Complete Guide on How to Write a Diagnostic Essay

A lot of students enter their college classroom and are surprised that they need to write a diagnostic essay right away They ask, “what is a diagnostic essay?” as they are handed the prompt. Don’t be one of these students—know the diagnostic essay definition and structure, as well as the vital tips for writing a good diagnostic paper.

What is a Diagnostic Essay?

By definition, a diagnostic essay is a kind of test that colleges and universities use to gauge their students’ writing capabilities and knowledge level by In most cases, students are given a prompt and are asked to write an essay within an hour or less. This is usually included as part of the admission test or assigned on the first day of class by professors.

Writing diagnostic papers does not require research, as it relies mostly on the students’ general knowledge. Neither does it require citations since students do not have the time to research. Nevertheless, students are expected to showcase their writing style as well as their time management skills.

The good news is that these papers are not graded unless they are part of the college admission test. However, they are still quite challenging as professors use prompts that require analytical thinking. Furthermore, your work will tell your professor whether you are ready for their course or if you will need additional support. In any case, it would be great to impress your professor with your first task by writing a good diagnostic paper.

Diagnostic Essay Structure and Format

Diagnostic writing needs to be concise and logical. Thus, the most efficient way to write a diagnostic essay or any essay for that matter is to follow the standard essay structure: introduction, main body, conclusion. Here’s what each section should contain:


Tell the reader what you are writing about with an interesting hook or first sentence. The common practice is to rephrase the prompt to introduce the assigned topic, then tell the reader your thesis statement about the topic and your three main points or arguments.

Main Body

The main body consists of three paragraphs, with one paragraph tackling one argument each. For each paragraph, state your main point, then provide supporting details. Since you do not have access to research, you may use personal experience or facts you know.


This is the last paragraph of your paper, so this is where you tie up your main points and relate them to your thesis statement. You may rephrase your thesis statement to reinforce your point but do not introduce new topics or arguments here.

If you follow this structure for your diagnostic essay, you are already ahead of the game. However, to write a truly good diagnostic paper, follow the writing tips in the next section.

How to Write a Diagnostic Essay: Tips and Tricks

Since students only have one hour to complete a diagnostic essay,  they are expected to apply their analytical thinking and writing skills efficiently. The time pressure often becomes overwhelming for students, but you can manage that by preparing how to write a diagnostic essay.

1. Choose Your Topic Wisely

Most of the time, you will have a few topics to choose from. Consider each one carefully and assess how much you know about the topic. Choose the topic that you are most familiar with and you’re sure you have sufficient knowledge and experience to write about. If you’re not sure, it’s best to prepare a prompt in case you are asked to think of your own diagnostic essay topic.

2. Write a Strong Thesis Statement

Your thesis statement is the core of your essay. It communicates your main idea or stance on the topic. So, construct a strong thesis statement before starting with your essay. Your thesis statement should answer or address the question or prompt then list down your three main arguments.

3. Treat the Introduction as Your Outline

Your introduction, naturally, should introduce the topic of your paper as well as your thesis statement. It should also outline your main points or arguments. Since you likely don’t have time or space to plan out an outline, refer to your introduction as you write the paper to make sure you stay on track.

4. Write an Attention-Grabbing Hook

Your professor has no choice but to read your paper, but you can still make it interesting for them. Open your essay with an interesting hook that both informs the reader of your topic as well as excites them.

5. Use a Topic Sentence for Each Paragraph

In addition to using the appropriate transitional phrase to start your paragraphs, you should make sure that you write a topic sentence as well. A topic sentence introduces the main idea of the succeeding paragraph so the readers know what to expect. This also helps you stay within the topic, therefore improving your paper’s organization.

6. Proofread Your Essay

Even though this task has a time limit, try not to skip the proofreading step. In your haste, you might choose the wrong words or forget to write some prepositions, and so on. Going through your essay at least once will significantly improve its quality, and the reader (aka your professor) will be able to tell if you proofread or not.

Diagnostic writing requires efficiency, meaning you need to be fast without compromising quality. Practice writing a diagnostic paper while following these steps to help you prepare for the actual diagnostic test in your college.

Best Diagnostic Essay Topic Ideas

While schools and professors often select one or a set of prompts, some allow students to select topics on their own. This could further overwhelm a student, but not if you are prepared for this possibility. Choose and practice with these diagnostic essay topics that will showcase your knowledge and writing prowess.


  • Why is the media important in our society?
  • What is the significance of cultural identity in individuals?
  • Does stereotyping have a positive impact?
  • Why are people fascinated by celebrities’ personal lives?
  • Why do people listen to music?


  • What is the importance of a college education?
  • Why did you choose to attend this school?
  • Is standardized testing obsolete?
  • How can we bridge the educational gap between the rich and poor?
  • How can classrooms be more inclusive?

Politics and Society

  • Does the US have a responsibility to maintain peace and order in other countries?
  • What does “unbiased reporting” really mean?
  • Will gun control fix America’s violence problem? Why or why not?
  • Drug addiction is a mental health problem. Agree or disagree?
  • Do social media sites (i.e., Facebook, Instagram, YouTube, TikTok) have a responsibility to filter hateful content (e.g., racist, homophobic, transphobic)?


  • Has the Affordable Care Act (Obamacare) improved US healthcare? How?
  • How should the government handle the anti-vaccine movement?
  • Are healthcare workers underpaid and overworked?
  • The importance of political correctness in the healthcare setting.
  • How can we fight the problem of obesity in the US?


  • Is outsourcing a good idea for businesses?
  • What are the main manifestations of gender bias in the workplace?
  • What are the pros and cons of inclusivity and diversity in the workplace?
  • Should businesses have social media accounts?
  • What is the role of businesses in combating climate change?

Ace Your Diagnostic Essay

Diagnostic essays tell your college or professor how well-versed you are in relevant issues and how well you can write essays. Although these are not graded, you should still prepare. Practice your writing and get expert advice as early as now to impress your professors.


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