Hi Solomon, the parameter of inputsum is used when the value of a input field is edited in front-end.
In example, if you had a teble with only Dept and Mark2, and you edit the value in Mark2... How will be distributed the value you entered between the different 'Name'?
Try it with a pivot table setting Dept and Name as dimensions and inputsum as expression. Collapse the Dept. change the value of the input field and expand again the Name to check the distribution it makes with the different parameters.
It can be based on the different values, on number of records for each value, same value for all records...