Change no more than one. Otherwise, you can't tell which changing variable is having the observed effect.
Ideally, you should change only one variable at once.
Sometimes in the real world this isn't possible for any of a variety of reasons (one example is if you're measuring things where you have no control over the input, where you pretty much have to take whatever data you can get). However, in such cases you've got to make at least one more measurement than the number of variables that are changing and solve a system of simultaneous equations. It's a lot more complicated, and may not be possible unless you're absolutely sure you've got the underlying theory worked out (for example, if the dependence on a given variable might be linear, quadratic, or something else, this probably won't work at all, and at the very least you should get a lot more observations to confirm that things are working the way you think).
Ideally, an experiment should test only one variable (the independent variable) at a time. If you have two or more variables changing at the same time you have no way of knowing which variable is causing your results.
The purpose of a control variable in an experiment is to allow the experiment to come out with accurate results. It makes it a lot easier to measure the results when different things aren't affecting it.
Controlling for a variable is the act of deliberately varying the experimental conditions in order to take a single variable into account in the prediction of the outcome variable. Controlling tends to reduce the experimental error. A control is something that does not change in the experiment.
The independent variable is the part of the experiment that is being tested or the part that is changed by the person doing the experiment. The dependent variable is the part of the experiment that is affected by the independent variable.
Anything that can be changed in any way is a variable. so,,,,,an infinite number. Day, time, heat, light, humidity, speed, what you ate for dinner the Wednesday before you go shopping. So, quite literally, an infinite number. Hope this helps.
Environmental factors if you cannot control them.Variable factors if you can control them.See link below for easy explanation:In an experiment the scientist is able to change the independent variable. To insure a fair test, a good experiment has only one independent variable. As the scientist changes the independent variable, he or she observes what happens. - See more at: http://www.chacha.com/question/what-part-of-an-experiment-is-the-factor-that-you-change#sthash.iyH25Jac.dpufIn an experiment the scientist is able to change the independent variable. To insure a fair test, a good experiment has only one independent variable. As the scientist changes the independent variable, he or she observes what happens. - See more at: http://www.chacha.com/question/what-part-of-an-experiment-is-the-factor-that-you-change#sthash.iyH25Jac.dpuf
There are complex models that allow researchers to study several variables if the experiment is carefully designed and very carefully carried out. These models can show whether a variety of variable interactions occur, and if that is your focus then these models are good. But the best experiments investigate a small number of variables, as few as one.
Ideally, an experiment should test only one variable (the independent variable) at a time. If you have two or more variables changing at the same time you have no way of knowing which variable is causing your results.
To ensure a good experiment is conducted effectively, it is necessary to have a clear hypothesis, carefully controlled variables, a well-designed procedure, accurate data collection methods, and thorough analysis of results. Additionally, proper documentation and replication of the experiment are important for validity and reliability.
The purpose of a control variable in an experiment is to allow the experiment to come out with accurate results. It makes it a lot easier to measure the results when different things aren't affecting it.
A good experiment needs to be a fair test so to have a fair test you need to have a independent variable, a dependent variable and a controlled variable. Independent Variable: The thing you change Dependent Variable: The thing you measure Controlled Variables (there's usually more than one): The things you keep the same. For example if I have 3 kids and I want to find out who can open presents the quickest the independent variable: would be what kid is opening the presents the dependent variable: would be how quick the kids were so their time and the controlled variables: would be the size of the present they used and the wrapping paper on it. Also a experiment should be repeated twice for the best results and then averaged. A bad experiment wouldn't be a test for example changing what should be a controlled variable so if one kid had to open a bigger present than the other kid they would take longer than they would with the same size present so you wouldn't get good results.
x = 2 y = 4 x + y = 6 change the variables x = 4 y = 4 x + y = 8 Take 1 kg of TNT and it will be a good sized bang. Take 1 ton of TNT and it will level a city block.
A good experiment should have a limited number of variables, typically one or two, to ensure that the relationship between the variables can be clearly identified. Having too many variables can make it difficult to determine which factors are influencing the outcome of the experiment.
an experiment that can be controlled i did not know this That is not a good answer! A controlled experiment is: If you set up an experiment: Example: You have two plants. You want to know if fertilizing every day causes it to grow more. In your experiment everything has to be the same! Except one thing. You have to have the same type of dirt and pot and flower/vegetable. You have to water each of them every day. But, you fertilize ONE of them once a day until your results are clear to you, or when you want to stop testing. This way, you can see how the fertilizer effects the plant growth compared to just water every day. If you change more than one thing, like how much you water the plant, it is not a controlled experiment anymore. because then you won't know which variable (thing that you have changed) is taking effect. You wouldn't know if it was more water or the fertilizer, or both that is making the plant grow faster!
Controlling for a variable is the act of deliberately varying the experimental conditions in order to take a single variable into account in the prediction of the outcome variable. Controlling tends to reduce the experimental error. A control is something that does not change in the experiment.
The independent variable is the part of the experiment that is being tested or the part that is changed by the person doing the experiment. The dependent variable is the part of the experiment that is affected by the independent variable.
Yes. A good example of which is the Ideal Gas Law. PV=nRT You have four variables and one constant.