To apply critical thinking when you read, try doing the following:
1) Read the text carefully, asking questions.
2) Check the evidence used in the text, especially if the source is not peer-reviewed.
3) Compare with other sources dealing with the same topic.
4) Evaluate and draw your own conclusions.
When you read critically you need to question and engage with the text. This takes time and requires deep reading. (You may firstly undertake an initial skimming/scanning of the text to check that it is useful before launching into critical reading, see Effective Reading).
In order to evaluate the source you are reading, you can ask the following questions:
What is the evidence used by the source you are using? Facts, data, primary sources, other secondary sources?
Check if the evidence is:
Remember that even quantitative evidence can be misleading. Statistics can be abused, presenting a partial perspective to bolster weak arguments.
This notion underlies the popular quip (attributed by Mark Twain to Benjamin Disraeli): "There are three kinds of lies: lies, damned lies, and statistics."
Literature on the same topic
In order to better evaluate a piece of work, you need to compare it with other sources dealing with the same topic(s). What do other authors say about the topic(s) discussed in the source you just read? Expose yourself to different authors and perspectives.
The more you read, the more likely you are to reach a sound judgment on the topic you are studying!
Literature commenting on the source you are reading
You can also check if there is some literature directly commenting on the text you read. Use Google Scholar for forward citation tracking (finding newest sources that cite a particular source) to help you find what other literature comments on a certain source. See the guide on using Google Scholar.
Once you have critically read the text, think of what conclusions you can draw from the points it makes.
When you read for your assignment, keep in mind your purpose, that is, to retrieve information that you will analyse and discuss in your own writing.
If something is relevant, make sure you take notes and record the reference. The reading will be part of your analysis of the topic you are writing about, and may be reported in your final text, perhaps as a quote, paraphrase, summary or synthesis.
If something is irrelevant, don't dwell on it! See also our guide on effective reading.
In the following video Doug Specht, Senior Lecturer at the Westminster School of Media and Communication, presents steps for critical reading:
You can become a better critical thinker by keeping these points in mind: