A controlled variable is one that is held constant ... the independent variable and dependent variables. For example, in our imaginary experiment on the effects of sleep deprivation on test ...

For example, if you want to see how water ... the amount of water is the independent variable. In the plant experiment, controlled variables might include the type of plant, the amount of sunlight ...

A random variable is a number whose value is ... and can take on an infinite number of possible values. An example would be an experiment that involves measuring the amount of rainfall in a ...

So it languished for more than six months, until an engineer, who saw that the cost of writing the code for it would be small, launched a simple online controlled experiment—an A/B test—to ...