Casual writing in the popular mainstream style is usually very different from the type required in academic settings. One is largely loose and informal, while the other is more conventional and strict. Whenever you write in either style, being mindful of these differences is necessary to keep the material consistent throughout its course.
Contractions. In academic writing, you need to spell out words; in informal writing, you’re free to use common contractions.
Technical terms. In academic writing, the use of technical terms is expected, provided you offer up an accompanying running definition; in popular writing, the use of technical terms should be kept to a minimum, with an in-depth explanation every time.
Groupspeak. In academic writing, you should use “we” when explaining technical terms; during informal use, using specific names (as well as referring to yourself in the first person) are more acceptable.
Abstractions. In academic work, you’re encouraged to emphasize abstractions, with no need for an in-depth explanation; in popular writing, any mention of high concepts should be accompanied with plenty of examples and simplified diagrams.
Passive voice. Using passive voice is actually advisable for academic writing in some cases (when trying to demonstrate that other scientists can accomplish the same results, for instance); in popular writing, passive verbs should be avoided like the plague.
Confidence. In academic writing, you are advised to state your points forcefully, in as succinct a manner as you can; for less-stringent writing, you should hold back on the self-assured statement, showing empathy for the readers’ potential struggle with it.
Most of the best writing software around integrate a facility to check for adherence to formal writing standards. Make sure to take advantage of it when you’re tasked to write in an academic capacity.