Based on four characteristics and five evaluation levels on a scale of ++ to – – (also: +2 to -2), the operating instructions, maintenance information or manual are subjected to a text check. You can check the intelligibility of your text using the following four characteristics:
- Simplicity: Check if sentences are too long – no more than 9 to 13 words – and if the text contains foreign words that need to be explained. The text is written clearly and precisely.
- Structure and organisation: This has to do with the logical organisation of content and having a clear structure, e.g. through formatting, structuring, numbering, etc. which help to hold the reader’s attention.
- Brevity and conciseness: A must in technical documentation. Keep in mind that only what is necessary should be described, but do not be over-concise. If the text is too short, understanding may be affected.
- Extras to add interest: Make the technical documentation for your product appealing using graphics, illustrations or examples. Ensure that you address the reader, user, operator or installer personally.
If you are not sure whether all these criteria have been satisfied, simply do a cross-check. If the text slips into the minus area following critical evaluation of one or more of these criteria (see figure above), it should be revised.
For the sake of completeness, we would also like to point to the Karlsruhe comprehensibility concept by Susanne Göpferich, which later emerged as the Hamburg model and includes additional features such as correctness, perceptibility, communication aspects, etc. However, since we view the Karlsruhe concept as a more in-depth addition to the Hamburg model, we will not go into this in more detail at this point.