Information Technology Reference
In-Depth Information
4.3 Exploratory Learning by Playing with Meme Media
When the target of learning is not just one algorithm, but several alternatives,
like in fields such as searching and sorting (think only of the fine difference
between
Heapsort
and
Bottom-Up Heapsort
), there are varying opportunities for
didactic concepts based on the competitiveness of the algorithms.
For teaching pattern inference, in general, and aiming at an understanding
of the Lange/Wiehagen algorithm
A
and variations such as
A
,inparticular,
there are many ways of making the studies exciting.
Here is one task teachers may assign to their students:
Find some sequence of
strings as short and simple as possible such that after processing this sequence
the Lange/Wiehagen algorithm returns a string without variables, whereas the
Jantke/Grieser refinement leads to some hypothesis which consists of variables,
exclusively
.
Fig. 7.
Webbles implemented by Jun Fujima (Fraunhofer IDMT, Erfurt) in HTML 5
for the playful exploration of the Lange/Wiehagen algorithm and some of its variations
This example problem is not that easy to solve. Some students need several
approaches before they arrive at a solution. The screenshots of figure 7 show the
results of processing the three strings
abbaaabbbba
,
aaaaaabbaaa
,and
babbbbb
.
The two alternative results are
babbbbb
and
x
1
x
2
x
1
x
1
x
1
x
3
x
1
.
