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Evaluate information

Source criticism is a central part of information management. You need to select appropriate sources and evaluate their credibility. On this page you will learn about questions you can use to do this, and get more information about some common types of publications

Workshops about evaluating information

When you have found sources that seem relevant, you also need to evaluate them and assess their credibility. If you have found many sources, an initial evaluation is necessary to choose which ones you want to investigate more closely. 

You can ask a number of questions about the sources in order to evaluate them. Some of the questions are easier to answer than others. It is usually a good strategy to start with them for the first evaluation. You then use the more complex questions after you have done an initial screening. Questions that are easy to check include who created the information, where it was published and when it was published. More complex questions involve evaluating the methods used in the source and putting the content of the source in relation to other sources. 

The questions below can be used for all types of sources. Scientific sources will always fulfill some of the criteria. They have been reviewed before publication and meet a basic level of reliability. But you still need to critically evaluate scientific sources. To be able to answer some of the questions, you need subject knowledge and knowledge of scientific methodology. This means that you can make a more in-depth evaluation the better you know the subject and master scientific methodology. When you're a new student, it might be enough to be able to identify that it is a scientific source, and check out the simpler of the criteria. 

Questions to ask about the source

Light bulbs sketched on whiteboard and the text critical thinking
Image by Lisa Blue from Getty Images Signature. Canva License.

To carry out a critical review of sources, you can use the following questions.


  • Who created the information?
  • Is there a named author? Is the person an authority in their field? What other type of information has the person published? 
  • Is there no named author? In such cases, did an organization, national agency or company publish the information? Can you find information about the responsible agency? 

Try to find out who produced the information. It can be a named person or an institution. Also try to assess whether the person or institution have good knowledge of the subject. If you can neither find a person nor institution responsible for the source, it is difficult to judge its reliability. In such cases it is better to choose other sources.


  • Where is the information published?
  • Has the information been reviewed before or after publication?

Check where the information was published . Can you find information about the publication process? Was the source reviewed at some stage, and, if so, how extensive was this review? A rule of thumb is that both books and scientific articles are usually reviewed before publication, by an editor or, in the case of scientific articles, in the so-called peer review process, where other subject experts decide whether the article should be published and suggest improvements.

It is also a good idea to try to find the published version of the source you want to use. Other versions may be incomplete or incorrect. If the source has been revised, the changes made in the published version may not be included in the other versions.  

So-called preprints are scientific articles that have not yet undergone peer review. Check if you have access to the published article and use this version in the first hand if you can. Sometimes copies of sources are posted on various websites. If you can find and access the version from the publisher, that is preferred. 


  • When was the information published? Is it still current?
  • Has something happened in the research area that affects or contradicts the source? 

The sources you use should be current, that is: not outdated. Note that older sources may be relevant if the information presented is still valid. It is not possible to set a general time limit for how recent sources must be in order to be current. It depends on the subject area and specific question. In some areas, development is rapid, while other subjects are more stable.


  • What is the purpose of the source? Has it been published to inform, persuade or sell something? 
  • Who is the target group for the source? 
  • Does it appear to be objective or does it represent certain interests and is biased? 
  • Could there be a hidden agenda, meaning there is an unspoken purpose? 

Make an assessment of the purpose of the source. Scientific sources have the purpose of informing about research results, while debate articles are written to convince and advertising has the purpose of selling. The purpose of other types of sources may be more difficult to assess and there may also be unstated purposes and a risk of bias, for example through the authors' connections to companies, political parties or interest organisations. Primarily choose objective sources with the purpose to inform. You might find useful information in sources where there is a risk of bias too, but it is good to be aware of the risk.


  • What is the source of information in the text? Did the authors perform a study of their own or read other sources? 
  • Is the method described? 
  • Are there references or a bibliography? 
  • Is it a primary or secondary source? 

In scientific articles, the method is clearly described and there are references to the information taken from other sources. Other types of sources sometimes describe how the information was compiled and there can be references or a bibliography. 

If there is no information on how the information in the text was produced and no reference to other sources, it becomes more difficult to assess the credibility of the source. 

Primary and secondary sources

A primary source is the source where specific information is published for the first time. In science, a primary source is the source where results from a research study are published for the first time. If this source is a scientific article, it is called an original article. 

The term primary source is also used for other types of sources . It can for exampel refer to the news article that first reported on an event, or the report where statistics were made available for the first time. Secondary sources are sources where previously published information is reproduced or summarized. Examles include review articles, course books and articles in Wikipedia and other encyclopedias. 

In science, it is an important principle to primarily refer to primary sources. That way, the right person gets credit for the results. When information from one source is reproduced in another source, there is a risk that it will be distorted or misinterpreted. By going back to the primary source, the risk of misinterpretation is reduced. 

But depending on the type of information, secondary sources might be useful as well. For basic facts or an overview of the state of research, secondary sources may be appropriate. It can be useful to first read up on the topic using secondary sources. 


  • Does the facts in the source appear to be correct?  
  • Do they agree with the knowledge you already have?  
  • Do they agree with other independent sources? 

Put the source in relation to other sources and the knowledge you already have. Is the source consistent with other information, or does it differ? If a source deviates completely from your previous knowledge and other sources, there is reason to review it more carefully. At the same time, you should be on your guard against what is called confirmation bias. Confirmation bias means that we prefer to have our world view confirmed and have more difficulty accepting information that makes us need to reevaluate our knowledge. 

Often when information in different sources contradicts each other, it is not as simple as some sources being wrong and others correct. The situation is generally more complex.. The conflicting sources may write about the subject from different perspectives, have studied different groups or variants, or perhaps they have applied different methods. When you find conflicting sources, part of critical source evaluation is to weigh them together and try to understand the reasons for the differences. It is often good to include the contraiciting sources in the text and explain that different sources have come to different results. 

Scientific information

As a student, you are part of academia which means that you will be involved in scientific communication, both as a reader and a writer. To be able to produce scientific information yourself, you need to learn to independently search for, critically evaluate and use information of various kinds. 

A general characteristic of scientific information is that it is written by researchers who present new results. The primary target group is researchers in the same research field. Theoretical starting points, methodology and results are often presented according to a certain structure in a neutral way and with terminology that is typical for the specific research area. Scientific texts also have references to sources to mark the boundary between previous research or other types of sources and the researcher's own findings.