B. The Topic Sentence

# videos: below the brief notes
(Notes by Huifang Peng)
1. A good topic sentence accommodates two parts/functions:
a. introducing the general topic (what your paragraph will be about); and  
b. containing a controlling idea that limits your topic to a certain aspect to be explored in your paragraph. ["The controlling idea answers the question What does the paragraph explain about the topic?" (FOR2, p. 10)]
2. the attribute of the topic sentence:
As a result, the topic sentence shouldn't be a simple fact or detail; rather, it should contain a specific idea to be developed (explained or argued) in the body part. Within this specific idea, the writer's viewpoint is often indicated.
3. the position of the topic sentence: 
The topic sentence usually appears as the first or second sentence of  an academic paragraph.
References: (simplified)
Effective Academic Writing 2: p. 5   
Focus on Writing 2: p. 10
Writing to Communicate 2: pp. 3-4  

Topic Sentences for Academic Paragraphs

source: eslprof2    2009-09-03

Topic Sentence
source: Simon Williams     2013-05-01

Topic sentence
source: Time4Writing     2010-11-04

The Topic Sentence
source: Jock Mackenzie    2011-12-15

How to write topic sentences
source: Heather Martin    2011-11-10

How to Write a Topic Sentence
source: Taylor Swedberg     2012-09-07