comparison by (assumed) percentage of nearness between prediction vs actual

A1 = Computer prediction : automatically generated
B1 = Teacher prediction : may be blank or may have value
C1 = Actual Score : input

=1-ABS(C1-if(B1="",A1,B1))/C1
click button format in %
hope i understand your question correctly.

"Martin B" wrote:

Hi

Hope someone can suggest a solution to this apparently simple problem.

I am developing a spreadsheet to evaluate student performance. In one cell a computer predicted score is automatically generated, the teacher may or may not enter their predicted score in the next cell. Finally the actual score is entered in a third cell.

I need a formula to compare the actual score with the computer generated score unless there is a value in the teacher prediction cell in which case I want to compare that one.

A1 = Computer prediction
B1 = Teacher prediction
C1 = Actual Score

so if B1 is blank, compare C1 to A1 however if there is a value in A1 and B1, compare C1 to B1

Hope this makes sense

Thanks in anticipation

Martin