How to determine the truth is the essence of critical thinking. In our age of information overflow, it is very difficult to determine what is believable and what is not. This is especially critical for correct evaluation of scientific and engineering sources. The worst thing you could say is that something is true because your teacher said so; even worse if Google said so. Both are extremely unreliable as potential measures of truth.
So, how do we know if something is true? Formally, a given claim is true if it allows correct prediction of the outcome or future event based on logic. Why should you care about truth when most people don’t? Well, the truth is based on reality, and if you are engineer or scientist who is not producing a design/research based on reality, it could be dangerous. Delusions and misconceptions are common among people, but they are difficult to correct. It is better to have less of them from the beginning.
The only known pathway to truth is research and replicable experiments which provide sufficient evidence for something being real. Unverifiable (unfalsifiable) claims and experiments that cannot be replicated cannot be used to form opinions about truth. Unfortunately, you cannot do research and experiments on every single claim or question in science and engineering. So, you have to create your own opinions based on the data presented to you and you need to decide if it is reliable.
Here is a short guide on how reliable different sources of information are:
- Most reliable (peer-reviewed by best experts in the field)
Scientific articles published in well-respected journals with rigorous peer-review process are most reliable. Those journals are generally published by known publishers such as Springer, Elsevier, IEEE, etc. The fastest free method for evaluating the quality of a journal is to use the following databases: Scientific Journal Ranking or Scopus Sources. If the journal is not in the database, it is not reliable. Higher SJR index means higher reliability and better journal (well, not always, but good enough for the initial impression). Some top-level conferences are also a good source of reliable information. These kinds of sources are called primary sources because they are written by the original authors of the research.
2. Moderately reliable (peer-reviewed by experts and non-experts)
In this category, we have review and survey articles, encyclopedias, textbooks (secondary sources) where the authors describe their understanding/interpretation of somebody else’s research. As expected, some interpretations are correct and some are not. Those sources are generally good for a fast introduction into a subject of study. Always use primary sources for more in-depth understanding.
3. Somewhat reliable (peer-reviewed by non-experts)
Most journal and conference publications from less reputable publishers are in that category. Those journals and conferences cannot attract top level most knowledgeable experts to review their submissions. You should be very suspicious and skeptical about the presented claims.
4. Not reliable at all (not peer-reviewed)
Internet blogs (including this one), web pages (Google search), movies or YouTube videos, somebody said something (your teacher, friend, manager, etc.), scientist’s opinions not in the area of their expertise, technical reports are all unreliable.
Look, nothing is 100% reliable and you should never have 100% confidence about anything, but having 80% reliability is much better than 0%. You could base your confidence level on the academic peer-review process. More rigorous and scrupulous this process is – higher the probability that the reviewed claims are true, or at least they give the best explanation available so far.
Make a habit of checking the facts and scientific evidence before jumping to conclusions.