Along with better tennis weather, Spring is science fair time in the United States and our editor-in-chief, Dr. Cliff Kurtzman, suggested a column on tennis science fair projects. Most educators, from elementary school to the major universities, encourage students to pick a topic of interest. Conducting a tennis science project is a great way for a young player to learn more about the sport while fulfilling a classroom requirement. They'll learn some science and math and also have some fun.
In this column we'll provide some tennis science fair project ideas, information on how to conduct experiments, helpful hints and note a few common experiment pitfalls. While suggestions are made for high school students, the column focuses on experiments for elementary and middle school students.
Tennis Players Are "Natural" Experimenters
A "science experiment" might sound like a hard or even scary thing to try. But you've probably done most of the same activities and possess many of the same skills that scientists and engineers use to study a problem. If you play a sport or have a hobby you're typically a "natural experimentalist" - you just may not have thought of it that way.
Let's say you're trying to make sure your return does not go outside the court boundaries. You're hitting the ball with no spin each time and the ball is going out of bounds each time. What do you do? YOU EXPERIMENT! Hit the ball with less force or add some topspin, right? (Perhaps, you could investigate how spin affects the distance the ball travels?)
Let's take a different example. Maybe you like paper airplanes. You fold one and play - you actually "experiment" with it. What happens if you bend one wing down and not the other? What if you add some weight to the nose or tail with a paper clip? How does the plane react?
You may not have recognized this before, but there is a lot of natural experimentation when you "play."
Selecting A Topic - Forming A "Hypothesis"
How do you come up with a tennis science project idea? Sometimes it's not easy. Looking through books or magazines on tennis sometimes helps spur ideas.
One way to come up with a topic is to start asking the following questions: "What," "How," "How Much," "Which." Watch a professional match. Watch your friends play. Observe your own game. Bounce or throw a tennis ball. Look at different courts or tennis equipment. Do you have any questions about these?
How does the first serve differ from the second serve? Is it typically faster or slower? How much faster or slower?
Which is better - lose or tight strings? (And what does "better" mean? More control? More power?)
What would happen if the tennis ball didn't have fuzz on it?
Do all balls bounce the same? What makes a ball go faster on a return: a lighter racket, a stiffer racket, tighter strings or a faster racket head speed?
If one of your friends always gets their first serve in and another friend doesn't - what are your friends doing differently?
How can you determine an answer to these questions? Most often this entails setting up a repeatable situation where only one factor is varied at a time.
For example, the question may be "Does a ball bounce differently on a grass court versus a hard court?" You could launch the same ball, with the same ball machine, set to the same spin and speed located at the same court position on a grass court and then a hard court on a day with no wind. Thus, the only variation is the court.
You'll often read that you must have a "hypothesis" to prove when you conduct research; that is not necessarily true. There are forms of research that are exploratory in nature that do not have to be proved. So sometimes it is simply more applicable to state that you are investigating or studying a subject.
Another important point to keep in mind as you select an area to investigate is your timeframe and your budget. When is the project due and will you need to spend any money to answer your chosen question? Make sure that the problem is manageable and fits in your timeframe and budget. Downsize - make it smaller as
Here are some links to some tennis science projects that might be helpful:
Tennis Sport Science Lesson Plans, Tennis Sport Science Curriculum Links, and from the Society of Women Engineers - Motion Math and Motion Capture and Analysis. Another is the ball bounce experiments in the
October and November 2002 Tennis Server columns.
Planning Your Project
Your project plan should contain some of the same information that you would find in a recipe, a budget and a blueprint.
Let's look at each of these:
What type of information is found in a recipe?
- A list of ingredients - both the type of ingredient and the amount. For example: a cup of sugar or a teaspoon of vanilla.
- A set of instructions. For example: "Mix the flour and sugar together," "Add the milk."
- Tools that you need. For example: cookie sheets, measuring spoons or a
- Your end product. For example: MONSTER CHOCOLATE CAKE - makes 4 servings.
When you conduct your experiment you will need supplies (ingredients) and tools. You'll also need a list of instructions that you will use to get you from Point A (the raw ingredients) to Point B (the finished product - the MONSTER CHOCOLATE CAKE).
The Budget - Your Money and Time
As you develop your plan you will probably need to make a budget. There may be things to purchase. You'll want to know if you can afford to do your project. Sometimes schools have limits on how much money can be spent on a science fair project. Businesses are run with budgets. Budgets are needed to determine if a project can be afforded and those budgets are monitored carefully. If the maximum amount of money you can spend is $30 and you've already spent $25 of it (and there are still 20 items on your list to purchase) you may have jeopardized your project (or at least your wallet)!
Sometimes there are lots of "hidden costs" in a project. Remember the recipe? The ingredients asked for "1 cup of sugar" and "1 teaspoon of sugar." Okay, you'll need to buy or have on hand sugar and vanilla. The hidden costs may be the "tools." Do you have a measuring cup and teaspoon?
Careful planning to identify these hidden costs will help you here! To reduce costs you may want to borrow what you can or see what you have around the house that you can use. You may also be able to get samples or scrap items from businesses, if you let them know that it is for a school project.
So, as part of your plan you will need a materials list. What do you need: new tennis balls, poster board, colored markers, tape measures, film, a video camera? Some of these things you may need to buy; others you can possibly borrow.
List everything; add up how much these items will cost. It may be more than you expected. DON'T PANIC! Look at it again! Do you really need everything? Can you borrow any of the items? Can you substitute something that you have readily available for something else on your list?
You will be surprised how clever you become when your budget is tight!
Planning your time is important for another very practical reason. You want to be able to finish your project on schedule and enjoy it as much as possible. Have you ever been in a situation where at the last minute something went wrong and you didn't finish your homework on time? Or maybe you just waited until the last minute and didn't give yourself enough time to do a science fair project. Not only do you feel disappointed, but sometimes you just feel so rushed! You promise yourself - "next time I'm going to start earlier."
Here's a few tips:
1. Try and work on your project at least a little bit everyday. Even if you don't make much progress you are still farther along then you were yesterday.
2. Try and write your report as you go along; or write what you accomplished everyday in a journal. Writing your report as you conduct your project will help reduce the amount of work you have to do in those last days of your project. It also serves as a reminder of "where you left off" if you can't work on your project everyday.
The Blueprint - Your Instructions
For every experiment we conduct we developed a "test script." It contains a list of our materials, tools and instructions (our recipe) and a blueprint of how our experiment should work. You might want to look at the tennis lesson plans noted above or specifically look at the
Hot and Cold Tennis Ball Experiment. These plans might give you some ideas on how to write up your plan.
Test plans or scripts are a great way to have others review and critique your work. For example, before our team went to the USTA training center to conduct these experiments, we were asked to document what we would be doing and submit that documentation for the USTA sports scientists to review. We were all set! We simply sent the USTA our test scripts.
Having these instructions serves multiple purposes:
it makes a nice addition to your science fair display or report;
it communicates the steps you are taking to your teacher;
it makes the experiment process repeatable.
Finally, before you get ready to conduct your experiment we'll discuss a couple of common "pitfalls" when creating experiments.
I believe that the biggest pitfall is when students either knowingly or accidentally vary too many of the science experiment's parameters at one time.
Sometimes tennis projects require the ball to be launched in the same manner every time. Sometimes students want to hit the ball themselves, hoping that they will hit the ball the same each time. Of course, this is very difficult to do and judges and teachers also will question if you were really successful.
One alternative is to use a ball machine. Another is to make a ball "slingshot"- the slingshot is hammered into the ground and the "sling" pulled back to the same
position each time.
Another common pitfall is changing too many things in your experiment so that you cannot determine the "cause and effect." Let's examine a serve experiment. You decide that part of your experiment will be to see how your friend serves with different rackets. Perhaps some are heavier than others. Perhaps some of the rackets you test are strung tighter or loser than others. Your friend tests the different rackets and you see that they do better with a couple of different rackets - but there is no real pattern. How will you make your conclusion? Sure you can say your friend did better with Brand XYZ strung at ABC number of pounds - but why did they do better with the racket?
You have had too many "variables" in your experiment. First of all, your friend is not a machine. Not every serve will be hit with the same exact stroke pattern and power. Your friend gets tired after a while, also. By using different rackets strung differently you may also have added too many variables (changes) into the picture. Perhaps, instead you could start with one racket and have it strung differently and compare the results. (This is still a really difficult experiment to analyze because of the "human factor").
Another common mistake made is defining an experiment that cannot prove the point that you want to make.
a "yes" or "no" answer, i.e., "yes, the ball speed slows down after the bounce";
a trend in your data, i.e., "we noticed that the angle after the bounce was much lower for the French Open ball than the US Open ball";
some type of classification, i.e., "we categorized (sorted) the stroke patterns for the men versus the women players";
an observation to note, i.e., "our wind tunnel test showed how back spin and top spin fly differently through the air"; and/or
an ability to quantify your results with numbers, i.e., "25% of the players did the following."
When you analyze your experiment you'll be looking for a way to prove your idea or hypothesis. You'll be looking for:
Consequently, your analysis could include:
sorting and classification;
taking averages, means, standard deviations, or other statistical analysis; and
This is also an area where experience is important. Students should not hesitate to review their results with parents, teachers, a coach or other person they feel can shed light on the interpretation of their results. Professional researchers, scientists and engineers very often have their colleagues review their results.
My favorite lesson, by far, is the Hot and Cold Tennis Ball Experiment. Even the youngest tennis scientists (with adult supervision due to the heat and the cold) can conduct this experiment and understand it. It is inexpensive to conduct and takes
very little time. There are many variations to this experiment that the kids derive on their own: compare new balls to worn, old or pressureless balls.
For middle school students I think examining ball bounce angles on different
types of courts is a great experiment (see September,
October and November 2002 Tennis
Server columns) and for high school students I think
tennis biomechanics experiments are appropriate.
Good luck with your project and let me know how it goes.
Until Next Month ... Jani