Punctuation is vital to any document. A simple punctuation mark can say so much, and can change so much. My favourite example of how a sentence can be changed is as follows (source unknown):
An English professor asked his students to punctuate the following:
A woman without her man is nothing.
All the males in the class wrote:
A woman, without her man, is nothing.
All the females in the class wrote:
A woman: without her, man is nothing.
In transcription, incorrect punctuation can completely change the meaning of what has been said. Such a change could compromise the integrity of your data. Although you may know what was said and understand the context, the co-coder (who doesn’t listen to the audio) may disagree with the data you have found, or your dissertation or thesis may portray something different to what you believe it is portraying. For this reason, it is imperative that you select a transcription company who understands the complexities of the English language and who can translate the spoken words, meaning and all, to a typed document.
The same is applicable when you require a document to be typed, or proofread and edited.
Remember: punctuation is powerful!