Highlight Preliminary Data in Your Next Application

Funding News Edition: April 05, 2023
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Researcher checks western/moisture blots to know if proteins bind to antibodies.

Data are often only as valuable as the methods you use to generate them. Anything that reflects your research skills and methods can help.

Credit: NIAID

When you’re crafting your grant application, high-quality preliminary data can make all the difference. Here we answer common questions and advise you on how to use preliminary data to your advantage.

Why Should I Include Preliminary Data?

Bolster your application with strong preliminary data to demonstrate two key factors:

  • Approach—your proposed research is promising.
  • Feasibility—your ability to carry it out is credible.

Especially for an R01 application, solid preliminary data can provide added information that will enable reviewers to evaluate your proposed studies favorably. Other grant types may not require preliminary data, but it could still help to include them. More on that below.

How Much Preliminary Data Is Enough?

Though it may be frustrating, there is no easy method to determine exactly how much preliminary data is adequate to justify your particular project. NIAID staff can advise you, but ultimately you must decide how much to include.

We advise you to focus on what reviewers would like to see in your application: enough information to convince them that your proposed project can be accomplished and is likely to have a high impact.

The more paradigm-shifting your hypothesis is, the more you must lay a solid foundation for your proposed projects. Similarly, if your initial findings are surprising, you may want to include more data to convince reviewers that the results are real, replicable, and statistically significant.

You must also assess whether or not your preliminary data are sufficient to convince reviewers that your project has a high likelihood of success. Reviewers use this information to evaluate both the merit of your proposed studies and your skills as a scientist.

When Are Preliminary Data Necessary?

This varies by type of grant. They are required for investigator-initiated R01 applications as well as for several fellowship, cooperative agreement, and program project grants. Check your chosen notice of funding opportunity (NOFO) to confirm.

Preliminary data are not required for the exploratory/developmental grant (R21) or small grant (R03) mechanisms. However, we’ve seen that most R21 applicants include preliminary data, and those who do typically enjoy greater success rates.

If you don’t have any preliminary data for your R21 or R03 application, you should still show reviewers that your project is impactful and that you are likely to accomplish it fully. Make critical assessments of other published research, explaining where and why your additional work is needed. Provide reasoning as to why you are certain you can complete the proposed project.

Certain NOFOs, like requests for applications and program announcements with special receipt, referral, and/or review considerations, vary on whether or not preliminary data are required. You will need to read the individual NOFO for details.

Whether preliminary data are required or not, include any evidence that helps you justify your proposed project.

Should I Include as Much Preliminary Data as Possible?

Keep it focused. Include rigorous preliminary data that directly relate to and justify your Specific Aims. You may also share past research outcomes to establish your expertise with a method or model system.

Don’t include irrelevant information in an effort to impress reviewers with your productivity. We’ve seen applicants fall prey to this temptation, but more data is not necessarily better. Any preliminary data that you do include will be judged and considered during scoring.

For complex or multiproject applications, include research relevant to each component. Be thoughtful in justifying each project with appropriate preliminary data.

What Kind of Data Should I Provide?

Applicants often think of quantitative data as ideal. However, qualitative data provide equally important evidence.

For example, you may use a figure to illustrate your ability to perform a new technique. Include information, flowcharts, and diagrams that support the sensitivity, specificity, and reproducibility of your techniques.

Data are often only as valuable as the methods you use to generate them. Anything that reflects your research skills and methods can help.

As for quantitative data, be sure to include a thoughtful analysis in the text. This helps reviewers assess your ability to interpret your findings, which is especially important for new investigators. Further, you risk reviewers drawing separate conclusions from your own if you neglect to explain why you view the quantitative data as significant.

Must I Personally Generate the Data? 

As the principal investigator (PI), you should rely primarily on research and data that you have generated.

That said, you can include data from collaborators to show that your team is capable of conducting the experiments you propose. If a teammate is meant to fill a gap in your expertise, include supporting evidence that reflects his or her expertise in that field.

You can share data from other investigators to support the significance of your studies. Be sure to include proper citations if you reference outside data in your application.

What if I Don’t Have Enough of My Own Preliminary Data?

Other researchers are likely to have their own preliminary data, so make sure you can compete. You may generate additional data as we suggest in the next question, but we also advise you to consider alternative ways to demonstrate your capabilities as well as the rationale and feasibility of your proposed studies.

As an example, you could support one of your Specific Aims through a literature review. If you take this approach, be sure to provide an original, thoughtful analysis—not just a list of references.

When you reference data, remember that reviewers are not required to read any papers you cite or follow web links you include. Put any critical information that justifies your Specific Aims directly into the application.

Be cautious when you identify unknown information that, once collected, could support your research proposal. That path leads to speculation (bad) and may leave reviewers frustrated that you haven’t already collected that data (also bad).

How Can I Generate Preliminary Data if I Don’t Already Have Funding?

For many researchers, a postdoctoral project provides preliminary evidence for their first independent R01 application.

Without funding, you may still be able to conduct preliminary experiments with others. Network to find other scientists interested in working on the same topic. Read our advice at Build Your Team. For multidisciplinary research, you could apply for a grant with Multiple Principal Investigators.

If you’re an early-stage investigator, focus on collaboration opportunities that allow you to practice and demonstrate the methods and techniques that are critical for your area of research. Find experienced teammates whose strengths complement yours.

Consider the following sources of funding for preliminary research:

Regarding that final point, R03s and R21s are not meant to be stepping-stones for new PIs to reach their first R01. You may find them valuable for generating preliminary data for an R01, but remember that these award types do not convey any special advantages or incentives to early-career researchers.

If you are a new investigator with sufficient data to support the proposed work, we encourage you to apply for an R01 directly instead of an R03 or R21. NIAID typically has a separate R01 payline to support new PIs.

That caveat aside, R03s and R21s are ideal grant types if you wish to explore novel avenues of research. Get more advice at Comparing Popular Research Project Grants—R01, R03, and R21 and Information for New Investigators.

Are There Other NOFOs That Do Not Require Preliminary Data?

Yes. If you are a postdoctoral or newly independent early-stage investigator ready to start an independent research career with highly innovative research projects in mind, consider NIAID’s New Innovators Awards program. The initiative emphasizes innovation and creativity with high impact in NIAID mission areas; preliminary data are not required. Thus, you can pursue novel research ideas rather than being limited solely to topics for which you already have evidence, likely from your postdoctoral experience in another investigator’s lab.

Similarly, the NIH Common Fund’s High-Risk, High-Reward Research Program does not require preliminary data. The four awards in this program support creative scientists with high-impact ideas that may be risky or at a stage too early to fare well in the traditional peer review process—research projects with exceptionally innovative approaches or radically unconventional hypotheses.

Notice of Funding Opportunity

Activity Code

Career Stage

NIH Director's Pioneer Award


Not Limited

NIH Director's New Innovator Award


Early-Stage Investigator

NIH Director's Transformative Research Award


Not Limited

NIH Director’s Early Independence Award


First-Year Postdoc
Final-Year Ph.D.
Clinical Trainee

The next application due dates for the High-Risk, High-Reward Program are in August or September, depending on the specific NOFO through which you apply.

NIAID also participates in the Stephen I. Katz Early-Stage Investigator Research Project Grant (R01, Clinical Trial Not Allowed) NOFO, which explicitly disallows any preliminary data. The initiative’s purpose is to support early-stage investigators who wish to initiate a research project in an area different from their previous research focus or training experience, and therefore have not produced preliminary data.

How Should I Include Preliminary Data in My Application? 

When you apply, you may put your preliminary research data anywhere in the Research Strategy that seems appropriate. Just ensure that your reviewers can clearly distinguish your original research from other evidence you cite. As another option, you could create a separate section with its own header.

Whichever structural approach you choose, make sure it helps you clearly present your past research to show rigorous methodology, insightful and unbiased interpretation, and applicability to your Specific Aims. Learn more at Draft Specific Aims.

Always include adequate explanation and/or a figure legend. If you use a table or figure from a publication, be sure to update the legend or text so that all the information your reviewers need is in your application.

Polish your application so it’s an easy read for reviewers. Keep figures simple and large enough to be clear, with labels on all axes and units. Try placing figures close to where you reference them to save readers from having to flip between pages. Double check your footnotes. 

We advise you to also discuss any limitations of the previous work and how you plan to overcome them. Don’t expect reviewers to give you the benefit of the doubt.

Get examples of how other investigators successfully presented their preliminary research at Sample Applications & More.   

For more advice, talk to a program officer about your application (but don’t send a copy). He or she can advise you on whether your preliminary research seems sufficient to justify your Specific Aims. See When to Contact an NIAID Program Officer.

Contact Us

Email us at deaweb@niaid.nih.gov for help navigating NIAID’s grant and contract policies and procedures.

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