Here's the definition:
Critical thinking is "an investigation whose purpose is to explore a situation, phenomenon, question, or problem to arrive at a hypothesis or conclusion about it that integrates all available information and that can be convincingly justified."
This definition was taken from a book by Joanne Gainen Kurfiss titled Critical Thinking: Theory, Research, Practice and Possibilities (2).
This can be applied to something you read in a book, or a magazine article. It can be applied to something you hear in a lecture or in a commercial on television or even in an argument with friends. In short, it can be applied to any proposition that comes before you.
Note that a crucial part of the definition is that the hypothesis or explanation developed "integrates all available information." This means that your explanation must not overlook important information. That is an important TEST of how successful your explanation is.
"Opinions" represent a special problem. According to the Kurfiss, one of the most important things that students can learn is that opinions are not necessarily "knowledge." Rather they are "knowledge claims that have stronger or weaker grounds and that their merits can be discussed" (emphasis added).
For me, this is the most important lesson that can be learned about thinking.
What that really means is that opinions need to be challenged more than they are. We simply should not accept things uncritically.
This is a very important point. How many times have you heard your instructor ask someone in class to respond to something someone else has said and the reply is something like this: "Well, she has a right to her opinion"? Or: "Everybody has the right to their opinion."
Sadly, that happens all too often. What we should be saying more often is something like this: "How do you justify your position?" Or: "What is the evidence you have for saying that?" Or: "Where do you find support for that in the text?"
Kurfiss quotes other researchers to show that there "is increasingly compelling evidence of serious deficiencies in the ability to reason among college students and the limited influence of college education on critical thinking skills. Depth of argument on controversial topics is minimal and increases only marginally as a result of college instruction..." (1). To me as an educator, that's shocking.
She goes on to say that research shows that "[c]ollege students make judgments on the basis of unexamined personal preferences, even after four years of college" (1).
That's the bad news. The good news is that critical thinking skills can be learned -- even if they're not being taught. (And according to Kurfiss, educators bear much of the responsibility for how students think because we have not emphasized critical thinking skills in the past.)
What all this means for college students is that they need to focus on learning skills that will enhance their ability to think critically.
Numerous activities have been identified with critical thinking, are evidence of critical thinking. The following list of of activities has been compiled from a variety of sources. These sources suggest students need to be able to:
Here's some more interesting stuff on critical thinking: