SMCE window

Criteria tree viewer

The criteria tree viewer shows you the contents of a criteria tree. With the criteria tree viewer, you are able to insert and remove constraints, factors and/or groups of factors, associate input maps to criteria, edit labels and start dialog boxes for standardization and weighing. The criteria tree viewer consists of one criteria tree column and one or more alternative columns.

Creating and filling a criteria tree

Criteria tree column:

The criteria tree column, i.e. the first column, displays your criteria tree.

A criteria tree may contain:

	Main Goal	One main goal is obligatory for any criteria tree. The main goal is also called the main root.
	Constraint(s)	Constraints can only appear directly under the main goal.
	Benefit Factor(s)	Factors may appear directly under the main goal or under a group of factors.
	Cost Factor(s)	Factors may appear directly under the main goal or under a group of factors.
	Group of Factors	A Group defines an intermediate or a partial goal. Under a Group, you can add one or more Factors and/or other Groups of Factors. Click the plus sign in front of a Group of Factors to expand the group.

Tips:

• To insert new groups, factors or constraints:
• make sure you are in the Problem Definition mode,
• select the main goal or a sub goal under which you wish to insert a new group, factor or constraint,
• use the Insert command on the Edit menu.
• When dealing with a large number of factors, it is best to divide them into groups of factors. A group of factors is usually linked to a particular goal. If necessary, the groups can be divided even further. When designing this kind of hierarchical structure, it is important to maintain a balanced distribution of the factors over the groups of factors.

Alternative column:

In an alternative column, i.e. the second column and any other next column, you can:

• associate input maps to criteria, and
• specify names for the output map(s), i.e. the composite index map(s).

The number of alternatives is 1 when performing Problem Analysis or Design of Alternatives; the number of alternatives is greater than 1 when performing Decision Making. The SMCE application can handle a maximum of 9 alternatives.

Tip: To set the number of alternatives, use the Alternatives command on the Edit menu.

Visual feedback (background colors)

When building the criteria tree, adding input maps (or columns) to the criteria, specifying the output map name for the main goal and optional output map names for partial goals, and specifying the standardization and weighing methods for all criteria, the application gives you some visual feedback on your progress.

The application thus automatically evaluates the criteria tree against some completeness restrictions and warns the user accordingly.

Items with a red background color indicate incompleteness, for instance:

• no output name was defined for the main goal,
• a group was defined, but no children were added to the group, or
• an item was not standardized or weighed yet.

A green background color means that an output map name is expected:

• for the main goal, an output map name must be specified.
• for a partial goal, an output map name is optional.

Tip: To edit an existing name of an output map, select the output map and either slowly click the map name again, or use the context-sensitive menu, the F2 key or the Enter key.

When all necessary steps are completed, output maps can be calculated separately (Generate Selected Maps) or all output maps can be calculated at once (Generate All Maps).

Note: Specifying an output map name for a partial goal, is optional but recommended in order to gain understanding of the composition of the criteria contributions to the composite index.

Information on Standardization

As all input data has to be standardized, and as various methods of standardization are available, information on standardization will appear behind the textual names or descriptions of criteria, as soon as you have performed the standardization of a criterion.

1. Standardization of factors

Depending on the type of input data that is standardized, the criteria tree column will show some information on the standardization and the selected standardization method.

When Value input is standardized as a factor, the criteria tree column will show:

When Boolean input is standardized as a factor, the criteria tree column will show:

When Class input is standardized as a factor, the criteria tree column will show:

Examples of standardizing factors (benefits and costs):

In the examples below, 6 output maps were calculated, each time using a single factor as input. As input, a value map was used with input values between 10000 and 17250. Each time a different standardization method was selected, and an output map was calculated. This shows the effect of each selected standardization method.

Input value map Input values range from 10000 to about 17250.	Legend for standardized output values
Benefit Std:Max 0 is standardized to 0 (input value 0 does not occur); maximum input value is standardized to 1 (green).	Cost Std:Max minimum input value is standardized to 1 (green).
Benefit Std:Interval minimum input value is standardized to 0 (red); maximum input value is standardized to 1 (green).	Cost Std:Interval maximum input value is standardized to 0 (red); minimum input value is standardized to 1 (green).
Benefit Std:Goal(12500,15000) input values <=12500 are standardized to 0 (red); input values >=15000 are standardized to 1 (green).	Cost Std:Goal(12500,15000) input values >=15000 are standardized to 0 (red); input values <=12500 are standardized to 1 (green).

2. Standardization of constraints:

Standardization of constraints is similar to standardization of factors but it is not completely the same.

Depending on the type of input data that is standardized, the criteria tree column will show some information on the standardization and the selected standardization method.

When Value input is standardized as a constraint, the criteria tree column will show:

When Boolean input is standardized as a constraint, the criteria tree column will show:

When Class input is standardized as a constraint, the criteria tree column will show:

Examples of standardizing constraints:

In the examples below, 5 output maps were calculated, each time using a single constraint (distance to city center) as input. As input, value map DIST was used, representing the distance towards the city center; the input values range between 0 and about 7250. Each time a different standardization method was selected, and an output map was calculated. This shows the effect of each selected standardization method.

Input value map: distance to city center (DIST). Input values range from 0 to about 7250. White represents the city center itself.	Std:<>0 DIST <> 0 is standardized to 1 (green) all other values are standardized to 0 (red);
Std:Min=500 DIST ≥ 500 is standardized to 1 (green); all other values are standardized to 0 (red).	Std:Max=1000 DIST ≤ 1000 is standardized to 1 (green); all other values are standardized to 0 (red).
Std:Inside(500,1000) DIST ≥ 500 and DIST ≤ 1000 is standardized to 1 (green); all other values are standardized to 0 (red).	Std:Outside(500,1000) DIST ≥ 500 and DIST ≤ 1000 is standardized to 0 (red); all other values are standardized to 1 (green).

Information on Weighing

The following items can be weighed:

• multiple factors and optional sub goals under the main goal,
• multiple factors and optional sub goals under a sub goal.

By weighing the factors and optional sub goals under the main goal, the relative importance is determined of all the factors and sub goals that are part of the main goal.
The same goes for the factors and optional sub goals under a sub goal.

Information on assigned weights and on the selected weigh method(s) is shown in the first column, i.e. the criteria column. Constraints cannot be weighed.

After weights have been assigned, the criteria tree column shows the following:

• The selected weight method is shown after the group name (selected main goal or selected sub goal).
• The assigned weight values are shown in front of the criteria names (factors and groups of factors) that occur under the selected main goal or under the selected sub goal.

In the criteria tree viewer, this looks like:

For more information, refer to SMCE window : Weigh or refer to SMCE window : Weigh methods (additional info).

Other functionality

To change the width of columns:

To change the width of the criteria tree column or an alternative column:

• position the mouse pointer at the end of a column,
• the mouse pointer will change into a double-sided arrow,
• drag the mouse pointer to the right to make the column wider, or drag the mouse pointer to left to make the column narrower.

See also:

SMCE window : functionality

SMCE window : toolbar

SMCE window : status bar

SMCE window : menu commands

ILWIS objects : criteria trees