This is an educational model and therefore its main goal is
to teach people. In this case the students will be
taught the principle of A star search algorithm.
This tool targets A-level and possibly University
students and therefore the level of understanding
of the subject should be quite high. There will be
two main modes: tutorial and quiz.
In tutorial mode the principle is going to be
explained together with the demonstration of how
the algorithm works in an exemplar case. The
concept behind the algorithm is going to be
explained in words.
In order to increase understanding a demonstration
will be used. The example will simulate a problem
of getting from St Andrews to Canterbury. The
heuristic function will be represented by the
distances between cities (in km). The screen will
have the graph representation of the map with nodes
being cities and vertices paths from one city to
another. At each point in time when the target has
not been reached (the person is not in Canterbury)
there will be a “select next city” button
available. By pressing this button the user will be
showed the next node selected by the algorithm. The
current path (from the starting point (St Andrews)
to the current node) will be highlighted with
green. The system will also display information
about the current value of the heuristic function
f(n). Each node connected to the current node will
have information about the values of g(n) and h(n).
At any point in time the user would be allowed to
go to the quiz mode.
The quiz mode will present a different example of
the same problem (going from one city to another).
The user will be presented with the information
about the current status of the system i.e. which
node is selected and the values of heuristic
functions for the nodes connected to the current.
The user is then asked to select the node he or she
thinks is going to be selected by the algorithm.
Having done that the user will receive the feedback
as to whether the choice was correct. After
completing the task the total of correct and
incorrect answers will be displayed. If the user
should experience problems at any point they will
be allowed to cancel the quiz and go back to the
tutorial mode. However this action will reset the
current progress.
