Teaching independent investigations to 11–14-year-old students will help them become scientifically literate citizens and young scientists with a passion for the subject. A large part of this is by controlling the variables – such as participant age and gender, medical history, other current medications and even where they live. When carrying out clinical trials, scientists need to determine the efficacy of new vaccines. The recent introduction of a Covid-19 vaccine has put clinical trials in the press and at the forefront of everyone’s minds.
There has never been a better time to talk about controlled variable investigations.
#Control variable trial#
Here, medical lab scientists are working on samples collected in the Novavax phase 3 Covid-19 vaccine trial This helps to reduce any inaccuracies caused by the controlled variables.Controlling variables is key in real-life contexts such as clinical trials.
#Control variable professional#
To overcome this, professional scientists repeat experiments many, many times so that they can 'average' the results. The conclusions that you draw from any biological experiment should show that you understand this and suggest some of the places that inaccuracy could have come into your experiment through no fault of your own. same size pot, same amount of light and temperature and some other factors too. Even if you did use cloned plants, there are other factors that should be controlled to ensure a fair test, like using the same soil. But genetics of each plant should also be controlled by using clones. The plants you use is a variable that needs to be controlled so you use the same type of plant in all of your tests. You would need to do many different experiments.
For a start, there are many different fertilisers so the results could differ from one to another. Take the study of " Does adding fertiliser make a plant grow bigger?". That way, you can probably spot if it has had an effect on the results even if you can't measure it.Įxperiments in biology are actually very difficult to control completely. Where you do identify a control variable outside of your control, you should at least try to monitor it.
This can lead to a false correlation between the variables you studied but this is rare. In some cases, changes in a variable that have not been measured could actually be the cause of changes in the dependent variable. At other times, some important variables may be outside of your control or be extremely difficult to control. When this happens the results and conclusion may not be fully reliable. This GCSE Biology quiz is all about the third type.Types of Variables Quiz - Rapid Revision for GCSE BiologyĬontrolled variables make sure that your experiment is a fair test, but sometimes you may miss one of the control variables. In scientific investigations there are three types of variable - key independent variable (what you change), dependent variable (what you measure) and the controlled variables (factors you control to ensure they are the same throughout your experiment to make it fair).