DeFT: A conceptual framework
for considering learning with
multiple representations
指導教授：Chen, Ming-puu
報 告 者：Jheng, Cian-you
報告日期：2007/07/17
Ainsworth, S. (2006). DeFT: A Conceptual framework for considering learning
with multiple representations. Learning and Instruction, 16(3), 183-198. 1
1.Introduction
• Multiple (external) representations can
provide unique benefits when people are
learning complex new ideas.
• effectiveness of representations
– sensory channel
– modality of the representations
• review of research on Multiple external
representations (MERs)
• DeFT (Design, Functions, Tasks) framework
2
2.Design parameters in DeFT
• Number
– at least two representations
• Information
– flexibility/distributed over representations/
redundancy of information between representations
• Form
– pictures/text/animations/sound/equations/ graphs
• Sequence
– decide at what point to add a new representation or switch
between the representations.
• Translation
– how active a role the environment plays in supporting
learners.
– whether support is provided
3
3. Learning with an external representation
3.1 The functions of an appropriate representation
• Computational offloading
– different external representations reduce the
amount of cognitive effort required to solve
equivalent problems.
• Re-representation
– the way that external representations that have
the same abstract structure differentially influence
problem solving.
• Graphical constraining
– the limits on the range of inferences that can be
made about the represented concept.
4
3. Learning with an external representation
3.2 Cognitive tasks involved in learning with an
external representations
Learners should understand:
• the form of representation
• the relation between the representation and
the domain
• how to select an appropriate representation
• how to construct an appropriate
representation
5
4. Learning with multiple representations
6
5. Functions - Complementary functions
• Complementary processes
– Individual differences
• learning styles
– Task
• choosing the best representation for the current
task.
– Strategy
• encourage learners to try more than one strategy to
solve a problem.
• Complementary information
7
5. Functions - Constraining functions
• One representation constrains interpretation
of a second representation.
– One representation constrains interpretation of a
second representation.
– taking advantages of inherent properties of
representations. (graphical v.s textual)
8
5. Functions - Constructing functions
• the basis for new procedures and concepts at
a higher level of organization.
• extending knowledge (known → unknown)
– Ex: velocity-time graph /
tables or acceleratione-time graphs
• Relational understanding
– Ex: graph / equation
9
6. Cognitive task
learners may need to understand how to relate representations
6.1 Representation characteristics
• The sensory channel of the representation
– auditory / visual
• The modality of the representations
– text / graphical / diagrammatic
• The level of abstraction
• The specificity of representations
– the extent to which a representation permits
expression of abstraction
• The type of representation
– histogram, equation, table, line graph, narrative
text, picture
10
6. Cognitive task
learners may need to understand how to relate representations
6.1 Representation characteristics
• Integrated presentations of representations
– presenting integrated material rather than
separately presented material
(textual and graphical representations)
• Whether representations are static or dynamic
– different types representations also have different
format and operators.
• Dimensionality
– virtual reality and other visualisation tools
11
6. Cognitive task
learners may need to understand how to relate representations
6.2 Individual characteristics
• Representational familiarity
– format
– operators of representation
– relation between the representations and the domain
• Domain familiarity
• Age
• Individual differences
individual factors and representation factors
influence the strategies that learners use
12
分
數
分數表徵(Lesh et al., 1987b)：
• 操作具體物表徵
– 如：古氏積木（Cuisenaire rods）、百格板、圓形分
數板、數線、花片等
• 圖形表徵
– 如：圖表、數線、長條圖、面積圖
• 符號表徵
– 如： 1/3+2/3 =1
• 口語表徵
– 口語陳述，以表達想法或解題過程，如三分之一。
13
分
數
• 圖形模式(graphical mode)：探索各種圖形變化。
• 數值模式(numerical mode)：對應數值的變化。
• 文字模式(text mode)：問題的呈現或說明。
曾振家(民90)。國小五年級學生在動態多重表徵情境下建構分數加法概念
之研究。國立臺南大學國民教育研究所碩士論文，未出版， 台南市。 14
Thanks!
15