Identification Difficulty

Stuart Ball and Roger Morris devised five categories of identification difficulty:

1. Can be identified by sight in the field (with practice and experience!).
2. Can be identified in the field with careful examination. This often requires temporary capture and examination at close range, possibly requiring the use of a hand lens.
3. Cannot be identified in the field. Requires more detailed examination of a specimen with good lighting and magnification. This usually means a dead specimen under a binocular microscope.
4. Difficult to identify. Requires considerable experience and often benefits by comparison with other specimens from a reliably identified collection. Less experienced recorders should retain voucher specimens and seek verification by an expert.
5. Very difficult to identify. Will normally require voucher specimens submitted for at least a second opinion from other experts.

Ball & Morris, 2024¹ used a version of this with categories indicated by icons shown in the species accounts:

1. 
2. 
3. - 5

They also categorised species by the likelihood of being able to make an identification from a photograph.

• Identifiable in the majority of cases from good photographs.
• Identification often possible using a suite of good photographs (top-down, side-on and head-on).
• Identification unlikely to be possible from photographs.