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RMIT University Library - Learning Lab

Critical reading



Critical reading involves developing a deep understanding of the content of a text as well as an analysis of the author’s claims, evidence, arguments and conclusions.

It involves examining the text to identify the main ideas and perspectives, but it also includes interpreting and evaluating the strength of the argument or conclusions. You can read a text on at least four different levels.

Comprehension: read to find out what the text says. Ask yourself: what are the main ideas of the text?

Analysis: read to see what the text does. Ask yourself: how is the information used, how is it structured, how is it trying to persuade me?

Interpretation: read to find out what the text means in a broader context. Ask yourself: what is the deeper meaning of the text? What are its implications?

Evaluation: judge the text’s strengths and weaknesses. Judge whether the text is important in terms of its contribution to the field.


Read the passage below

The discovery of antibiotics was contributed to by two scientists, Alexander Fleming and Howard Florey. Prior to 1942 patients in hospitals were dying from sepsis after amputations or from other invasive procedures. Women died in large numbers from infections caused by childbirth, and there was no great effort being made to find some form of antibacterial agent. In 1930, the microbiologist Fleming, who was studying micro-organisms and their growth patterns, wrote up his observations of the effect of bacteria on an organism for a small medical journal in London commenting that this might be worth further investigation; however, it wasn't followed up for 10 years. During the Second World War, men injured in battle were dying from sepsis in wounds. An Australian, Florey, who was working at Oxford University, was given the job as part of a PhD to try and find some bacterial agent. He came across the article written by Fleming and decided to follow it up. He managed to isolate enough penicillin from the penicillium fungus to treat one patient. America put money into this research and Florey and his assistant started to produce penicillin on a mass scale. There was enough produced in 1942 and 1943 to treat most of the allied soldiers, sailors and airmen that were being injured. 

This text was devised for teaching purposes only. The content is regarded as general knowledge


Apply the four levels of critical thinking 

The passage about the contributions of Fleming and Florey can be critically analysed by considering the following points.

  1. Florey, building on the work of Fleming, managed to isolate penicillin during the Second World War. (Comprehension: presents the same information as the original. It restates the information.)
  2. The passage compares the contributions made by two scientists to the development of a life-saving anti-bacterial agent. (Analysis: discusses the way the material is presented and structured, showing deeper insight.)
  3. The high numbers of soldiers dying of wound infection in the Second World War was the possible catalyst for the invention of penicillin. (Interpretation: attempts to find a deeper meaning, interpreting the overall meaning of the passage.)
  4. The article provides a good basic summary of the early history of penicillin, but it ignores the work done by Moyer which allowed the drug to be produced in large quantities. (Evaluation: judges the text in terms of its strengths and weaknesses.)