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

Figure 6: Two pupils presenting their conception of
airport baggage handling after they were introduced
to the context by a YouTube video.
Starting with the first stage of the proposed model, the
pre-educational stage, the students began to analyze the
context of baggage handling. First, they searched the Internet
to find diverse artifacts describing the context. The students
found pictures, videos and technical documents some
of which could also be used as (secondary) context artifacts.
Furthermore, they had the chance to visit an international
airport and to inspect the baggage handling system on site.
They took notes and additional pictures and had interviews
with domain experts.
Moreover, since we used the Greenfoot as a framework
for the development of a “micro baggage handling world,”
the students had to learn how to develop Greenfoot scenarios
with professional development tools 3 . For the school
project the students implemented a Greenfoot simulation of
an airport baggage handling system. They modelled animated
passengers who check in their luggage and go to their
flights while their luggage is transported to the correct airplane.
The context artifacts Greenfoot scenario, the interviews,
photos, videos and further documents were the result
of the first stage.
At the educational stage the context artifacts and educational
standards were used to develop teaching units. The
developed teaching units consisted of a timetable, descriptions
of basic definitions and concepts and different exercises.
For example, the pupils were introduced to the context
of airport baggage handling by videos and prosa text.
After that they were to draw a schematic of the BHS (figure
6).
In another teaching unit the boys and girls started to investigate
a Greenfoot simulation of a BHS, that intentionally
exhibited some serious problems. After a few minutes the
baggage cumulated on the conveyor (figure 7). The first exercise
was to figure out the problem and to rearrange the
layout of the conveyor system. This was done by drag-anddrop
and interactively exploring the objects’ interfaces.
3 As a didactical programming environment Greenfoot is not
well suited for professional teamwork or code refactoring.
Therefore we use both Greenfoot and Eclipse for the development
of the Greenfoot scenarios.
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Figure 7: Greenfoot simulation of an airport baggage
handling system, used in the school projects of
2010 [31]. In this scenario the BHS layout is flawed
so that after a few minutes the conveyor system is
jammed with luggage.
In this section we have illustrated how we have used the
model in order to bring the context of baggage handling into
the classroom. We have described the decontextualization of
context artifacts based on informatical principles and supported
by the Java programming environment Greenfoot.
In the second stage of the proposed model we have developed
teaching units using the context artifacts. The designed
teaching units have been brought into the classroom
during different school projects. The feedback, we received
from the pupils, were mainly positive because they enjoyed
to get insight into complex real world context like baggage
handling.
6. DISCUSSION
The proposed process model has been developed in a specific
course setting with multiple subprojects. The different
roles and the division of work established in our project
are obviously reflected in our model. Thus our model may
not hold universally. Nevertheless we argue that the division
of work in our project results from the fact that the
different contexts involved are essentially separated in the
first place. After the discussion of the our methodology, we
therefore consider other possible constellations and a fundamental
dilemma for Informatics teachers – especially at
school.
6.1 Model Validity
Although the process model for bringing contexts into the
classroom is so abstract that it can only serve as a reference
framework, there is good reason to challenge it. In our
projects it has been proven to be viable, but further inquiries
may remain necessary. Nevertheless we claim ‘validity by design’
for our model arguing along the following principles for
design-based research in IS, that were introduced by Hevner
et al. [17]:
Design as an Artifact. The goal of design-based approaches
is the creation of appropriate and reliable artifacts,