Biology: Biology Basics: 03: Independent Variable vs. Dependent Variable - Medical Animation
This animation may only be used in support of a single legal proceeding and for no other purpose. Read our License Agreement for details. To license this image for other purposes, click here.
Biology: Biology Basics: 03: Independent Variable vs. Dependent Variable - Medical Animation
MEDICAL ANIMATION TRANSCRIPT: Independent variable and dependent variable are important terms related to controlled experiments. Remember, a controlled experiment is a scientific test in which all conditions are kept constant except for the variable you're testing. The independent variable is the thing you're testing in an experiment. It's often abbreviated as IV, and sometimes called the manipulated variable because you change or manipulate this variable. In an experiment, the dependent variable is the thing you're observing and measuring, the thing you're anticipating may be affected as a result of exposure to the independent variable. It's often abbreviated as DV, and sometimes called the responding variable because it responds to the change that you make. Let's look at a few examples. Suppose your hypothesis is that if students study 15 minutes a night, then they will have higher test grades than those who don't study at all. What's being changed or manipulated? It's whether or not the students study for 15 minutes. And what's going to be observed or measured in this experiment? What do you think might be different as a result of this increased study time? You're expecting tests grades will be affected. In this experiment, the independent variable is the study time. And the dependent variable, the thing you're measuring or going to observe is the tests grades. Here's another example. See if you can figure it out. This time, the hypothesis is that if people who have headaches take aspirin, then they will get relief faster than those who don't take aspirin for headaches. So, what's the thing that's different in this case? The thing that's different, the independent variable, is whether or not somebody is taking an aspirin. Then what are you going to measure? You're measuring how long it takes for their headache to go away. That's the dependent variable. Here's a final example to help you understand these terms. You predict that if a brand name light bulb is left on continuously, then it will burn longer than a bargain brand light bulb used in the same manner. In this case, what is the independent variable? It's the brand name light bulb. What are you measuring? You're measuring how many hours the light bulbs work before burning out, which is the dependent variable. The independent variable is the brand name light bulb, and the dependent variable is the amount of time the light bulbs work before burning out. So, to review, the independent variable is the thing that you're testing. Sometimes this is referred to as the cost in an experiment. It is also the "if" part of your hypothesis. The dependent variable, the thing you're measuring, is the effect. It is also the "then" part of your hypothesis. [music]
"I wanted to take some time out to let you know what a wonderful job you did
with the 'collapsed lung/fractured rib' illustrations. They were both
detailed and accurate. My medical expert was comfortable working with them
and he spent at least an hour explaining to the jury the anatomy of the
lungs, the ribs and the injuries depicted in the illustrations. Needless to
say, the jury was riveted to the doctor during his testimony.
The jury returned a verdict for $800,000.00 and I'm sure we would not have
done so well if not for the visualizations we were able to put forth with
your assistance. Lastly, my special thanks to Alice [Senior Medical
Illustrator] who stayed late on Friday night and patiently dealt with my
last minute revisions."
Daniel J. Costello
Proner & Proner
New York, NY
"The Doe Report's Do-It-Yourself Exhibits program enables easy customization
of complex medical exhibits at a reasonable expense and in a timely manner.
Practically speaking, custom medical exhibits are no longer an unthinkable
luxury, but a routine necessity."
Jack S. Cohen
Levy, Angstreich, Finney, Baldante & Coren
Philadelphia, PA
"Medical illustrations are essential during trial for any medical malpractice case. The people at MLA have the uncanny ability of creating medical illustrations that simplify the most complex of medical concepts and human anatomy to a lay audience. The exhibits of MLA allow experts to easily describe complex concepts and human anatomy in a manner that could
not be done otherwise.
In addition, their custom illustrations show in great detail the extent of
injuries suffered and the devastating effects they have had on the client's
anatomy. These custom illustration can show, side by side, the body before
and after a catastrophic injury. The effect of this juxtaposition is
unmatched by any testimony that can be adduced at the time of trial.
Even jurors after trial have commented on the ease with which they grasp
medical concepts and anatomy once the MLA exhibits were introduced and
used by my experts. Even judges who have "seen it all" are thoroughly
impressed by the detail and sophistication of the illustrations.
"Thank you very much for the great work on the medical exhibits. Our trial
resulted in a $16 million verdict for a 9 year old boy with catastrophic
injuries, and the medical illustrations definitely played key role in the
trial."
Medical Legal Art creates medical demonstrative evidence (medical
illustrations, drawings, pictures, graphics, charts, medical animations,
anatomical models, and interactive presentations) for use during legal
proceedings, including research, demand letters, client conferences,
depositions, arbitrations, mediations, settlement conferences, mock jury
trials and for use in the courtroom. We do not provide legal or medical
advice. If you have legal questions, you should find a lawyer with whom you
can discuss your case issues. If you have medical questions, you should seek the advice of a healthcare provider.
