3b. Evaluate Sources Broadly

3b. Evaluate Sources Broadly#

Introduction#

When you are presented with a source, before you start reading and using it in your project, you need to make sure if it is worth your time. You do so by checking two aspects of the source: its relevance and its reliability. Once you have included a source in your project, the evaluation doesn’t stop: critical reading is necessary to further check the source. This will be further discussed in the chapter on Processing sources. This part focuses on evaluating sources in a more broad manner.

Step 1

Evaluate Relevance
Evaluate if a source connects to your project

Step 2

Evaluate Reliability
Evaluate if a source is reliable

Step 3

CRAAP Test
Use a framework to evaluate sources

Step 1: Evaluate Relevance#

Finding information is easy. However, deciding which information to select and use in your own project is more difficult. To evaluate your search results you need to know if the information you have found is really relevant and reliable. Bad search results can lead you, for example, to make the wrong research conclusions or to reinvent the wheel. The relevance of information of your search results is determined by the project you are working on. A book or article can be scientifically sound and well-written, but if its subject is not what you are looking for, it is of no use to you.

When deciding if a source is relevant, the key questions are: Does it help answer my research question? Does it contribute to my work? If so, in what ways? (Southern New Hampshire University, 2025). A source can be scientifically sound and well-written, but if it doesn’t address at least some part of your research question, it may not be useful for your project.

Here are some points to consider:

  • Topic match: Does the source address your actual topic, including any specific aspects you are exploring (such as geographic areas, populations, or age groups)?

  • Purpose of use: Can you use this source in your project? How does it apply to your work and how exactly will you use the source? For example, some sources are helpful for background context, others for definitions, data, graphics, or as inspiration for your methodology.

  • Level and depth: A very basic overview might not add much if you already know the fundamentals, while an overly technical article could be difficult to understand or apply. The best sources are at a level where you can understand them and actually use the information in your work.

  • Scope and focus: Does the source cover the right breadth of your topic? Some sources may be too general and only touch on your overall subject. Others may be too narrow and focus on just a specific detail, without considering the other aspects that matter for your research.

Tip

A source doesn’t need to cover every single part of your research question to be relevant. Often, a source will only match part of your question. For example, it might focus on the right topic but only look at a specific country or a particular age group. That doesn’t necessarily make it useless. By combining several sources that each cover different aspects, you can often put the pieces together and create a complete answer to your research question. However, in some cases you do need sources that directly cover all elements of your research question. For instance, if your question is about legislation in a specific country, information about laws from elsewhere won’t help much, since legislation is usually country-specific.

Step 2: Evaluate Reliability#

Reliability is a characteristic of the information itself. Information found online ranges from online scientific journal articles to personal blogs, and from open access research data to sponsored reviews. The information may be completely reliable or very unreliable. It is not always obvious to which category it belongs, so you need to look at certain criteria to decide whether the information is reliable before you use it. Can you trust it? Is it based on scientific research or is it someone’s personal opinion? Decide if a search result from a certain information type is reliable by examining the:

  • background information on the author(s).

  • audience for which the information is intended.

  • purpose for which the information was created.

Tip

Tip: If you are not sure about the reliability of your source, try to find additional information to confirm the information you are not sure about, or ask your supervisor. If, after that, you are still not sure about the reliability or scientific quality of the information you have found, it is best that you mention this in your work, or avoid using that source altogether!

Step 3: Use the CRAAP test for evaluating#

There are multiple frameworks for checking reliability of a source.

A widely used tool for evaluating reliability is the CRAAP test (Blakeslee, 2004), which looks at five key elements:

  • Currency: Is the information up to date? Does the date of publication matter for your topic? (For example, medical research quickly becomes outdated, but historical sources may not.)

  • Relevance: Does the information directly address your research question or project? Is it written at an appropriate academic or technical level?

  • Authority: Who is the author or organisation behind the source? Do they have the expertise or credentials to write about the topic?

  • Accuracy: Is the content supported by evidence? Are references or data provided? Can you verify the claims in other reliable sources?

  • Purpose: Why was the information created? To inform, teach, persuade, entertain, or sell something? Watch out for hidden agendas or commercial interests.

When you apply these questions, remember that not all sources need to score perfectly on every criterion. For example, a company website may not be completely objective, but it can still be useful if you need to know how that company presents its technology. The important part is to be critical and deliberate about how you use different kinds of information.

Example CRAAP test

Imagine you are writing a report on the environmental impact of lithium-ion batteries used in electric vehicles. You find the following sources:

Category

Source 1

Source 2

Source

The Future of Electric Cars: What the Next Decade Holds (blog post). Retrieved from https://www.evisionevs.co.uk/2025/09/02/the-future-of-electric-cars-what-the-next-decade-holds/

Pollution from electric-battery production mitigated by longer car use (news item). Retrieved from https://cen.acs.org/environment/climate-change/pollution-mitigated-electric-battery-production/103/web/2025/10

Currency

The post is from September 2025, so the information is recent.

This news items was published in October 2025, therefore the information is up-to-date

Relevance

It talks about electric cars in general, not specifically the environmental impact of batteries. It might not address your research question directly.

It specifically discusses pollution from the production of electric car batteries, and therefore it is highly relevant.

Authority

Author is “David”, but there is no further information about him and no way to evaluate his background. The blog post is published in the website of a company that rents and sells electric cars.

It is written by Helen Albert, who is a freelance science journalist specialising in healthcare, life sciences, bioanthropology, biotech and innovation. Retrieved from https://www.helen-albert.com/ The news item is published in c&en, which is backed by the American Chemical Society.

Accuracy

It does not provide references or data to support its claims. Any predictions about the future of electric cars are based on speculation.

It recaps and comments on a specific paper by P. Sadavarte, D. Shindell and D. Loughlin, which is directly cited. It also quotes V. Thomas, who is an expert in the field.

Purpose

The goal of the post is to persuade people to buy electric cars. It is promotional, not neutral or academic.

The goal of the news item is to inform researchers and the public about new findings of scientific research.

Conclusion

This information is superficial and not reliable enough for an academic paper. You should verify the given information with another source.

This information is quite reliable, but superficial. For use in an academic paper, try to find the publications written by the actual researchers themselves.

When evaluating scholarly sources, you can also use the CRAAP test. However, to do a full evaluation of an academic source, you also need to read the source carefully. Conclusions of studies can depend on small details in the study setup, and you may not see this when glancing at the titles and abstracts or an AI-generated summary. Judging Accuracy (Is the argument presented consistently? Do the results make sense?) may therefore come after you have considered the other aspects, and have included a source in your reading list. The steps for evaluating and processing therefore overlap and go hand in hand for scholarly sources.

Practice with Research Scenarios#

"Test 3a: Evaluating Sources" by TU Delft Library Education Support is licensed under CC-BY

References#