# Can two or more splits in a binary decision tree be made on the same variable?

My question is about a binary decision tree (binary to integer).

Is there any problem if the conditions defined on a same variable ex. x1? I mean when i define the variables for my tree, can I choose:

if(x1>3)
then
if (x1>4)
then ....
else
....
end
else
....
end


as you see my variable is always x1, but the conditions are different. In all binary decision tree that I find on the net the variable changes!

• In trees, the program chooses what variables and levels should be used for splits; that's part of the point. If you only included x1 in the model, then it would be the only variable used, but the program would still choose the splits. But if you only have one variable, trees probably aren't needed. Oct 24 '12 at 12:24

• What about the exact same split (x > 4 for example) on different branches? Or does a split generally not apply to both the yes an no sides of a previous split? Sep 23 at 15:53