"Concise" means to give the most information with the fewest words. It is not about sentence length A long sentence can be concise, and a short sentence may have too many words.
Conciseness means that you use the best amount of language—not too little, not too much—to describe what it is that you are saying.
There are several points to be careful about:
- Unusually long expressions: instead of "the person I have known for many years and like very much," use "my old friend." Instead of "the meal I eat every morning soon after waking up," just use "breakfast."
- Unnecessary information: Instead of "the final exam which my teacher gave all the students in the classroom at the school," just use "the final exam." The reader knows final exams are given by teachers in classrooms in schools; adding that information is not necessary.
- Repeated information: you may be surprised how often the same information is repeated. Avoid it!
Here is a real-life example of student writing:
When he graduated from high school, he moved to Tokyo to enter the restaurant the age of 18. Since he started working at the restaurant, he really worked hard.
Notice that in the above writing, three pieces of information are repeated: (1) the person's age, (2) the type of job, and (3) the idea that the job was new.
"When he graduated from high school" means he is 18; it is not necessary to give both pieces of information, unless the person graduated at an unusual age.
The word "restaurant" is used twice. Only once is necessary.
The writing states that he "enter[ed] the restaurant [job]" and that "he started working at the restaurant." These also mean the same thing.
The same details could be expressed this much more concise way:
When he graduated from high school, he moved to Tokyo and worked long hours at a restaurant.
"In Other Words" = "My Previous Sentence Was Bad"
Here's another clue: if you use the expression "in other words," or when you have to explain what a previous clause or sentence means, it is a sign that you wrote the first statement poorly. Don't add clarification to a bad sentence; instead, delete the poorly-written statement and rewrite it better. (It is possible to use "in other words" only if you are explaining such a complex topic that more than one explanation may be required.)
The lesson: look at your writing carefully to find and remove any words which repeat information or are not required. Preferably, you should then add specific details you did not express before. "Concise" does not mean only "short"; it means being as meaningful as possible with the fewest words.