The Multi-Quadrant Analysis can be found in the Tools menu. The network must have a database and a target node. This tool allows analyzing a network having a Breakout variable. For each state of this variable, one of the three available analysis will be performed on the variables of the network with respect to the target. In this way, it is possible to analyze the behavior of each variable with respect to the target for each state of the breakout variable and to compare those behaviors between them.
The classic use of this tool is when the breakout variable is a list of products we want to compare with each other to analyze their strengths and weaknesses relatively to the target variable. In the example we use, the breakout variable (Product) represents a range of perfumes and the target variable is the Purchase Intent of these products. Other variables that will be analyzed in relation to the target represent the qualities of these perfumes.
The translucent nodes are not taken into account in these analyses.
For each state of the breakout variable, the algorithm will create a network with the same structure as the original network and with a database containing only the lines corresponding to the current state. The probability tables are learned with these new data. Then the selected analysis is performed on each network.
The following panel lets you define the parameters of the analysis.
- Breakout Variable: you can choose from a drop down list the variable that will be used as selector node. The target node is excluded from this list.
- Analysis allows choosing the analysis among:
- Mutual Information: compute the conditional mutual information between each variable and the target
- Total Effects: compute the Total Effects of the variables on the target
- Standardized Total Effects: compute the Standardized Total Effects of the variables on the target
- Linearize Nodes' Values: by checking this option, the values associated with states of nodes are recomputed and sorted in order to have a positive increasing impact on the value of the target variable.
- Regenerate Values: by checking this option, the values associated with states of continuous nodes are re-computed from the data in each database for each state of the selector variable. If the linearization is requested, it will be done after the generation of values.
- Output Directory: allows specifying a directory in which each network corresponding to each state of the selector will be saved.
The display of the results takes the form of points positioned on a 2D chart. It is similar to quadrant chart in the report or in the report.
The points represent the variables. If a node has a color then the point will be displayed in this color. The name of the node is displayed at the right of the point. When moving the mouse over a point, the coordinates are displayed in the top panel. The top panel shows the number of points displayed as well as the evidence context. It is possible to zoom in the chart as in the .
The mean value of the nodes is displayed along x-axis and the reult of the chosen analysis is along the y-axis. The title of the chart indicates the performed analysios and the current state of the selector node. the states can be selected via the chart's contextual menu.
The chart's contextual menu allows to :
- Display the comment of the nodes instead of their name
- Display the long names of the states
- Display the scales
- Select the state to display by choosing one in the proposed list
- Copy the chart as image or array of points (text or html)
- Print the chart
The chart above represents the value of each node according to the chosen state. When we move the mouse over a node, other nodes disappear and the values of this node for each state of the selector are displayed. In the example, the relevant node is "Tasty" for the state 8 of the selector node "Product". Other values of "Tasty" are displayed with the name of the corresponding state next to them.
When choosing the option Display Scales from the contextual menu, chart displays for each node a scale between the minimum and maximum values among all states of the selector. The mean is also indicated by a vertical line. It is therefore possible to easily identify where is the value of the node for the current state among all other states. So we can identify the possible negative and positive progress margins for the current product for each of its qualities.
By hovering the mouse over the point, we obstain, as previously, the different values of the node for each state in addition to the scale:
The button Export Variations allows exporting the percentages of negative and positive variations of each node in order to use them in other analysis thanks to the .