Modelling study

As stated above, this model must be able to visually demonstrate the concept of a depth first and breadth first searches. In order to teach these algorithms it is necessary to offer two different ways of working, a demonstration style guide to the algorithms and an interactive mode where the user is responsible for choosing which node they think should be searched next.

The demonstration mode will provide the user with a visual guide as to how the search is being performed. They will be shown the search starting at the root of the tree and then as it progresses from node to node they will be able to see the order in which it traverses and the nodes which are put in the queue to display later.

The quiz mode will be used to test students as to whether they have understood the concepts behind the search. They will be presented with various different data sets which will be shown in a tree format and will be responsible for clicking the node which they believe to be the next one to be explored. The program will then give them feedback as to whether the node that they clicked on was correct. If it is correct, the node will be highlighted green and the child nodes will be added to the queue. If it is not correct, the user will be given an option to choose another node or to have the program suggest a node.

When the screen initially loads up, there are three pieces of information which the user needs to see in order that this program work successfully as an educational tool. They must be able to see the tree that is to be searched, the item being searched for and the value of the queue at any time. These will be presented on the screen so that the state is immediately visible.

When demonstrating or in quiz mode, all nodes which have been considered will be displayed in a green circle, with all their child nodes displayed in blue. Once a node has been fully explored it will turn red. This colour coding will help the user identify what is happening at any stage in the algorithm.