I see from the image in the correspondence with Steve you are using the percent weighting method. In the Suitability Modeler, when you specify weights as percents, we multiply the criterion values by the identified percent. That is, if the weight for a criterion is 25%, we multiply each value in the input criterion by .25.
Why does your minimum value not equal 1? Let’s say you have three input criteria. The percent weights you have specified for the 3 criteria are 25%, 25% and 50%. For a particular cell location, the value for each criterion are: criterion 1 = 1, criterion 2 = 1, and criterion 3 = 1. The final suitability value for that cell will be 1 * .25 + 1 * .25 + 1 * .5 = .25 + .25 + .5 = 1.
But then let’s say for another cell, the values for the criteria are (1, 3, 1). The final suitability value for that cell will be 1 * .25 + 3 * .25 + 1 * .5 = .25 + .75 + .5 = 1.5.
In the Suitability Modeler we output the actual weighted sum value from the percent weighting. In your situation, you probably have no location in your study area that has all 1’s for each criterion, therefore the minimum will not be 1. This same logic holds why your maximum value in not 10; you probably have no locations that have all 10’s.
However, if you are familiar with the Spatial Analyst Weighted Overlay tool, the actual weighted sum values are linearly transformed (in this case stretched) to the evaluation scale (the suitability scale). As a result, the range of the output is the same as the suitability scale being used for the transformations.
We suggest using the actual weighted sum values but from this discussion, we may add a check box to the Suitability tab indicating whether you want us to normalize your values to the suitability scale. You will then have a choice to do either.