Writing a thesis for a diagnostic essay is similar to writing a thesis for other types of essays. Thesis statements are clear, concise and authoritative sentences that provide the structure, organization and topic of an essay. Teachers give diagnostic essays to assess areas of student strength and weakness so that they can address writing issues. Typically these essays are timed and students are given a prompt or are allowed to choose a prompt from a set of two or three. These types of essays are also used on standardized tests like the SAT to assess a student’s writing abilities.

Reading Prompts

The first step in writing a thesis statement for a diagnostic essay is to read the prompt and to fully understand what the question is asking you. This is the most crucial step because if you read it incorrectly or misinterpret what the question is asking you, your thesis and your essay will be incorrect. It’s better to take a few minutes to adequately understand what the question is asking you so that you don’t work in vain.

Answer the Question

You’d be surprised, but many students trip up on this point. The first thing you should do before you start writing your thesis statement is to write down a simple answer to the question. This actually will be the beginning of the thesis statement. Because of the short time allotted for diagnostic essays, many students jump right into writing without taking time to formulate a thesis that will help them with their essay. The seamstress’ mantra works with essays too: measure twice, cut once. In the case of an essay, plan first or pay later. If you don’t take the time to create a thesis statement for your essay, you could veer off course very easily.

Formulate the Thesis

Once you’ve read the prompt and answered the question, look at your answer and attach three reasons why you think your answer is correct. For example, if a prompt asks you if you think that working harder for things makes you appreciate them more, you answer could be a simple yes. This is not a thesis. However, the statement "Working hard for things makes you appreciate them more because you have to sacrifice, focus and overcome obstacles to get them," is a thesis statement. Simply write a paragraph on each of the reasons and your essay is written. Just make sure that you add an intro and conclusion before emitting a sigh of relief.

Consider Time

Finally, make sure that you allot enough time for each of the steps above. If you are given 20 minutes to complete the essay, then you can break down the time as follows: 2 minutes to read and answer the prompt, 5 minutes for thesis formulation and planning, and thirteen minutes to write the actual essay.