what is a controlled experience (science ?)?

Answer 1

I think you mean controlled experiment?

If you do, that means that when you run a test, say testing a new drug, you give the drug to an experimental group and you don't give it to the control group so that you can determine whether or not the drug is having an effect. If there were no control group you couldn't say for sure if it was the drug having an effect or if it was just a general trend in the experimental group that could be attributed to any number of factors.

Answer 2

In any scientific exploration, to prove the validity of our results, we need to proof that what we did resulted in something...i.e. I just found a cure for some terrible disease...so we select a number of patients (as much alike as possible...that's why we use mice, rats and such animals as we can obtain same weights, age, etc)...then we divide the test group into two or perhaps even more groups. The actual identity of the drug is hidden from the personnel giving it and we also use placebos (useless medication...perhaps sugar or even salt pills or injections). All patients are treated the same except for some being on the real medication. At the end of the test, the results are revealed and studied to determine if any real cure had taken place. Obviously if 90% of the people on the real medication were cured, then the drug has great merit...if the results were indifferent, then it can be attributed to the ineffectiveness of the drug, or psychological responses unrelated to the drug (what some might term self-healing). In toxicology we use a similar technique to test venom potency and rate it in LD (lethal dosage). We use standard sized animals and inject the animals with a tiny amount of venom and increase the amounts (over a period of time until we reach LD50 (meaning that 50% of the animals died) and finally we reach an LD100 (all died). From knowing precisely the amount injected, we can extrapolate the amount that would be lethal to a normal human. So we can predict with reasonable certainty that this spider or scorpion would be deadly...knowing the venom yield of a normal animal or whether it is simply a painful experience but not life threatening. This is a controlled experiment in medicine.

Answer 3

A controlled experinece is a type of experinece that while a group is left untouched (control group) other group is experimented with a special fact, or an independent variable then the effects are compared between two groups within a time span. For example, a group of chickens listen music and other group doesnt listen. At the end of the day the effect of the music on production is measured by the comparison of two groups. This type of experinces are widely used in scientific researchs.