/-/https/www.sciencebuddies.org/cdn/Files/21464/5/sb-logo.png){kind=logo}
/-/https/www.sciencebuddies.org/cdn/Files/21464/5/sb-logo.png){kind=logo}
I am testing the effects of energy drinks on the resting heart rate of teenagers. I have two groups--1 that consumes caffeinated products regularly and 1--that is does not consume caffeine. Is it ok to use three different brands of energy drinks that have the same amount of caffeine as long as I use the same energy drink in each group on the same days or should i use the same drink each time?
Am i correct when i say that the energy drink is my independent variable and the heart rates are the dependent variable?
Is the caffeine free group my control group, i have read articles but am confused with the control?
Energy Drink Effect on Heart Rate
Moderators: AmyCowen, kgudger, bfinio, MadelineB, Moderators
-
sportsfan1995
- Posts: 1
- Joined: Wed Jan 16, 2008 10:34 am
- Occupation: Student
- Project Question: Energy Drinks: The Effect on the Resting Heart Rate of Teens
- Project Due Date: 2-15-08
- Project Status: I am finished with my experiment and analyzing the data
-
deleted-71256
- Former Expert
- Posts: 64
- Joined: Fri Sep 02, 2005 6:43 pm
- Occupation: NASA Computer & Cognitive Scientist
- Project Question: n/a
- Project Due Date: n/a
- Project Status: Not applicable
Re: Energy Drink Effect on Heart Rate
Hi,
You've started to grasp how to think about the variables. Let's start over with the question and see how things sort themselves out. You want to know how energy drinks affect resting heart rate? You say that you are interested in the difference between people who use caffeine regularly and those who do not. So that's an independent variable. (See https://www.sciencebuddies.org/science- ... bles.shtml for further discussion.)
I am unsure whether you are interested in the effect of different kinds of energy drinks (that's your choice). If you're not interested in the effect of the brand or type of energy drink, then you will hold that constant -- you will want to use the same energy drink with each person. That is, the type of energy drink is "controlled" -- it is not allowed to change. If you are interested the effect of different energy drinks (given that they have the same caffeine amount), then the drink is an independent variable.
As you indicated, you are interested in what happens to the heart rate -- according to your hypothesis, it might vary depending on the person's history. So heart rate, as you indicated, is a dependent variable. I like to write this using a kind of set notation -- { PERSON } is the set that is changing, with a subset of caffeine users and non-caffeine users. If you were experimenting with the drink also -- allowing it to change -- we'd express the experiment this way -- { PERSON X DRINK }. So if you tested 10 people on 3 drinks, that would be 10 x 3 = 30 trials.
You mentioned the idea of a "control group." This is a subset (e.g., of people) that is not subjected to the experimental treatment, as a way of showing that the independent variable is actually responsible for what you are observing. For example, in drug tests, patients are given a placebo (such as a sugar pill). Suppose we are interested in side-effects from a new drug, such as headaches. Then if we find that say 8% of the placebo patients get headaches -- even though we did nothing to them -- and 9% of the patients given the new drug have headaches, then we have evidence that the headaches are not caused by the new drug.
In your case, you might consider testing with a drink that looks like an energy drink, but doesn't have caffeine, so you have evidence that is the caffeine that is making a difference. You can find information about control groups at this site -- http://en.wikipedia.org/wiki/Scientific_control
Probably the main trick for thinking about variables in a case like this is to revisit your hypothesis and be sure it states precisely what you are interested in knowing.
Bill
You've started to grasp how to think about the variables. Let's start over with the question and see how things sort themselves out. You want to know how energy drinks affect resting heart rate? You say that you are interested in the difference between people who use caffeine regularly and those who do not. So that's an independent variable. (See https://www.sciencebuddies.org/science- ... bles.shtml for further discussion.)
I am unsure whether you are interested in the effect of different kinds of energy drinks (that's your choice). If you're not interested in the effect of the brand or type of energy drink, then you will hold that constant -- you will want to use the same energy drink with each person. That is, the type of energy drink is "controlled" -- it is not allowed to change. If you are interested the effect of different energy drinks (given that they have the same caffeine amount), then the drink is an independent variable.
As you indicated, you are interested in what happens to the heart rate -- according to your hypothesis, it might vary depending on the person's history. So heart rate, as you indicated, is a dependent variable. I like to write this using a kind of set notation -- { PERSON } is the set that is changing, with a subset of caffeine users and non-caffeine users. If you were experimenting with the drink also -- allowing it to change -- we'd express the experiment this way -- { PERSON X DRINK }. So if you tested 10 people on 3 drinks, that would be 10 x 3 = 30 trials.
You mentioned the idea of a "control group." This is a subset (e.g., of people) that is not subjected to the experimental treatment, as a way of showing that the independent variable is actually responsible for what you are observing. For example, in drug tests, patients are given a placebo (such as a sugar pill). Suppose we are interested in side-effects from a new drug, such as headaches. Then if we find that say 8% of the placebo patients get headaches -- even though we did nothing to them -- and 9% of the patients given the new drug have headaches, then we have evidence that the headaches are not caused by the new drug.
In your case, you might consider testing with a drink that looks like an energy drink, but doesn't have caffeine, so you have evidence that is the caffeine that is making a difference. You can find information about control groups at this site -- http://en.wikipedia.org/wiki/Scientific_control
Probably the main trick for thinking about variables in a case like this is to revisit your hypothesis and be sure it states precisely what you are interested in knowing.
Bill