practicals

• an independent variable is what you change
• a dependant variable is what you are measuring
• a controlled variable is what you keep the same
• independent variable for the caffeine practical?

  caffeinated or decaffeinated drink
• dependant variable for the caffeine practical?

  reaction time
• controlled variable for the caffeine practical?

  volume of drink

  age
• why do the people have to wait 15 minutes after having the caffeinated drink?


  to allow the caffeine to get into the bloodstream