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Testing a hypothesis

A valid hypothesis must be testable. It should also be falsifiable     , meaning that it can be disproven by experimental results. Importantly, science does not claim to “prove” anything because scientific understandings are always subject to modification with further information. This step—openness to disproving ideas—is what distinguishes sciences from non-sciences. The presence of the supernatural, for instance, is neither testable nor falsifiable.

To test a hypothesis, a researcher will conduct one or more experiments designed to eliminate one or more of the hypotheses. Each experiment will have one or more variables and one or more controls. A variable     is any part of the experiment that can vary or change during the experiment.

To test a hypothesis, a researcher will conduct one or more experiments designed to eliminate one or more of the hypotheses. Experiments typically have a dependent variable     , independent variable     , and several controlled variables     . The dependent variable is some changing aspect of the experiment that you want to find out. For example, if you're testing how a particular drug dosage fights cancer, your dependent variable could be how many cancer cells died. Your independent variable is what you changed to get that result. So in this example, your independent variable would be the different dosages of the drug. A controlled variable is any part of the experimental setup that you kept the same. The more controlled variables you have, the more accurate your data is likely to be. For example, in the drug dosage experiment, maybe you only tested pancreatic cancer patients, who were 60-70 years old, and had an early-stage diagnosis. If you had NO controlled variables, you couldn't be sure whether your results are due to the different drug dosage or something else.

The control group     contains every feature of the experimental group except it is not given the manipulation that is hypothesized about. Therefore, if the results of the experimental group differ from the control group, the difference must be due to the hypothesized manipulation, rather than some outside factor. To go back to our previous example, if you had a collection of patients who all received a certain dosage of the drug, and another group who did not receive the drug at all, the latter group is the control group. It's important to use control groups to know whether your experiment results are real. For example, if you saw no difference in cancer cell death between the group who received the drug versus those who did not, that is a clear result indicating the drug at that particular dosage is ineffective. The group who received no treatment is called a negative control     , and in drug studies, these groups often receive a placebo     , which is a pill/liquid that looks like the drug, but does not actually contain the drug. It contains nothing, or maybe a sugar solution that has no effect on the body. A positive control     is a sample/individual or group of samples/individuals who you know will actually demonstrate a difference from the negative control. For example, if you were comparing a new cancer drug to a known drug that works, the individuals receiving the known drug would be the positive control group.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
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Source:  OpenStax, General biology part i - mixed majors. OpenStax CNX. May 16, 2016 Download for free at http://legacy.cnx.org/content/col11749/1.5
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