructionist approach
to student modelling

3. Ideas about tutoring
The Colour Tutoring Game
Tutoring strategies for learning problems
(work in progress)

27

First tutoring game prototype
for colour word learning

Web interface with colour chips
User can be student or tutor
(teach the system a colour lexicon)
New colour lexicon can be used for
future students
Beuls, K., & Bleys, J. (2011). Game-based Language Tutoring. In B. Knox (Ed.) Proceedings of the IJCAI 2011 Workshop
on Agents Learning Interactively from Human Teachers, Barcelona.
28

The colour tutoring game
is lacking tutoring strategies

Tutoring strategies serve two functions
1. Selecting a new situation
2. Providing constructive feedback
Spanish verb tutor should tackle
learning problems that are diagnosed

29

Alignment is critical
for a predictive student model

The tutor agent needs to align
the linguistic knowledge of the student
with the constructions known by the
student agent after every game

30

Conclusions

The language agent and the student
agent form the basic foundations for an
adaptive tutoring system for language
Using Construction Grammar to
represent linguistic knowledge is
beneficial for understanding the
student’s difficulties

Work in progress...
-

Building a user interface

-

Developing tutoring strategies
and a data structure they work on

-

Experiments with alignment

Possible future extensions lead to
-

other game scenarios

-

larger sentences

-

more languages

Further reading
Beuls, K. (2012). Grammatical error diagnosis in Fluid
Construction Grammar: A case study in L2 Spanish
verb morphology. Computer Assisted Language
Learning. doi:10.1080/09588221.2012.724426.
Beuls, K. (2012). Inflectional patterns as constructions:
Spanish verb morphology in Fluid Construction
Gammar. Constructions and Frames, 4(2). p 231-252.
Steels, L. (Ed.). (2011). Design Patterns in Fluid
Construction Grammar. Amsterdam: John Benjamins.
Steels, L. (Ed.). (2012). Computational Issues in Fluid
Construction Grammar. Berlin: Springer.

Additional slides

Flexibility strategies
are active during linguistic processing

R2
R3

R5
problem-b

R4
R1

problem-a
restart

restart

problem-c

D1

37

D4

no
restart

R3

Constructions relate meaning to form via
semantic and syntactic categorizations

meaning

form

semantic
categorizations

syntactic
categorizations

38

Detect feature mismatch
ía-past-imperfect-2/3
initial

jugar
1/3sg-morph

Second merge fails due to
different verb class feature in stem
ía = 2/3; jugar = 1
Diagnostic returns verb class feature
and its correct value

39

Detect unknown stem

Very frequent problem with beginning
learners
juqaba => jugaba
Repaired with closest match on stems in
grammar
Levenshtein distance with additional
weight on first letter

40

Learning problem priority list
Front

Back

LP1

LP2

LP3

LP4

LP5

LP6

LP7

LP8

FI = 0.7
LET = 0.4
1 > FI > LET

LP9

1

2

LP10

3

...

Back

Front

LP8

LP3

LP2

LP4

41

LP5

LP6

LP7

LP1