Paragraphing will differ with every type of writing you use. In the expository essay, paragraphs are generally well-developed statements, at least seven sentences long. But they can vary greatly. Remember the basic rule: a paragraph represents an individual idea. But beyond that, you as the writer have a lot to do with what constitutes an individual idea. Try to think in terms of helping your reader understand the info you are providing. In essays, a bunch of short paragraphs can be somewhat distracting for an audience that wants lots of explanation. In other types of writing, short paragraphs are a blessing for people who want to finish reading quickly.
I’ve always been a supportive of the basic essay format: an introduction; a body; and a conclusion. The introduction and conclusion, I feel, need to be succinct- to the point. So they are generally shorter than other paragraphs. The body, I feel, is more successful with an adequate amount of support. As I’ve said many times, three paragraphs of support seems to be sufficient. If each paragraph is seven to ten sentences long, then a standard essay would be about 1 1/2 pages long. Of course I don’t like counting words, so I obviously am not in support of counting sentences and paragraphs. But make sure each section in your essay (a paragraph is a section) is developed to a point that will help your reader understand and feel satisfied with the information.
The following excerpt is from a novel written by Charles Dickens. It is actually several paragraphs long, but I’ve written it as one large paragraph. See if you can decide where the paragraphs should be placed, and why.
It touches me nearly now, although I tell it lightly, to recollect how eager I was to leave my happy home; to think how little I suspected what I did leave for ever. I am glad to recollect that when the carrier’s cart was at the gate, and my mother stood there kissing me, a grateful fondness for her and for the old place I had never turned my back upon before, made me cry. I am glad to know that my mother cried, too, and that I felt her heart beat against mine. I am glad to recollect that, when the carrier began to move, my mother ran out at the gate, and called to him to stop, that she might kiss me once more. I am glad to dwell upon the earnestness and love with which she lifted up her face to mine, and did so. As we left her standing in the road, Mr. Murdstone came up to where she was, and seemed to expostulate with her for being so moved. I was looking back round the awning of the cart, and wondered what business it was of his. Peggotty, who was also looking back on the other side, seemed anything but satisfied; as the face he brought back into the cart denoted. I saw looking at Peggoty for some time, in a reverie on this strange case; whether, if she were employed to lose me like the boy in the fairy tale, I should be able to track my way home again by the buttons she would shed.
Of course, this is a narrative sample. We learned way back that narrative essays will usually have shorter paragraphs, but still, there needs to be logic behind where they should be. I will let you know, shortly, where Lewis had his paragraph breaks. See how close you were to what he wanted. Differing doesn’t make you wrong though, as long as you have a reason for the break.