For the proofreading of my thesis I've used the help of a paid lector. My question is, if it's normal practice to include this person into the acknowledgements of the thesis?
I acknowledged my two volunteer proofreaders, but probably would not acknowledge a paid lector unless he went above and beyond what the fee covered.
In the case of acknowledgments, I think a safe rule is if you're not sure, put it in. After all, you could type, "Thanks to Jane Doe for proofreading," faster than asking this question.