513. The skilled addressee.

The sufficiency of the directions depends on the presumed skill of the person to whom the specification is addressed1, namely the person who is expected to carry the invention into practice2, and he will be presumed to combine a reasonable amount of common sense with a knowledge of the technical area or areas to which the invention relates as they existed at the date of the patent3.

The nature of the invention determines the level of sophistication required of the skilled addressee. For example, in the case of an elaborate scientific process the addressee may be presumed to be a