A professionally-finished manuscript requires a professional proofreader. Whether your text will be published on a web page, submitted to an external examiner or sent to the printers, quality proofreading will highlight the errors. It’s invaluable.
This is the final step you’ll take before publishing. While copy-editing attends to major flaws of standardization and spelling, your work also requires proofreading. This stage is essential: it’s the final quality check, the final smooth-over, the final scrutiny. I can’t over-emphasize the importance of proofreading your work before sending it to print or submitting your thesis.
It’s always tempting to proofread your own work but, after working on a manuscript for any length of time, our brains get used to the errors and we just don’t see them anymore. We can read and re-read the text and still overlook common spelling mistakes or missed punctuation. We can’t rely on the computer spellchecker, because they make mistakes too. You might mean to say, “The man was exhausted,” but type “the man saw exhausted” instead. The spellchecker can’t see the difference and its default spelling is American (honor/honour, color/colour). Sadly, a missing comma could change the meaning of your sentence altogether.
It’s the little things that count. The crossing of a t and the dotting of an i.