Scientific Method

What is the Scientific Method? The scientific method is an organized way to find a solution to a problem

What are the steps of the Scientific Method? Identify a problem Develop a hypothesis Design an experiment Collect and analyze data Draw a conclusion

Example Experiment Please Don’t Try This At Home!

The Tortoise and the Hare

Purpose Question/Statement Definition: The question that gets answered by the hypothesis and tested during an experiment. Must be testable Should start with “What is the effect of ________ on ________?” or something similar. Can also be a complete sentence: “The goal of the experiment is to…” Example Purpose Question: What effect do energy drinks have on the tortoise?

Hypothesis Definition: Prediction about what will happen during an experiment. Must be testable If (independent variable), then (dependent variable), because (research or prior knowledge). Example hypothesis: If the tortoises are given energy drinks, then the tortoise will be able to run faster for a longer period of time, because it will effect the tortoise’s heart rate and central nervous system.

Materials Definition: List of the items you need to complete the experiment (including Measurement equipment). Should also include how much of each item is needed. 20 Tortoises 5 4-meter long tracks Stopwatch 3 different energy drinks – 250mL Monster – 250mL Red Bull – 250mL 5 Hour Energy 30 50mL Syringes 10 kg Tortoise food 10 L tap water

Variables Independent Variable: Definition: Factor in an experiment that causes the change. (factor being manipulated) Should be the only difference between your experimental groups and control group. – Example independent variable: Type of energy drink Dependent Variable: Definition: Factor in an experiment that changes because the independent variable changed. Should be What you are measuring and observing during an experiment – Example dependent variable: Speed during the 4m race

Constants Definition: Any factors that are the same between your experimental groups and control group. Should be a long list. Commonly includes things like temperature, light, time, size, etc. Example constants: Tortoises (same sex, age, size, number) Environment (same cage, food, water, room) Exercise (same amount, intensity, type) Racing and Timing Technique (same stopwatch, method, at same time)

Groups Control Group Definition: Group in the experiment that does not get tested on. - Used to get a baseline for comparison - Some experiments do not have a control group if you are only comparing objects to each other. Example Control Group: 5 Tortoises with water Experimental Group Definition: Group in the experiment that does get tested on. – Example Experimental Group: Tortoises with energy drink (15 total) – 5 use Red Bull – 5 use Monster – 5 use 5-hour-energy

Procedure Definition: Step-by-step directions about how to do the experiment.  Should also include what data must be collected and how to collect it. Example procedure: Place each group of 5 tortoises, none of which have had an energy drink, on track and allow them to finish the course. Record times. Let the tortoises rest for 2 days. Place the control group on the track and time their races again. Record times. Give 50mL of the energy drink to each of the 3 experimental groups 20 minutes before their race. Place experimental groups on the tracks one at a time and record race times. Collect all data in a chart and compare the control group and the three experimental groups.

Data Tables Definition: Organized grids where information is written down during an experiment.

Data Tables Must have a descriptive title, axis labels, and units.

Inferences Definition: An explanation for why something happened or what is being observed.  Observations + prior knowledge = inferences. Example inference: The energy drinks caused the tortoises to race faster because they increased heart rate and influenced the central nervous system 5 Hour Energy caused the tortoises to run the fastest because it is the most concentrated and has more of the substances that influence heart rate and the central nervous system.

Conclusion Definition: Summary statement at the end that recaps what happened in the experiment.  States whether hypothesis was supported or rejected and includes the reason why. Example Conclusion: The hypothesis was supported because the energy drinks decreased the tortoises’ race times. (increased speed) Also, it was shown that Monster and Red Bull give about the same energy boost, but 5 Hour Energy gives a significantly larger energy boost.