Scientific Method Step 3 (pg. 15) :  The first step of the scientific method is to ask/create a good question  The second step requires you to gather information  The third step of the scientific method attempts to determine what the answer is. It is called an hypothesis or an educated guess because it should be a reasonable answer. It is possible to have more than one answer for any given problem.  See 4 examples on page 15 of the Skills Booklet.

Scientific Method Step 3: Hypothesis - Make an educated guess of an answer to the question - Needs to be based on scientific research - Format:  If...then...because…..  As...then…because…. I

“If…..then…..because” A hypothesis is a possible explanation or a prediction for an observed cause-effect relationship. Often it is worded “If …….. then …….... because” or “As …… then …. because”. The “IF” part of the statement is the cause variable (independent variable), and the “THEN” part of the statement is the effect variable (dependent variable). Eg. If more heat energy is added to the water, then the water will come to a boil faster because the water particles will be moving faster. Eg. As a student studies more, then their marks will improve because they have a better understanding of the material.

Hypothesis If sticks of gum are used, then 23 pieces will fit in the mouth, because they will stack on top of each other reducing the amount of space needed. If the sugar in apple juice increases boiling point, then apple juice will boil at 105 o C, because it is similar to water (100 o C). If a cactus lives in sandy soil, then a cactus should get 300 mL of water each month for optimum growth, because the water will drain quickly due to the large particles of sand. If shampoo is not used then human hair will grow faster, because there is less residue build-up on the hair follicle. If protein is eaten at breakfast, then it will keep you feeling full of energy, because protein is used in every cell. Your turn…..see page 15 to practice your own!

NOTE: You do not have to use only one sentence. Example:

Will the paper be dry? Develop a hypothesis for whether the paper at the bottom of the cup will be dry or wet.

Skewers in a balloon. Develop a good question. Develop a good hypothesis.

Scientific Method Step 4a (pg. 16) : Designing Experiments in Science Most experiments in science are correlational studies: experiments which look at the relationship between two variables Variable – something that can change

3 types of variables: 1) Independent Variable (IV) - the “cause”/manipulated variable - the variable which the experimenter deliberately changes 2) Dependent Variable (DV) - the “effect”/responding variable - the variable which the experimenter measures NOTE: There will only be one IV and one DV

3) Control Variables (CV) - variables that we do NOT change in the experiment - they could change but are NOT allowed to Ask the question: What does the scientist have to do in order for this to be a fair test? -Practice Identifying Variables on page 16 of the Skills Booklet. -Read Scenarios and identify variables on page

Using the Scientific Method (pg. 19): Step 1: Initiate and Plan: What happens when……? How would I measure…? observation

THE DV IS: Using the Scientific Method: Step 2: Brainstorm List any variables that could affect your DV (chosen in the starburst) VARIABLES AFFECTING THE DV:

Using the Scientific Method (pg. 20) : Step 3: Fishbone: Experiment Organizer CV DV CV I I T U T U IV

Using your Starburst, plan out your variables for one of the following questions: What factors affect the boiling of water? What factors affect the lid popping off? When your fishbone is complete, you should be able to formulate a GOOD hypothesis, based on the variables chosen and using the general format: If ___(IV)___then___(DV)___because……. Let’s PRACTICE …………………………