Ability of entry to hold up in use. Attention to details, neatness and finishing touches. Appropriate choice of materials. Evaluate the work as a whole. Keep in mind that this entry is at Intermediate Level, regardless of the skill of the entrant.
Extant pieces are ideal sources.
For pre-Medieval devices, medieval depictions are very unreliable and should be supported by text references. Explains original experiment or research. Explains any deviations or variations from period norm. OR obvious mixture of elements from different cultures or periods within or among individual pieces in the set entered. Difficulty of design, form, coordination of parts, decoration, etc.