VARIABLES
Taketime to identify your variables before you start your experiment. It will
helpyou to write your procedures. A variable is something that can change or
bechanged. There are three kinds of variables: independent, dependent and controlledvariables.
Ina well-designed investigation, there should be only one thing changedon purpose, called theindependent or manipulated variable.
Rememberthe example question: Does soaking bean seeds before planting
affecthow fast they will grow?
Inthis example, the thing I am changing on purpose is the soaking the someof
thebean seeds before planting them. Therefore, the soaking of the seeds beforeplanting is the independent variable (manipulatedvariable).
WhatI think or hope will change during the experiment is called the dependentvariable or responding variable.
Inthis example, the thing I am hoping or thinking will change during the
experimentis how fast the plant grows. Therefore, how fast the plant grows isthe dependent variable (responding variable).
Imust try to keep any other things that might be changed the same
throughoutthe experiment. These things that I keep the same are called the controlledvariables.
Inthis example, the things I would keep the
sameare:
Type of bean
Amountof water for soaking the seeds
Typeof soil I plant the beans in
Amountof soil I plant the beans in
Amountof water and sunlight they get
everyday
Sizecontainers I plant the beans
Theseare the variables I am controlling.