Thesis

A thesis statement in an essay is a sentence that explicitly identifies the purpose of the paper or previews its main ideas.

The thesis statement is that sentence or two in your text that contains the focus of your essay and tells your reader what the essay is going to be about.

A strong thesis statement takes some sort of stand, justifies discussion, and expresses one main idea.

When your reading summary is targeted at Thesis statements
1) summarize the reading

If you don't know how to write a basic summary, check out these two online resources: http://www.smc.edu/AcademicPrograms/English/Reading-Center/Pages/Writing-a-Summary.asp & http://writing.colostate.edu/guides/teaching/rst/pop5h.cfm

2) Identify the thesis of the assigned chapter(s)

An example:

HoI Chapter 1 Summary & Thesis

Summary:
In a time where the ability to respond to substantial nuclear attack in kind was an absolute necessity, the United States military found its communication lines unable to do so. Were a line to be broken from the sender to the receiver, no communication could be made, rendering that receiving branch useless and the sending centre helpless. The United States’s many methods of communication with its military could be quickly and easily disrupted. It was necessary, then, to rethink how the military communicated with its many branches.
 
RAND researcher Paul Baran’s proposal for “nuclear-proof communications” was the concept of a digital network of nodes, as opposed to the analog network of a centre and its many branches that the United States currently employed. This digital network would break up its message into many packets which would then be sent to a node, who was then responsible for passing along the packet to whatever node would get it to its destination quickest. This way, packets would not be bottlenecked were a node to be subject to nuclear attack (or otherwise unavailable); this also meant cheaper, more unreliable technology could be used, as a failure of equipment merely temporarily rerouted communications to the next quickest line.
 
This concept of digital packet-based communications was immediately and vehemently rejected by then-communications monopoly AT&T, who refused to believe that cutting messages into packets would result in transmissions as clean as the current analog based transmissions. The project was then given an option: pass the project along to the DCA, who likely would botch the job due to lack of understanding of digital technologies and a lack of enthusiasm, or shelf the project for a later date. Baran chose the latter.
 
The demand for fresh ideas and technological developments, however, was just beginning. The establishment that would one day become the National Science Foundation, critical to the future development of the Internet, was brought about by Science: the endless frontier. Shortly after was the development of Project RAND, an oddly independent and freeform research outfit, where Baran would unshelve his digital packet-switching communications concept, although this time, the concept reached beyond the realm of military usage and into the realm of public utility.
 
Thesis:
The Internet was born out of a cold-war necessity for reliable, de-centralized, communications but grew beyond its military use into a public utility.