Practical implications

During the evaluation of an expression, it will never be necessary to backtrack the evaluation process in order to reach a normal form.
- There are no blind alleys in the evaluation of an expression
An expression cannot be converted to two different normal forms (modulo alpha conversions, of course).
If an expression e somehow can be reduced to f in one or more steps, f can be reached by normal-order reduction - but not necessarily by applicative-order reduction

Normal-order reduction is more powerful than the applicative-order reduction

Scheme and ML uses applicative-order reduction

Haskell is an example of a functional programming language with normal-order reduction