A good thesis on charter schools might relate to their impact on the life chances of under-privileged children. Supporters of charter schools argue that they greatly improve the life chances of children otherwise failed by the public school system. Opponents are equally adamant that they do no such thing; merely removing a small number of under-privileged pupils from public schools and sending them to charter schools does nothing to help those left behind.

What makes this a good thesis statement is that the vexed question of whether charter schools improve the life chances of under-privileged children is arguably the main bone of contention between the policy's supporters and detractors. This means that you should be able to find a lot of good arguments on both sides of the debate that you can use in support of your thesis. Whichever side you choose to support, it's important to make sure that you advance rational, well-thought-out arguments to back up your case, instead of merely giving vent to your emotions.

Personally, I think it is best to select a thesis not necessarily based on personal belief but rather based on which position you could best support with evidence.

In this case, it would be a wise choice to argue that charter schools have a negative impact on public education.

A claim is a specific type of argumentative thesis that you should use. It includes a position and reasons to explain your position. However, I think it’s best to avoid a “laundry list” approach while trying to incorporate multiple reasons.

Try using the following sentence stem:

Although ____________________, charter schools are bad for public education because they _____________, ____________, and ______________.

In the first blank, you should include an argument that your opposition would use in support of charter schools. In the last three blanks, you should include action verbs followed by something charter schools “do.”

Example: because they “exclude diverse groups,”

I want you to research some other reasons why charter schools are bad and find a way to write those in parallel structure with the example provided.

Are you arguing for or against charter schools?  Charter schools are a very broad category.  Some are great, and some are terrible.  You can use examples of specific charter schools that are doing well.  If you are arguing against them, I would focus on the fact that there are not many similarities.

If you want to argue that charter schools are not good, you might have a thesis statement like this: 

Charter schools have a negative effect on public education because they siphon off funding from regular public schools, because they are in many ways beyond the control of the public school district, and because the results they achieve in learning are often no better, and sometimes worse, than the results achieved in regular public schools.

So, are you asking about a good thesis for an argumentative essay about charter schools?  If so, you have to base this largely on what you believe.  If you believe charter schools are good, a good thesis might be something like "Charter schools have the potential to improve the school system by forcing the regular public schools to compete for students."