## Saturday, October 13, 2007

### Project Idea: Independent vs. Dependent Variables

I realize that since I am a math teacher, it must seem like all of the ideas and lessons I have posted are designed for math teachers only. This is not my intention. This blog is for all teachers looking for new ways to help their students succeed in their content areas. My intent is to share ideas that are easily adaptable to any subject and don't require extraordinary funds or effort to implement. Indeed many of my ideas, including this project, have their roots in my years teaching social studies.

When I started teaching math I was disheartened by how downright boring most of the teachers around me were making it. I had used a wide variety of approaches to help my students be successful in U.S. History, and it seemed obvious that these same ideas would work in Algebra. Unfortunately for the students outside my classroom, I was more or less alone in this perspective. Nonetheless I adapted my old ideas to my new subject rather easily because most of them were painfully simple ideas designed to be easy for me to do and easy for them to understand and remember.

One of the easiest and most powerful ideas you can use to teach anything is a mini-poster project. When I hear "project" in most classes I think of giant poster paper or tri-fold science fair project boards which require weeks of work (or, like I did when I was in school, a lot of focused work the day before it was due).

The difference here is scale: students illustrate a "poster" no bigger than a standard 8.5" by 11" piece of paper. Thus the focus is off the process and back on whatever it is you want them to know and understand. Use it to help students remember simple concepts and vocabulary by illustrating them and providing examples or explanations. By touching on multiple intelligences--linguistic (words), spatial (visual), kinesthetic (artistic, creative), logical-mathematical (in math at least)--you help reach more students. As I tell my students, "these are easy ideas, but also easy to forget, so we do things like this to make sure we know what we need to know."

This example project is designed to help students understand the concept of independent and dependent variables. Understanding the difference is something 9th graders are tested on in Texas, but more importantly it helps created a deeper understanding of linear relationships and more complicated functions.

An easy way to introduce this idea is to talk about cause and effect relationships, which students discuss in English and almost every other class. At their most basic level, independent variables are the cause and dependent variables are the effect. You could make a lot of connections to comparisons students might find easier:

 Independent Dependent Cause Effect Before After Input Output What you do What happens

The idea of this particular project is that students will use two pictures (drawn or borrowed) to illustrate the relationship between independent and dependent variables. The project instructions contain numerous examples, but the premise is to have a picture of one thing that directly affects another, label them appropriately, and write a simple statement to explain the relationship (see the example above). I explain that this took all of 5 minutes to create after deciding on an example. Students are free to use any of the examples included or to create their own.

Most of the time you can assign this sort of project for outside of class, but it can also be used as independent practice or an alternative assessment to shake up your daily routine.

Grading is fairly easy; for those of you who like to create rubrics to keep things objective, these are the standard criteria:
1. Following directions: Did they include all of the elements required (pictures/drawings, explanation, labels)?
2. Clarity: Does their example make sense and is easy for others students to understand?
3. Effort: Did the student put in time and effort into making the poster colorful, attention grabbing, and easy to read and see from afar?
I always stress with mini-poster projects that they need to keep in mind the other students who will look at their posters on the wall to try to understand the concepts, so they need to make it easy for anybody to understand. This forces them to reach the highest level of Bloom's Taxonomy (evaluation). Thus a "simple" project becomes something much more meaningful.

Poster Project: Independent and Dependent Variables

I used this same project in September for adding, subtracting, multiplying and dividing integers. Students had to include an example (with a correct answer) and an explanation of how to do it. I have also had students draw parent functions for linear and quadratic equations, and illustrate other vocabulary from the word wall for extra credit.

These are just the math applications; in U.S. History I used almost the same project to illustrate that the states had more power than the federal government under the Articles of Confederation; students showed examples of one thing having power over another (cat vs. mouse, etc) and labeled them accordingly. They never forgot the significance.

Comments, ideas and questions are always welcome!

D²CRanch said...

Thank you for the idea. I will be using it tomorrow with 9th graders in Central TX.

TexasLinnea said...

I love these mini-poster ideas. I teach 8th grade pre-algebra and pre-ap algebra I. Eighth graders tend to be great at drawing and doodling. This could really grap the attention of those who find math boring.

Anonymous said...

Great idea for teaching such a difficult concept. I really like the idea of using multiple intelligences to assist in their understanding of the concept. Every year I begin teaching my science classes by reviewing the scientific method and this is one area they always struggle with. Thanks again for a creative way to hopefully make it easier for the students.

Anonymous said...

I used this idea to help a student in tutoring for my transitions to algebra class. He just wasn't getting it. I came online to fine more examples for him to practice. I came across this site and had him draw several sketches. By the end he actually got it!! Thanks!
(I wish I had read this before I taught the lesson in class! great examples and rubric)

Anonymous said...

This is a great project idea, however, the independent and defendant variables should not be linked as 'cause' and 'effect'. This is prevalent esp in science -- just because two variables are correlated does not mean that one causes the other (major student misconception)

Mr. D said...

An independent and dependent variable relationship is by definition cause and effect.

What you're referring to is a correlation, which we address more explicitly later when we plot collected data and examine scatter plots. Students are taught that there can be relationships that are not independent/dependent (or cause/effect), and of course these discussions do come up when we're doing the project and unit in question.

This project doesn't teach students that every pair of variables is independent and dependent (or by way of analogy, cause and effect). It teaches students how to identify these particular variables in a given situation, or more to your point, determining that there is no such direct relationship.

This is necessary in preparing them for linear relationships and other equations. Cause and effect is a completely valid and necessary analogy.

Anonymous said...

I'm using this tomorrow to explain the dependent and independent variables in sociology. It's fast, easy and gives them an interest in the topic with I can jump them into correlation and causation. Thanks so much!

Jess said...

I am a first year teacher (just finished my first week - yay!!) Thank you so much for this idea! My kids, that struggle with reading, will totally love it. And I hope the pictures will help them remember!

Gary said...

I love you! thanks from Miami

Nicolette SA said...

Hi Mr. D! I'm a third year educational student from South Africa. I've just found your website and I have to say I LOVE IT! We have a project on linear functions and you are helping alot. Teachers like you are an insperation for student teachers like me. Thank you!