Paragraph Coherence 

Once you have developed your topic sentence and the details of your paragraph, you need to check the paragraph for coherence. You need to be sure that everything in the paragraph fits the topic sentence.

Example:

(1) Not unnaturally in a city built of wood, fire was the devastation of Moscow. (2) In winter, when primitive stoves were blazing in every house, and in summer when the heat made wood tinder-dry, a spark could create a holocaust.  (3) Some of the homes had beautiful carved porches, windows, and gables, which were unknown in other part of Europe, where buildings were made of stone. (4) Caught by the wind, flames leaped from one roof to the next, reducing entire streets to ashes. (5) Moscow was also subject to terrible Russian winters, which often caused severe damage to the city’s wooden structures. (6) In 1571, 1611, 1626, and 1671, great fires destroyed whole quarters of Moscow, leaving vast empty spaces in the middle of the city. (7) These disasters were exceptional, but to Muscovites the sight of a burning house was a part of daily life. (8) So were the heavy wooden planks that covered the streets, which had become filled with mud after the heavy autumn rains.

Sentence #3 doesn't address the issue of fire. It is talking about the architecture of the city.

Sentence #5 doesn't address the topic sentence. It is talking about winter.

Sentence #8 doesn't address the topic sentence. It adds information about the difficulties experienced during heavy rains. 

Revised Paragraph:  

Not unnaturally in a city built of wood, fire was the devastation of Moscow. In winter, when primitive stoves were blazing in every house, and in summer when the heat made wood tinder-dry, a spark could create a holocaust. Caught by the wind, flames leaped from one roof to the next, reducing entire streets to ashes. In 1571, 1611, 1626, and 1671 great fires destroyed whole quarters of Moscow, leaving vast empty spaces in the middle of the city. These disasters were exception, but to Muscovites the sight of a burning house was a part of daily life.

Now each of the sentences in the paragraph fits the topic sentence and gives the readers additional details about the topic.