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Tradeoff and Cognition: Two hypotheses regarding attention during task-based performance Peter Skehan Chinese University of Hong Kong Second International Conference on TBLT University of Hawaii, Sept. 20 th – 22 nd 2007
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Conceptualising performance on tasks Three areas typically measured in task research studies –Complexity (C) : How advanced (often interpreted as subordinated) the language is –Accuracy (A) : The extent to which error is avoided –Fluency (F) : How fast, smooth, uninterrupted performance is Sometimes a contrast between general and specific measures Sometimes a tenuous acquisitional sequence
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The Limited Attention Approach aka: The Trade-off Hypothesis 1: Attentional capacity is limited Attending to one performance area may take attention away from others Under certain conditions, raised performance in one area may be at the expense of performance in other areas Task difficulty will be associated with lowered performance in some areas, and complexity and accuracy (particularly) compete
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The Trade-off Hypothesis 2 Task research has explored the influence of task characteristics (e.g. task types, such as personal, narrative, decision-making, and also some specific variables, e.g. interactivity) and task conditions (e.g. pre- task planning; length of time a task is done; post-task conditions) Some of these simply affect difficulty –e.g. more participants raise difficulty
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Tradeoff 3 But some task effects are directing, e.g. –Information integration raises complexity (T+S 05) –Structured tasks lead to greater accuracy (S+F 99) –Tasks based on familiar information lead to greater fluency (F+S 96) And some task conditions also direct, e.g. –Planning raises complexity and fluency (F+S 96; O 05) –Post-task activities raise accuracy (S+F 97: S+F ms)
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Tradeoff 4 Task characteristics and task conditions can have selective, directing effects Some effects influence more than one performance area, e.g. planning Combinations of effects may therefore be possible Research findings can show how to attentuate the impact of tradeoff
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Trade-off 5 Levelt and stages in speech production –Conceptualiser Outputs the pre-verbal message Reflects organisation of ideas and choice of stance Main performance manifestation: Complexity –Formulator Lexical encoding Triggering syntactic encoding Main performance manifestations: Accuracy/Fluency –Articulator Conceptualiser as the driver for complexity? Formulator as the main arena for trade-off effects?
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Contrasts in the nature of the two accounts Robinson is a theory-then-research account –Theory of attentional functioning –Theory of task complexity Skehan is more research-then-theory –Assumption of pervasive limited capacity –Low level predictions of influence of different variables, and studies investigating one or two variables at a time –Modification/accumulation of findings, and extension of basic account to enable tradeoff circumvention
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Contrasts (cont.) Robinson’s theory is therefore more intricate, and makes complex predictions about relationships It is also, for me, a little counter-intuitive (which isn’t at all bad!) Skehan’s theory is more minimalist and empirically-based It takes accumulated, basic findings and pushes them as far as possible
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How can we test the two hypotheses? Broadly, Robinson predicts that: –Task complexity will raise both language complexity and accuracy and reduce fluency Therefore experimental manipulations which, e.g. use there-and-then, or greater spatial demands, etc, will push up complexity and accuracy, while lowering fluency Robinson doesn’t predict (but should predict?) that on more difficult tasks accuracy and complexity should correlate
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How can we test: Cont. Skehan predicts that: –Some influences will be general, and will provoke trade-off consequences –Other influences will be selective Understanding these will come from empirical research Some predictions will be limited and selective Other predictions will involve combinations of independent influences Some of these will lead to combined influences, including jointly raised accuracy and complexity
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Here-and-now vs. There-and-then Robinson (95): TnT was more accurate, HnN showed fluency trend. No complexity difference Rahinpour (97): Broadly similar results Iwashita (01): TnT more accurate. No other differences Ishikawa (07): Written performance: CH received support on specific and some general measures of Com. and Acc. Gilabert (07): Planning and HnN/TnT: Planning had customary effects: TnT produced more self-repair (accuracy) and lower fluency Conclusion: Accuracy only for TnT: Fluency and HnN
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Perspective taking: Robinson 2000, in press Narrative picture sequences for WAIS –Three ‘levels’ of increasing understanding of intentions to effectively sequence pictures and narrate a story –General and specific measures Significant difference for TTR only, against predicted direction. Complexity, accuracy, fluency unaffected Little support
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Conclusions: Cognition Empirically, the support from Robinson-linked research is mixed. Accuracy for TnT does appear, but not complexity or joint accuracy-complexity Perspective also fails to be supported Alternative analyses of HnN vs. TnT are possible The justification of these variables as more complex and so resource-directing needs to be strengthened
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Supporting Cognition? : Foster and Skehan (99) Decision making task (losers in a balloon) Planning source (teacher, group, individual) and focus (language, content) Teacher based planning clearly most effective Accuracy and complexity were both raised Interpretation: effective preparation through ideas and through rehearsal/anticipation Planning can have multiple (Conceptualiser and Formulator) functions
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Supporting Cognition? : Skehan and Foster (ms) Decision making and narrative tasks Post-task condition: transcribe one minute of your own performance Hypothesis: Foreknowledge of this task would push attention towards accuracy Result: Both accuracy and complexity were raised Interpretation: attention has to be focussed, but with the right conditions, it can be, but to form-in- general
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Supporting Cognition? : Tavokali and Skehan (05) Narrative picture series Increasing degree of structure, (Winter-Hoey and problem solution structure) More structured tasks produced greater accuracy and fluency One of the structured tasks also generated greater complexity: This was because there was a need to integrate background and foreground information Interpretation: Two task features interacted to support accuracy and complexity separately
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The role of lexis Lexis-as-variety (Lambda), and lexis-as-TTR (D from CLAN) They don’t correlate Lambda has negative correlations with accuracy and complexity Tasks with heavy and hard-to-avoid lexical demands lead to lowered accuracy and complexity This speaks against a task-complexity driven increase in language complexity and accuracy in the second language case
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Assessment of evidence Basically, the Robinson-based evidence for the Cognition Hypothesis is not strong –Accuracy and complexity are rarely jointly raised in research by Robinson or colleagues –Findings of this relationship come from others –What then, can we say about these cases?
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The three ‘positive’ studies Note: no correlation between accuracy and complexity in these cases (or ever reported) Two ‘condition’ studies. –One is of effective preparation, requiring ideas and expression. (Planning is resource- dispersing) One is of attention focussing, predicted for accuracy but actually complexity also. Neither involves task complexity The third study shows conjoint influences of task characteristics, which I assume work separately to produce the result that they do
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The fruitfulness of using Levelt The Conceptualiser stage influences complexity, the Formulator is more concerned with accuracy There-and-then is easier to handle in the Formulator, since input demands are much lower F+S 99: Teacher based planning: Effective Conceptualiser work and Formulator easing –Planning can have multiple foci, and multiple effects T+S 05: Structure provided a task macrostructure, and eased Formulator operation: Information integration pushed Conceptualiser use, especially as indexed by subordination
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Partial evidence for Cognition? S+F ms: Post-task influence: Essentially, heightened attention to form The effect on accuracy is reasonable: attention directed towards the Formulator, because of the experimental condition Why complexity? Actually, not so strong an effect, but just there. Speakers do seem to want to achieve precision and use demanding language. Key issue: One cannot say that this was driven by difficulty Let’s stick with Levelt!
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Pedagogic Implications 1 What we know is partial and it is also fragmented –Insights about task characteristics –Insights about task conditions –Insights about combinations of characteristics and conditions The usefulness of this information depends on: –Either having clear performance goals (CAF) –Or believing in a linked acquisitional sequence
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Pedagogic Implications 2 A potential sequence –Complexity > Accuracy > Fluency Choose tasks and task conditions to promote this sequence, such that new language is used, then control is gained over this language so that error is reduced, and then fluency-lexicalised language is achieved This is, basically, speculative
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Pedagogic Implications 3 We have not solved the problem of task difficulty –Therefore we cannot rely upon sequencing tasks in a difficulty order We have made progress in rating difficulty, fairly consistently, but this connects with performance only slightly Perhaps now we have to say that analysing the lexical demands of tasks is particularly important
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Pedagogic Implications 4 Develop planning –Explore different approaches to planning Train planning –Help learners to get better at pre-task activities which Push the Conceptualiser to greater ambition Anticipate problems, especially lexical Rehearse effectively to ease subsequent Formulator operations
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Pedagogic Implications 5 At the post-task stage, nurture, consolidate, and complexify new language which emerges through performance –Exploit the post-task phase, not simply for Machiavellian attention manipulation –Use language whose salience has just been realised and: practise it, build upon it integrate it recycle it
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