This means the words/phrases that you are going to use with high frequency [ i.e. very often ] in your essay/dissertation/thesis.
If you are writing a long academic document and you frequently mis-spell or mis-use a word/phrase, then your marker/supervisor is going to think, “This student hasn’t even bothered to get the basic right!” Believe me, when you are marking a 15,000 word dissertation on “E-commerce in the USA” and the student has written “USA” instead of “the USA” at least 50 times, you get annoyed!
Examples of high-frequency vocabulary
Names: of people, or places, or organisations. Think about nationalities too: Britain is the country, British is the adjective.
I once had to mark a Public Relations dissertation about a famous chef’s business empire-the student spelt his name incorrectly right through the dissertation! That wasn’t good PR!
Tip – double check the spelling of names that you will be using, and look in the dictionary for adjectival forms of nouns e.g. Economics/Economic.
Your title: amazingly, many students either copy their assignment’s title incorrectly, or they write the title of their dissertation incorrectly, and end up repeating the same phrase incorrectly a hundred times in the next 15,000 words.
Tip – double check that you have copied your assignment title correctly. If you have written your own title [ e.g. for as dissertation ] ask your Supervisor or an native speaker of English if the title is written in good English.
Terminology: every academic subject has specific terminology which you will be using frequently. For example, Business students will often need to use the word “economy” in their writing. This is a noun, and students guess that the adjective for “economy” is “economical”. But “economical” means cheap/not expensive! The correct form is “economic” e.g. “there are many economic reasons for…”
Tip – check these word forms in a good dictionary.
Collocations: these are words that always “go together” e.g. to conduct research” or “to do research”. We never say “to make research”.