K. PHILIP CHOONG and ZHAOHONG HANTeachers College, Columbia University

kpc2001@columbia.eduhan@tc.columbia.edu

Task Complexity and Output Complexity:

An Exploratory Study

Motivation

Cognition Hypothesis

Question: What is the relationship between task complexity and output complexity?

Is there a relationship between task complexity and output complexity?

If so, what is the nature of the relationship?

Operationalization of Task Complexity

Dimensions

Contextual support Reasoning demands Single/Dual Task

DimensionsDimensions

Contextual support

Dimensions

Contextual support

Dimensions

Reasoning demandsContextual support

Dimensions

Reasoning demandsContextual support

Dimensions

Single/Dual TaskReasoning demandsContextual support

Dimensions

Task: Story narration

Task conditions

+/-picture

+/-sequence

(C1)+ picture/+sequence

(C2)- picture/+sequence

(C3)+ picture/-sequence

(C4)-picture/-sequence

-Complex

+Complex

Design

Repeated measures

Experimental Group Comparison Group 1 Comparison Group 2

Participants

Experimental group: 10 native Japanese speakers from advanced ESL classes in New York City Average age – 38 Gender- 9 females and 1 male

Comparison Group 1: 5 native speakers of American English Average age: 33 All females

Comparison Group 2: 10 native speakers of American English

Procedure

Task: Story narration under 4 different conditions

4 stories vis-à-vis 4 conditions Instructions

I am going to show you a set of pictures that tell a story. Please take as long as you like to look over the pictures, then tell me the story as if I cannot see the pictures. We will do this twice. The first set will be practice, just to make sure you understand the instructions. There is only one “correct” story for these pictures.

Example

Measures of Output Complexity

Syntactic complexity # of T-units per narration

Content complexity # of idea units per narration

Analysis and Results – Experimental group

Friedman Test and Kendall’s W Test of Mean rank

Both produced same results, significant at .05 level

Friedman Test of Mean Rank (Kendall’s test similar) Condition Mean Rank

C1_T-unit 2.45C2_T-unit 2.00C3_T-unit 5.15C4_T-unit 3.90C1_I-unit 4.55C2_I-unit 4.25C3_I-unit 7.55C4_I-unit 6.15

Results- Form ComplexityCondition 3 (+reasoning demands, +contextual support) most complexCondition 2 (-Reasoning demands, -contextual support)Least complex, least variationCondition 4 (+Reasoning demands, -contextual support) shows most variation C4_TC3_TC2_TC1_T

18

16

14

12

10

8

6

95%

CI

Form Complexity and Variation by T- Unit

Results-Content complexityGreater variation in content complexity than in form complexity

In line with Friedman’s and Kendall’s W tests of mean rank.

Also supported by paired sample t-test

C4_IC3_IC2_IC1_I

24

21

18

15

12

9

95%

CI

Content Complexity and Variation by Idea Unit

Results – paired samples t-testSignificant differences between conditions 1 and 3, 2 and 3, and 2 and 4

Both for Form complexity (t-units) and for content complexity (idea units)

Contrastt-value df Sig. (2-tailed)

C1_T - C3_T-3.160 9 .012

C2_T - C3_T-4.371 9 .002

C2_T - C4_T-2.785 9 .021

C1_I - C3_I-2.918 9 .017

C2_I - C3_I-6.050 9 .000

C2_I - C4_I-2.293 9 .048

Results – individualGreater number of idea units may suggest that participant was more focused on content than form.

4321

Condition

30.00

25.00

20.00

15.00

10.00

5.00

0.00

Mea

n

IdeaUnitT_Unit

Shihoko

Results-Comparison Group 1

Native speaker results are parallel to non-native speaker results in terms of:

Syntactic/Content Complexity:

C3>C4>C1>C2

Results – Comparison Group 2

Rankings of difficulty of picture sets

C3>C4>C1>C2

Discussion

+contextual support+reasoning demands

-contextual support+reasoning demands

Finding 1: More complex conditions produce more complex output.

Reasoning demands

C3 C4

Discussion

Finding 2: Gap between the “contrived complexity order” and the “observed order of output complexity”

Contrived complexity: C4>C3>C2>C1Observed complexity of linguistic output:C3>C4>C1>C2

Task intrinsic complexity: C3>C4>C1>C2

TaskInternal

complexity

+/-picture

+/-sequence

Discussion

Finding 3: Patterns of variation differ for the experimental group vs. comparison group 1. Experimental group:

Syntactic complexity: C4 C2 Content complexity: C1 C2

Comparison group 1: Syntactic complexity: C1 C2 Content complexity: C4 C2

Content complexity and form complexity are unequal.

Limitations and Next Steps

Further data analysis Fluency as well as accuracy Lexical complexity Syntactic complexity in terms of S-nodes per T-unit

Conclusion

The jury is still out.Task complexity is a complex notion requiring

finer-grained analysis than has generally been given. More conceptual work is needed. In examining the relationship between task complexity

and output complexity, there is a need to differentiate between content complexity and form complexity, and more importantly, to investigate how attention is allocated to form and content during task performance.

There is a need to track down the differential impact of task-intrinsic complexity and contrived complexity

More attention should be given to task-intrinsic complexity

Conclusion

Grading Complexity and difficulty Complexity dimensions Granular analysis of complexity (e.g.,

conceptualizer, formulator, and articulator)Effect size Perceptions of complexity