Skills Every Student Needs: Defending Ideas with Evidence

Mon, 05/19/2014 - 10:00 -- Anonymous (not verified)

This is the second post in our series on important cross-disciplinary skills that all students need.

If there’s one thing people seem to know how to do, it’s state an opinion. They may even be quite good at it. However, being opinionated does not mean that you are successful at persuading people to adopt, or even hear, your point of view. To be effective at persuasion – the ability to influence someone’s actions, attitude, or beliefs – you need to be convincing, and being convincing requires more than just stating your idea. If a friend tries to tell you that the latest big dollar action movie is the “best ever” and you should “immediately go see it”, you would probably want some more information before you rush out to the theatre, such as: what makes it so good? or why is it better than anything else I’ve seen? What if you don’t really like action movies or the people starring in it? What could your friend say to convince you this movie is worth your time?

The answer to these—and most questions relating to what makes something persuasive—is evidence. To convince someone to listen to, and possibly accept, your idea, you need outside evidence that supports your point. Effective evidence can change minds. If strong enough, evidence can even influence disagreeing minds, taking naysayers from the belief that “No way that’s possible!” to “I guess that could be true for this situation”.  If you are able to get an opponent to see the logic in your ideas, then you have successfully backed up your opinion with something solid and convincing.

The story of the three little pigs is a great metaphor for this idea. When the big bad wolf comes knocking, would you rather be in a house of straw or a house of bricks?

The more evidence you have, the stronger your foundation.  

However, is all evidence created equal? I bet you can guess that the answer is no. Think of commercials. If someone with sparkly teeth tells you that a certain brand of toothpaste will give you a bright smile, are you going to believe this claim? What about if he or she adds, “4 out of 5 dentists say this toothpaste is better for your teeth”? Which proof are you more likely to believe?

Categories of Evidence

Certain kinds of evidence are more convincing than others, making the three main types of evidence—Facts and Statistics, Expert Opinion, and Anecdotal Evidence—varied in strength.

  • Facts and Statistics tend to be the most reliable because they can be proven and are often difficult to argue against. As an example, think about statistics, which are usually achieved through logical and systematic procedures, making them quite reliable. The results are easy to see and understand. However, it is important to remember that statistics taken out of context can be misused, so you should always verify the source of a piece of evidence.
  • Expert Opinion can also be reliable because it is based on the testimony of someone who is credible on the subject in question. People usually like to hear what authority figures have to say and are willing to believe their experience. However, for the information to be truly effective, you need to know the expert’ credentials (how much experience they actually have) as well as any biases they might have (what they stand to gain from their testimony).
  • The last form of evidence is Anecdotal, which is a real life account of a person or event. This evidence supports that something happened because someone witnessed and can attest to it. However, anecdotal evidence is as reliable as the person giving the testimony. Think about five people witnessing a car accident. Do you think they will each describe it the same way? Depending on how close and unobstructed a witness’s view, how distracted he or she was, or how trustworthy the person’s state of mind, some testimony will more accurately represent “the truth”. Even people in similar positions and with similar qualifications might report different accounts. Therefore, the more eyes that can document something, and the more reliable those eyes are, the more you can trust the resulting information. Still, Anecdotal Evidence is important. A criminal could go to jail based on an eyewitness who can put him or her at the scene of the crime.

How Can College Readiness Assignments Help?

Because CRAs are meant to help prepare students for the habits of thinking that are necessary to be successful in both college and career, they address and are aligned with the College and Career Readiness Standards (CCRS), which were developed in coordination with the Texas Higher Education Coordinating Board (THECB) and the Texas Education Agency (TEA). If you consult the CCRS, you’ll find that in the standards for each of the four core subject areas, as well as in the Cross-Disciplinary standards, students are required to recognize and use evidence in their work. If you are looking for ways to develop and sustain students’ ability to incorporate evidence into their work, below are a few examples of CRAs (and the corresponding CCRS) that specifically address and assess this skill.


The Cross-disciplinary CRAs are appropriate for use in any course and are adaptable to the content you are currently using with your students.  Some of the cross-disciplinary standards that address evidence are:

Ø  I.B.2. Construct well-reasoned arguments to explain phenomena, validate conjectures, or support positions.

Ø  I.B.3. Gather evidence to support arguments, findings, or lines of reasoning.

In “Exploring a College Textbook,” students analyze a college-level textbook’s organization and its methods of presenting information; students also discuss strategies a reader might use to comprehend and remember material from this text.

English/Language Arts:

In ELA, students must be able to follow an author’s arguments and decide whether or not the author has convinced them of a particular point of view.  The ELA standard for working with evidence is:

Ø  II.A.5.  Analyze the presentation of information and the strength and quality of evidence sued by the author, and judge the coherence and logic of the presentation and the credibility of an argument.

Reader’s Analysis: Author, Purpose, Audience, and Meaning” is a CRA that really challenges students’ skills in not only finding evidence but deciding into which category the evidence falls. In this assignment, students read, study, research, and discuss Martin Luther King, Jr.’s "Letter from A Birmingham Jail," in which he addresses criticisms of his actions. His writing attempts to persuade his audience that his stance and actions are correct. Instructors can choose to substitute any persuasive text for this assignment so that students can practice looking for evidence in several contexts.


While we often think that math and numbers provide evidence, we sometimes fail to recognize that mathematical solutions need evidence of their own.  That being the case, students in math must also learn to provide evidence of their solutions as demonstrated in the CCRS here:

Ø  VIII.B.1.  Develop and evaluate convincing arguments.

One of the CRAs that students get quite involved in is “Bull’s Eye Math,” because it does not simply ask students to solve problems of area and probability, it invites them to create their own games. Students must develop a game based on their knowledge of geometric probability and must also explain and justify their solution, giving them practice in providing evidence.


We live in an era in which scientific facts are discussed on a daily basis, and sometimes these facts are taken out of context. Learning to discern reasonable and reliable evidence in science is necessary for understanding the world we live in.  Depending on evidence in science also helps students understand the kinds of information people want when considering various positions on an issue. The CCRS illustrate this point:

Ø  I.A.4.  Rely on reproducible observations of empirical evidence when constructing, analyzing, and evaluating explanations of natural events and processes.

A favorite among students and teachers alike, “Good Vibrations: Music Resounds with Physics!” asks students to experiment with systems in which standing waves are created in a string or spring via external vibrations. Students must determine what factors in each system determine the characteristic frequencies at which that system resonates—and they must try to identify the mathematical relationship each factor has to the resulting frequencies. In the end, students must explain how their conclusions are supported by their findings; in other words, they need to use evidence to explain what they report.

Social Studies:

Much of social studies centers on the idea that we need evidence in order to make helpful and judicious decisions about how we live as a society.  Without evidence in social studies, we can only guess how policies, cultural attitudes, and historical events affect people. In social studies, one demonstrates their ability to use evidence by making an argument.  As such, the standard in this field is:

Ø  IV.D.1.  Construct a thesis that is supported by evidence.

In “Presidential Speech Analysis,” students read and analyze a State of the Union address by a president of the United States. They then research the era in which the speech was written and policy goals discussed in the speech.  This allows students to gather evidence for a paper in which they must argue which powers were available to the president at the time and whether or not the president made promises that fell outside expressed powers.

Back to the Three Little Pigs

We all have opinions; they’re relatively easy to construct.  Like the straw house, though, they are also easy to knock down.  Providing evidence for an opinion can be much more difficult.  It requires us to think about other points of view, and sometimes the search for it causes us to change our minds. However, the skill to make informed decisions and solid arguments leaves you with a house made of bricks.  It might take longer to build, but it’s much stronger in the end.

The ability to recognize and provide evidence is a critical skill, mentioned again and again by higher education faculty when asked what students need to be able to do to succeed in their courses. We encourage you to explore additional CRAs on for other ideas on how to develop this valuable skill in your students.


This post comes to us courtesy of Dr. Leta Deithloff.  Dr. Deithloff helped develop many of the Social Studies CRAs and teaches Developmental Reading and Writing at The University of Texas at Austin.