Maria Knobelsdorf, University of Dortmund, Germany - Didaktik der ...

3. DUAL NATURE CONCEPT
The concept (and term) ‘structure’ is borrowed from the philosophy
of technology (see [31] for details). Due to the dual nature of
technical artifacts, there is the need to understand the function of a
technical artifact as well as its internal design, the structure (structure),
in order to fully understand it.
Function captures the perspective of the use, and the purpose of
the artifact: What should it be used for? What can be done with it?
structure describes the internal mechanics: How it is made, how it
works and which concepts are used in its (internal) design.
Note, that ‘structure’ – in difference to the use of this term in
computing – includes (data) structures as well as algorithms and
processes.
The need to understand the internal ‘mechanics’ or ‘principles’
underlying the perceived function (functionality) is not restricted
to use. It is also acknowledged as a problem for novices learning
programming, in [3], [23], and [34] similar dual conceptions are
proposed. From now on and the rest of the article we use the terms
‘structure’ and ‘function’ to refer to this philosophical meaning.
The concept proposed here is to uncover structure behind function
(by experimenting); and thus bridging the perceived gap between
function and structure for Outsiders. But at the same time, structure
is still in focus, so that such teaching units should be of interest
and motivating for Insiders, too.
The key idea is the perception of the dual nature of digital artifacts,
which can be described by structure and function. Function
is implemented by structure, and structure is designed with a
purpose in mind; hence both are closely connected. Ideally, there
is a ‘harmony’ between structure and function.
Based on structure-knowledge, it should be easier to predict (and
expect) certain functionalities in digital artifacts, to predict and
expect certain ruptures, and to understand and memorize tactics
and strategies in the use of digital artifacts (for such examples, see
e.g. [3]).
Vice-versa, based on function-knowledge, it should be easier to
evaluate such an artifact. If a person truly understands the purpose
of an artifact, she is better able to assess whether the chosen and
implemented structure (the technical ‘solution’) fits the user expectations.
Without such an integrated understanding one is only
able to state being unable to carry out the desired purpose with the
tool – but not whether such usage problems are due to features of
the structure.
Of course, this duality is an analytical concept; in ‘real life’ there
exist only ‘complete’ digital artifacts – but the duality highlights
typical pattern of perceiving and understanding such artifacts.
A last issue is the notion that immediate ‘jumping into’ discussing
structure by a teacher might slow down the learning process,
because learners are missing important aspects (namely the function)
needed to really understand and memorize the teaching
content. Even worse, if they don’t grasp the function related to
structure, they aren’t able to see the usefulness of the learning
content at all.
3.1 Discussion of possible misconceptions
In this section some important aspects of the concept are rephrased,
in order to discuss some misconception the author noticed
when presenting the concept.
These misconceptions might be due to the education of the typical
audience of computing engineers. As Kroes [19] discuss, engineering
education can be interpreted as learning to bridge struc-
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ture and function – so to speak automatically and unconsciously.
Therefore engineers are trained to overlook the gap and therefore
are likely to regard the concept as not really important, as the
main problems of the engineer are to refine and produce a suitable
technical solution (the structure) for a given description of the
function.
1) The first misconception is therefore the notion that duality
refers to the gap between the outside and the inside: The
function is perceived by the (external) user, whereas the
structure is in focus of the engineer, who focusses on the inside.
In fact, the duality can be observed for or within every
part of a digital system. Think e.g. about abstraction and the
layered model of network protocols. Each layer is used for
the next one, and itself hides the internal structure. Another
example is abstract data types: Again, we see abstraction
from structure, so that the engineer can focus on using the
data type. (Note, however, that e.g. the java library gives
hints about the internal structure when naming classes like
ArrayList or LinkedList – so that the user of the class has
some information whether it is better to use ArrayList of
LinkedList, also the functionality is the same)
2) The second misconception, related to the first one is that
people have problems declaring an aspect as structure, and
another as function. It seems easy when looking at inside/outside
the whole system (see misconception one). But
is an ArrayList a function or a structure? The answer is – of
course – that it is both. Every part of a digital artifact as well
as the whole can be perceived from either the viewpoint of
function, or from the viewpoint of structure. Because the artifact(s)
embody a dual nature: The need to be understood in
terms of function, of structure and in terms of their dual nature,
there specific link between both sides. (The crucial observation
from philosophy of technology is that a) it is quite
hard to see both sides of the coin at the same time and b) that
the two sides are based on quite different ontological and
epistemological grounds)
3) Misconceptions regarding structure: structure seen as in data
structure, and missing e.g. algorithms or any other dynamic
aspect of the implementation. Of course, structure is not a
term from computing (as it is used here), but from technical
philosophy and as such encompasses the mentioned aspects.
A similar term used in computing might be mechanism.
4) Misconception regarding function: as function as it is used in
computing: the functionality, or as the use of the artifact, its
design goals, requirements. To refer to the example used
above, the dichotomy was mechanisms and goals. Similarly
intention could be used. However, such an impression is too
narrow, as function also includes the impact which was not
intended (or as an engineer might say: mal-function).
5) Another misconception might be triggered by the use of the
terms insider and outsider, which associate the superiority or
preference for insiders. While it is a legitimate goal to foster
interest for computing, the main goal of this approach is fostering
self-determination - which includes of course the legitimate
decision not to study computing. But such decisions, as
well as a so-called Outsiders attitude towards digital artifacts
should be based on a somewhat truthful perception of the
discipline and the nature of digital artifacts.
4. Changing computing education
In the end, this approach strives for a change in computing education
on the school level. As can be seen in natural science or math,