#Python 2, 53 52 50 bytes
Python 2, 53 52 50 bytes
Expects input enclosed in quotes, e.g. "watch"
As unnamed lambda:
lambda s:(sum(map(cmp,s[1:],s))+1)/min(len(s)-1,3) Sums the sign of difference between each letters and integer-divides by len-1. If all were 1 (increasing) the sum is len-1 it displays 1, similar for decreasing -1 and for mixed 1,-1 the sum is smaller than len-1 so it displays 0.
-1 byte for changing cmp,s[1:],s[:-1]) to cmp,s[1:],s)+1