Identifying the parts of an experiment that can change. Variables Identifying the parts of an experiment that can change.

Independent Variable What is being tested What is changed or chosen by scientist (What I change…)

What is the Independent variable? You measure the growth of your hair each month for one year. Time - Independent

Dependent Variable What is observed What is measured The data collected (What do I measure?)

What is the dependent variable? You measure the growth of your hair each month for one year. hair length - Dependent

Control The “normal” part of the experiment. Used to compare results. Example: The plant that has only water.

Constant Things that could change but are… Kept (the same) These allow for a fair test. (What stays the same?)

What are the constant variables? You measure the growth of your hair each month for one year. Person Hair condition (no new products, style) Measurement tool

hypothesis An educated guess at the outcome of an experiment which will be tested. Parts: If hair is colored (what will change= independent) Then colored hair will grow less (what will happen = dependent) Because hair color has harsh chemicals that damage hair preventing growth. (why based on prior observations or text)

Experiment Question = Does increased sleep cause higher grades? Example hypothesis If, then, because statement Experiment Question = Does increased sleep cause higher grades? Hypothesis – If the amount of sleep is increased then the grade average of students will increase because sleep allows students to be alert and focused in class.

Highlight the following: If = What is changed about the independent variable Then = what happens to the dependent variable Because = explain why the dependent will change