- Controlling factors
Naturally, the factors that can be controlled in any experiment are very much dependant on the type of experiment you are doing, and so this question is difficult to answer without knowing further details of your situation or outcome that you wish to research.
- Why it is important to control factors in an experiment
Factors need to be controlled when conducting an experiment so that we can ensure that they are not having an impact upon our overall result.
For example, if we were looking into how temperature affects the rate of photosynthesis (the ability of plants to turn light energy into chemical energy), we would need to keep other factors that are known to have an effect, such as light density and carbon dioxide concentrations, the same throughout our investigation. By doing this we can be fairly certain that it is the factor that we are purposefully changing that is giving us our change in results, and so can say that we have conducted a reliable investigation.
- The difference between independent and dependant variables
When it comes to scientific experiments, variables are the same as factors in most cases. However there are two different types of variables: Independent and dependant and, although most people get confused between the two, the clue is in the name when deciphering which is which!
An independent variable is a variable that is not controlled or affected by any other variables in an experiment. For example, in the photosynthesis investigation, light would be an independent variable as it can be changed just by changing it.
A dependant variable however, is just that: Dependant. To change it we must change one of the other variables. The rate of photosynthesis would be a dependant variable, as it is controlled by factors such as light.