in the presentation, description and
operationalisation of the concept (R). The analysis
of word problem, together with the study of the
processes and symbolic representations used by
students when discussing and solving word
problems, is the key element of the above-mentioned
theory (Vergnaud, 1991).
Vergnaud (1986, 1991) asserts that, in order to solve
a word problem, one must employ a great number of
theorems, i.e. knowledge equivalent to the properties
of a concept. When doing so, one resorts to abilities
and knowledge that Vergnaud (1986, 1991) names
theorems-in-action. In short, theorems-in-action
refer to representations of the relevant aspects of the
action in question. Indeed, these representations
reveal only the essential aspects of the action.
In more practical terms, one could speak of concrete
elements (such as sticks, marks on paper, fingers) as
the invariables employed. Since the response offered
would certainly not be the quantity of material used,
but rather the quantity about which the question asks
through the representation, the objects used are not
relevant; instead, what matters is the result.
Although word problems are worked on all through
elementary and secondary school, their diversity is
not fully explored as that would require the use of
numerous situations involving countless invariables.
What one normally does use is a limited range of
additions, subtractions and properties of these
operations. Similarly, the number of forms of
symbolic representations of these operations is also
limited (e.g. Charlie has 6 cars and Paul has 8. How
many cars do they have altogether?). This kind of
limited work makes students employ a reduced
amount of specific knowledge and present
difficulties when solving other problems which, in
turn, require the use of different meanings,
properties and representation forms.
An instance of word problem characterised by
change would be the following: “Mary used to have
14 letter papers. Her mother gave her 8 more. How
many letter papers does she have now?”, whereby a
change happens to an initial number, resulting in a
new number. In other words, an initial number goes
through a direct or indirect transformation, causing
this initial number to grow either bigger or smaller.
As we can see, the idea of time is implicit in a word
problem like this one, making it an invariable that
needs to be taken into account in order for one to
find the solution.
Vergnaud (1986) divided addition and subtraction
problems – isolated or combined over natural,
integer or real numbers sets – into six categories.
Carpenter and Moser (1982), as they explore natural
numbers only, divided the problems on four
categories: combination, comparison, change and
equalisation. These 4 categories give rise to 16
different situations, depending on where the
unknown number is located.
The Carpenter and Moser (1982) classification was
adopted by Leite, Borba and Gomes (2008), which
proposed a help-function using a different diagram
form for each one of the four problem categories.
4 VIRTUAL ENVIRONMENTS
AND THEIR MULTIPLE
REPRESENTATIONS:
SUPPORT TO TEACHING AND
LEARNING ONCLUSIONS
The Theory of Multiple External Representations
(Ainsworth, 2006) is a cognitive theory that
advocates the use of specific techniques to represent,
organise and present knowledge. MERs have the
following three key functions: complementary roles,
constrain interpretation and construct deeper
understanding.
The first function, “complementary roles”,
explores representations that, for being of different
types, complement each other and offer support to
the cognitive process. The main objective of the
“constrain interpretation” function, on the other
hand, is to use representations that helps the learner
to avoid misintrepretations about the concepts in
question. Finally, the “construct deeper
understanding” function uses MERs as a tool for
helping the learner to buid abstractions about the
concept and organize it in a higher level.
According to Ainsworth (2006, 2008),
representations may appear simultaneously or
alternately. Either way, learners must be able to
understand the form of representation, its relation to
domain, how to select an apropriate form of
representation and how to create an appropriate one
(Ainsworth, Wood, Bibby, 1996). This way, one can
construct new representations and access other
representation options which, in turn, help expand
the conceptual field in question.
Having a wide range of representations may
result in more effective learning conditions,
particularly when these representations provide
learners with a more in-depth view of the concept in
question, or when they suit the user’s cognitive
model. Furthermore, making use of more than one
representation type may help grab the students’
attention for longer (Ainsworth, 1999).
A USER-INTERFACE ENVIRONMENT AS A SUPPORT IN MATHS TEACHING FOR DEAF CHILDREN
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