As you know coherence and Unity are the two key elements for a successful essay. But honestly I can’t find a clear-cut distinction between them, and I feel that they are almost the same.
Unity means oneness and we should not be led astray from the main idea and talk irrelevantly which does not support the topic.
Coherence means that with the help of transitions and clear explanation of each idea in our writing we try to create links which help the readers move smoothly from idea to idea within the paragraph.
Can you illustrate the difference between them so that I have a better and clearer concept?
My second question, the word “concept” I used above is so close in meaning to “conception”. How would you briefly demonstrate their subtle difference and usage?
Hokay… Trust you to ask the complicated questions!
First - I am NOT a teacher, and I do NOT remember the correct terms for all of the years of English I took as a student.
However, I was a darn good English student. 
First, the difference between “concept” and “conception.” Briefly, a concept is an idea, one singular item. Conception is the process of thinking of that idea, or of thinking of an idea (you don’t have to have come up with the idea yourself) Conception is also is the word for creating life through the act of sex. 
Now that the easy stuff is out of the way.
Unity and Coherence.
Unity means: every part of your essay should contribute towards the topic at hand.
Don’t add sentences or paragraphs which are tangental (slightly related) or orthagonal (not at all related) to the topic. Stay focused on the subject you are trying to convey. Everything you mention should be towards the purpose of furthering your idea, or explaining your topic.
Coherence means: choose an established essay-writing method, and follow it clearly.
There are a few basic essay-writing methods, but without knowing which one you use, I can’t really be of much help here. If you have directions about what to accomplish in each paragraph, or in what way to structure your argument on paper, those are the instructions related to coherence. You are trying to build a logical and organized paper, by following the rules established by whatever method you are following.
As to how they are related:
You can be unified without being coherent if: Everything you write is ABOUT the selected topic, but it is unfocused and not organized well.
For example, if I chose to put half of the explanation about “concept” and “conception” down here, instead of both halves together at the top, I am still unified - covering the topic, but I am not coherent - I am harder to understand.
You can also be coherent without being unified if: Everything you write is organized and understandable, but it has nothing (or very little) to do with the topic you are supposed to cover.
For instance, if I here started talking in detail about the structure of 5-paragrah essays (a particular method of essay writing), I would still be coherent - you would understand my sentences. I would not still be unified, because I am no longer on topic (general, not specific, essay help).
That make sense?
It most certainly does not!
What Reza says in the OP about coherence is a lot more to the point. Coherence means hanging together and making sense. I suppose an essay might be said to have unity but not coherence if every sentence (or paragraph) was relevant to the topic, but if no other connection between the sentences (or paragraphs) was apparent. if they just seemed to be thrown together at random. The relevance of each sentence (or paragraph) to the one before it should be apparent, and, ideally, the essay as a whole should constitute a single, connected argument.
Following “an established method” may improve a poor or inexperienced writer’s chances of writing a coherent essay but it is neither necessary nor sufficient. It is perfectly possible to write coherently without using, or knowing anything about, any such methods, and most of the best, most coherent writing will ignore them.
In other threads, Reza has commented that they are using a textbook, and I disagree with you that a textbook will not provide a framework device or expect a student to follow a specific type of structure.
In addition, as a self-directed student of English, I would say that Reza qualifies for the “inexperienced” caveat of your comment, despite his/her pretty amazing language abilities.
For someone who isn’t familiar with American style schooling and what is therefore expected (often on an unconscious level) by professionals who are used to dealing with the products of said schools, I stand by my comments that sticking to an established framework is a good place to start.
Now, I will say that you are otherwise correct, and anyone writing as an adult on their own with full mastery of the language and the conventions of that language should be able to write coherently without a framework, and often will be hampered in their expression by adhering to one.
Just because a master doesn’t need one, and would be limited by one, doesn’t make a framing or structural device of any lesser use to a student who doesn’t have that same experience.
I would define them by example first:
Neither coherence nor unity:
“There are lots of colors. The sky is blue. My blue car has 20,000 miles on it.”
Unity, but poor coherence:
“There are lots of colors. The sky is blue. My car is a different blue.”
Coherence, but poor unity:
“There are lots of colors. For example, my sky-blue car, which has 20,000 miles on it, is a different shade of blue than a beautiful summer sky.”
Unity and coherence:
“There are lots of colors. For example, my sky-blue car is not exactly the same shade of blue as the sky on a beautiful summer day.”
Unity is mostly about the meaningful content of what is said. You want each fact, statement, argument, etc. to be working toward a common purpose. In the above examples, the 20,000 miles fact just doesn’t contribute anything to a discussion of color and that’s why those are not unified. The car is only relevant as an example of color, not based on mileage.
Coherence is more about the way things are said and organized, not so much about what is being said. The short, choppy sentences in the first two examples contain most of the information of the later sentences, but provide fewer cues to the reader to help them follow your train of thought. On a large scale, coherence can be helped by following some kind of outline - introduction, paragraph 1, paragraph 2, conclusion.
(I am a college English teacher)
It sounds like the OP is working from a textbook I’ve used in the past (by Langan, maybe?) which lists the “Bases” (like baseball bases) of effective writing. Going from memory, they were Unity, Coherence, and Sentence Skills.
A unified academic essay will normally establish a clear thesis and then support it, without going off on tangents. At this level of writing, the thesis statement is the most important central detail of the essay as a whole, and the ‘evidence’ used to support the thesis must, in fact, support that thesis.
A coherent essay, according to Langan’s textbook, will stick to an established mode of organization–almost always chronological, emphatic, or spatial. In that sense, I tend to agree with Lasciel–even established non-fiction writers are almost always going to follow one of those modes. Do good writers have the freedom to subvert the rules, even at the ‘sentence skills’ level? Yes. There are stylistic reasons, of course, for writing a sentence fragment, and even for having a sentence fragment be an entire paragraph unto itself.
Like this.
And, of course, there are times when it is perfectly acceptable to lead a sentence with a conjunction. Or to randomly split an infinitive. In my own writing, sometimes I find a preposition to be a perfectly valid word to end a sentence with.
But, at the high school/college level of writing, it is important to first establish that the writer knows the rules before breaking them. In terms of essay coherence, that means selecting, say, chronological order and then using key transition words like “first, second, then, later” to make that organization apparent to the reader. It’s kind of like learning the periodic table before balancing chemical formulas.
Coherence may mean that all the parts in a piece work together. In this sense it means much the same as unity.
But coherence also means that the piece is clear and understandable. In this sense, coherence is the opposite of incoherence.
As an illustration, consider this passage from Coincidence and Counterfactuality: Plotting time and space in narrative fiction by Hilary P. Dannenberg:
It has unity- it’s about one subject. But it lacks coherence.
You do not disagree with me, because I never said anything about textbooks.
I will repeat, however, that “coherence” most certainly does not mean “choose an established essay-writing method, and follow it clearly.”
I certainly accept that a novice writer might be well advised to use such a “method” (especially if their teachers expect them to), and that it might help with maintaining coherence, as well as with other aspects of essay writing. I already said as much in my original post.
Let me now add, however, that even better (and more generally applicable) advice to a novice writer would be that they should take care not to attribute views to other people that those people have not expressed, and they should pay close attention to the meanings of the words they use (including the word “means” itself).
Incidentally, it is also not true (although, again, it may well be that people learning to write are well advised to act as though it were true) that one needs to know the “rules” of essay writing before once can break them. Most of the best essayists never heard of such rules or methods, which are a recent invention of educators. Do you think that Montaigne first learned and practiced the rules of essay writing, and then decided that he was talented enough to ignore them? Personally, I never heard of these rules until a few years ago, when I learned about them from my daughters who were being taught them in elementary and middle school. I was never taught them myself; neither, I think, was anyone else of my generation. Despite that, I and many of my contemporaries know how to write a coherent and unified essay.
Vis-a-vis the “rules” (which, as we all know, will vary some by style manual) I think we’re approaching it from two different angles. My job in Composition I isn’t to produce artists–it’s to establish a set of expectations for the next few years of their academic careers. As such, they must, IMHO, learn the very basics of what academic writing is about.
I am not a prescriptive linguist, and I generally only emphasize the most important grammatical rules to my students, but the ability to write a complete sentence is important. Unfortunately, about 75% of my freshmen cannot recognize or identify a complete sentence reliably (because, usually, they have no concept of a ‘subject’ or ‘verb.’) A higher percentage do not understand that it is grammatically incorrect to join main clauses with only a comma. I have yet to have a student define, during a class discussion, what “passive voice” is.
I’m a fairly recent graduate (finished high school in '99) and this was information I was taught early, but for whatever reason, my students either aren’t getting it or aren’t retaining it. I don’t know why. At any rate, I can’t in good conscience send them on, into upper-level courses where a substantial part of their grade will be a term paper, without trying to teach them that “He go to the movies” has a disagreement between the subject and verb. It’s difficult enough to think critically about a topic, generate a thesis, and support your thesis. Add in a complete lack of understanding about unity, coherence, and sentence skills and even a professor in a non-English class will fail the paper (and justifiably so.)
Though you’ll find this sentiment in many sources, I’ll refer to Purdue’s Online Writing Lab, which is perhaps the most commonly-listed website in composition courses:
“Coherence is the trait that makes the paragraph easily understandable to a reader. You can help create coherence in your paragraphs by creating logical bridges and verbal bridges.” Link
“Easily understandable to a reader” will normally mean, at a minimum, that a pattern of organization has been established and the author is following it reasonably well. Those “verbal bridges” include key words and transitions.
I understand an objection that writing is difficult or impossible to nail down to a template, and I agree with that, but formal academic writing–up to and including a thesis or dissertation–has fairly strict organizational requirements. They’re arbitrary sometimes, but they are there for a reason. I’d submit that the scaffold is there because we’re less interested in the writing than the critical thinking–the ideas. The exact manner in which those ideas are expressed can certainly be eloquent, but it’s window dressing. I’m not shooting to make great writers. I’m shooting for good writers in a world full of bad ones.
I missed the edit window, but I remembered a point I wanted to make.
For myself, never in my college career did I ever have to consciously think about unity, coherence, sentence skills, etc. I guess I just naturally knew that “this looks good, that looks bad” and that served me well. Until I started teaching, I didn’t think that was unusual. But it is–it’s rare enough that I might have one student out of thirty who has that ability. The rest really have to focus and work hard just to attain the minimum standards.
I have not received and started to grade the first essay this term, but my cousin is in Comp. I at a competing institution, and 21 out of 24 students in her class failed the first essay. Her failing grade, fortunately, was all grammatical, which is easier to correct. But the sad fact is that, at least in this neck of the woods, it’s not a statistical abnormality.
outlining to me is the best way.
For the purposes of someone trying to imitate or follow the directions of a specific textbook, yes it most certainly does mean exactly that. I’m sorry that you disagree, and I will not be debating with you further about this.
You are obviously a skilled writer, and I am glad to know that you never knew or, nor needed, any framing devices to aid your own natural writing abilities.
Please understand that sometimes, some other people may not share your innate ability, and that advice given to a specific person in a specific circumstance does not need to apply to everyone in all circumstances.
For clear and polite recounting of my opinions on the subject of framing and organizational methods in essay-writing, please see BlakeTyner’s two preceding posts.
And we all know that the process of defending a thesis isn’t an essay, correct? An essay is an organized exploration of a topic, whereas a thesis defense is essentially what a lawyer does in the courtroom, complete with the restatement of the thesis (the closing arguments) at the very end.
Lasaciel,
Thank you,
From what you advised, I conclude that if there are ideas irrelevant to the topic sentence, then there’s no unity, and if all the ideas and explanations are relevant to the topic but are located in the wrong order then there’s no coherence. Right?
May I add something? But when you put an idea and wish to explain more about it in fact even the irrelevant explanations may not be directly concerning to the topic, but it is somehow contributing to it.
Example:
Jack is one of the main distractions who is always noisy and messy. Yesterday when I decided to focus on my math exercise which the unit I was reading was about differential issues, he played his favorite rock CD loudly for about half an hour, then he started moving recklessly in the room from corner to corner throwing his things here and there …
Some may consider the blue part irrelevant to the topic (My distractions when I want to study), but I feel that this sentence can be one of the main elements for a topic sentence which they are (Statistics, examples and an statement by an authority). And here this small example of what the writer studies can give the reader a better picture of the situation. This is the way that the author can persuade the reader to agree with him.
What do you think?
Dracoi, njtt, Black Tyner
Thanks a lot. Your comments were a great help.
Little Nemo,
Thanks for the comment.
Maybe because the sentence is too long?
Njtt, # 8
I understand you when you say, other people may write well without the help of these rules because they have the talent of the job. I think introducing and presenting these rules is not going to object to your statement or opinion, but wishes to help the untalented ones how to approach a good writing style. More to it, if I have to write and read for 5 years and then learn how to write very well, some people (educators), believe that there are helpful advice and rules which they can act as a shortcut to learn how to write very well sooner than 5 years.
Black Tyner, # 9
Thanks for the link. It’s great.
Without looking those words up I’m going to wing it.
To me, coherance means it must make sense, a logical flow.
And a concept is an idea while conception would be creating a thing.
(From the dictionary in my mind. FWIT)
Now I’ll go back and see what everybody else said.
Lasciel, your defintions are great; you were a VERY good English student. But when you were describing “unity” I thought, “Boy, that wouldn’t work in the country.” (No tangental incidentals?) If we screamed, "Fire! (or wrote about it,) we’d pause and tell you whose cousin set it, and why. (He didn’t mean to.) I guess speaking only for myself, if I can’t throw in the “color” on the page it’s almost impossible for me to write. But I’m learning something from the posts and love to read and talk about writing. Thanks.
Reza, in regards to going off on tangents, I’d say it depends on two things.
Firstly, how well you can tie that tangent into the rest of the essay topic.
Let’s go with Jack and his interruptions. Here’s an example topic: Jack is a bad roommate.
Jack’s interruptions are causing me difficulties in class and I want a new roommate. I have to have peace and quiet to study, especially in harder classes. For example, I have Differential Equations in math right now, and it is really hard for me to learn. Jack’s interruption last week was especially badly timed because it made it impossible to study hard enough to pass my test, and I failed. Now I have a bad grade in that class. I think that Jack should have to move to a different roommate who does not need quiet to study.
In this paragraph, it isn’t really necessary to know the specific subject that you were interrupted in, but it adds flavor to your argument, and can make people more sympathetic to you (you could be appealing to other people who find math difficult, for example). The text in red can be removed and your paragraph still makes sense, but it’s not as strong an argument without it. Because your paragraph makes sense without the sentence in red, that means it is still a tangent, but here it is a useful tangent. It contributes towards your topic = convincing someone in charge to let you have another roommate.
Here’s another paragraph. Topic: I don’t like my roommate, Jack.
My roommate Jack is always interrupting me and having parties in the room and generally being a pain in the ass. I really wish he would get a new roommate and leave me alone. Just the other day, I was trying to study for my class in differential equations in math, because it’s really hard for me, and I really need to study hard for it, and he barged in and demanded to know if I had a bottle-opener so he could get his beer open. I couldn’t believe that he was interrupting my differential equations study for a bottle-opener! Doesn’t he have any manners!
Now here, the subject is Jack, and how you can’t stand him. All of the red text can be totally eliminated, and the paragraph is equally strong, and perhaps stronger, because it is more tightly focused on your dislike of Jack. Here, because your topic is how much you don’t like Jack, the subject you were studying when he interrupted isn’t helping further that topic - it’s distracting from it. It doesn’t help further your topic, so it is an example of a badly used tangent.
Does that help at all?
And yes, as Becky said, tangents and side-notes can add a lot of color and can at times be very interesting. It’s just important to make sure that you use them in a way where they help your topic, rather than distract from your topic.
If in doubt, leave tangents out. If you can leave it out and your topic will still make sense and be supported, then you are fine without it. If you do take it out and your topic feels weaker, then it might not have been a tangent, or it’s a useful tangent, and you can put it back in!
Hate double-posting, but I forgot to explain the second point.
Like Becky said, tangents can be very useful as FLAVOR text. If it’s not necessary, you can still use a tangent or an unrelated bit of information to add color, illustrate a small point, create a point of interest, or otherwise draw a reader into your writing.
It is important to be careful when you use tangents this way, because for many people, unrelated points are considered a flaw in writing. If you do use flavor tangents, it can be helpful to point that out, so readers know that you know it is off-topic, but that you are including it on purpose. Then make sure that you are very clear about the purpose for which you are including it.
(again, if in doubt, leave it out!)
For someone who uses wild tangents and off-topic points quite well in his writing, look at the short stories of Mark Twain.