Getting Started

1. Getting Started • Warm Up Handout • Learning Goal handout. • Take out the handout titled “Biology Learning Goal Scientific Method” • Notebook

2. Take My Word For It • The Earth is the center of the universe. • The sun revolves around the Earth. • All matter is made up of 4 elements: fire, water, earth, & air. • Bowling balls fall faster than basketballs because they are heavier. • The Vietnam war was about preventing the spread of communism. • Hugo Chavez was a dictator. • High-fructose corn syrup is a safe alternative to sugar. • So is saccharine, and Nutrasweet, and sucralose, and dextrose • Sadaam Hussein had weapons of mass destruction. • Milk is just as safe today as it was 50 years ago. • GMO’s pose no threat to your health. • 7-up is made with 100% “all natural” ingredients. • What do all these have in common? • Highly debated statements that have been delivered to people as fact.

3. Warm Up Discussion Answers • The world was once thought to be flat. Discuss with a partner the following questions and answer: • Why did people believe this? • What caused some to not believe this? • What is it about people that causes someone to reject popular thoughts? • Is this behavior good or bad for society?

4. Using A Scientific Approach The Learning Objectives are here to identify the main concepts you are to know by the end of this lesson. The Performance Objectives are here to identify the activity you will do to ensure you know it & I can be sure you are working towards reaching a “3” on the learning scale. You accomplish mastering the learning objectives by doing the performance objectives. • Learning Objectives: • Define & describe the steps in the scientific method. • Explain the groups and variables in a controlled experiment. • Compare and contrast scientific theories and scientific laws. • Define & explain the importance of models in science. • Performance Objective: • At the end of class you will have completed a flow chart outlining the scientific method. Your job is to know all the steps of the scientific method and be able to identify these in varying scenarios as well as be able to set up an experiment that utilizes all these steps.

5. Using A Scientific Approach • Vocabulary: • Scientific method • Observation • Hypothesis • Control group • Experimental group • Dependent variable • Independent variable • Scientific theory • Scientific law • Model

6. The Scientific Method • The Scientific Method is a step-by-step approach to problem solving. • Used correctly, the scientific method can help you solve problems of all sorts, from personal to physical.

7. Make a claim Your 1st “Handout” (like I have on the board). Fill it in as we go. Refer to the back board…

8. Using A Scientific Approach • Empirical science is attributed to Aristotle, however Muslim scientists in the 10th – 14th centuries (most notably al-Haytham) were the first ones to use the basic approach to problem solving. For notes: Write down the underlined portion! • Scientific Method: • It is an organized plan for gathering, organizing, and communicating information • The goal of scientific methodology is to solve a problem or to better understand an observed event. • The strength of the method is that, if done right, the solution is highly credible as opposed to merely opinion.

9. Beginning a Scientific Investigation • The 1st Step… • Observation: is information that you obtain through your senses. • Observation is the act of noting or perceiving objects or events using the senses. • Observation takes interest and patience. • It takes care but a desire to know WHY? What the…

10. Using A Scientific Approach • Observations lead to questions. • You see lightning in a storm. • You might wonder, “What temperature is it?” • An apple hits you in the head as you sit under it. • You ponder, “Why do apples fall?” • You can’t eat raw eggs so you cook them. • You ask, “Why do eggs become solid when they are boiled?” • Soaps come in all colors. • But you notice, “Why does soap always lather white even though it comes in a bunch of other colors?” • The genes for hair are all the same. • But you ask, “Why is some hair brown and other hair red?” • You get a candy bar from the store. • You say, “Dang this chocolate's good! I wonder why?”

11. Using A Scientific Approach • Making observations leads to questions. • The 2nd Step… • Form a Hypothesis: • A hypothesisis a possible answer to a question that CAN BE SCIENTIFICALLY TESTED! • In other words, A hypothesis is a prediction that can be tested by observation or experimentation. • A hypothesis is NOT JUST AN EDUCATED GUESS! • It is useful to make create a hypothesis as an ‘if… then… because…’ statement.

12. Scientific Method: Hypothesis • Hypothesis examples… • Which is best? • Chocolate is sweet b/c of sugar. • Candy is sweet because it makes me happy. • If I take sugar out of a chocolate recipe then the resulting candy will not be as good because sugar makes the chocolate good.

13. Examine the Hypothesis • What are parts of a good hypothesis?… • If I take sugar out of a chocolate recipe then the resulting candy will not be as good because sugar makes the chocolate good. Some thing that’s tested Compared to something that’s known The prediction The measurable outcome

14. Using A Scientific Approach • The 3rd Step… • Design & Conduct a Controlled Experiment: • A controlled experiment is one that is designed so that only one variable is changed at a time. • What is a variable? • It’s a factor or value that can change or has multiple values. • Experiments come in all shapes & sizes: • Trials, taste tests, competitions, simulations,

15. Using A Scientific Approach • Good Experiments have TWO Groups • Group #1 • Control Group: • This group has expected results • This group is the predictable standard • Ex. Chocolate candy bar made from the original recipe…you know how the chocolate is going to taste.

16. Using A Scientific Approach • Group #2 • Experimental Group: • This group has the ONE and only ONE variable changed (related to the hypothesis) to cause a measurable change different from the control group. • Ex. Chocolate that has been made w/out sugar…you aren’t really sure how the chocolate is going to taste but you’re pretty sure

17. Controls • A CONTROL can be challenging to figure out. • The thing to remember about controls is that they need to exist for comparison purposes. • If your experiment is testing one thing changing, like the chocolate recipe, this is easy to decide. • When you are comparing several unknowns, this can be a little more difficult to decide…

18. The Variables • The thing that is being tested in an experiment is called the independent variable. • This is sometimes called the manipulated variable. • A special aspect of the scientific method is that one controlled experiment has only 1 independent variable. • Remember, the independent variable is the ONE thing being tested in an experiment.

19. Using A Scientific Approach • On experimentation variables… • Experiments have variables. • Independent Variables (aka manipulated variables) are changes that are directly caused by the experimenter (you.) • Ex. Amount of sugar added to candy • This is the thing that is stated in the hypothesis. • It will generate data = dependent variables. • Dependent Variables (aka responding variables) are changes that occur due to independent variables. • These are the values that can be measured! • Ex. Candy is not as good b/c of lack of sugar

20. Identify The Control • Hypothesis: If I feed a fish four times a day it will grow bigger than a fish fed twice a day because food causes organisms to grow. • Experiment: One tank of gold fish is fed the normal amount of food once a day, a second tank is fed twice a day, and a third tank four times a day during a six week study. The fish’s weight is recorded daily. • What is the control? • The fish that’s fed once a day. • Why? This is the baseline measurement. Everything else compared to this would be a change. • What would be the independent & dependent variables?

21. Identify Control Group Both Watered normally Same Soil Same Sunlight Weed Killer Added This is the only thing different Hypothesis: If we use broadleaf weed killer, then the dandelions will die. • Experimental Control: • You have two flower beds that are exactly the same, they both contain the same type of dandelion, a broadleaf weed. • The bed on the left is watered everyday. • The bed on the right is watered everyday and sprayed with weed killer everyday. • This is the one thing that’s changed. • Eventually the dandelion in the bed on the right dies. • Which bed of flowers is the control group? 1 minute with partner.

22. Using A Scientific Approach • The Payoff For Having 2 Groups • The essential part of good scientific investigation lies in the comparison between the 2 groups. • The differences between the two gives data that is used to defend claims. Control Group Experimental Group Compare

23. Control Group Experimental Group Compare Expected Results Experimental Results The difference between the two = evidence that is used to defend claims!

24. Identify Control Group Both Watered normally Same Soil Same Sunlight Weed Killer Added This is the only thing different Hypothesis: If we use broadleaf weed killer, then the dandelions will die. • Experimental Control: • Why this becomes a good experiment is because there is only 1 variable changed, the weed killer.

25. Which is the Control,Which is the Experimental? Kisses Batch #1, Normal Kisses Batch #2, No Sugar 1 minute with partner What is the Independent Variable?What will be the Dependent Variable? What difference do we hope to get?

26. Using A Scientific Approach • What would be a good test for my chocolate hypothesis? • In this case we could make a few batches of chocolate and have people taste test it.

27. Using A Scientific Approach • The 4th Step: • Data is created & analyzed to draw conclusions. • You will need to take a look at data to make a decision on what it tells you.

28. Using A Scientific Approach • Gathering Data • In the case of all experiments, the most important step is to gather reliable data. • Data is any information from your experiment that you collect. • Can be numbers or polls or other. • Quantitative = Numbers • Qualitative = Descriptions

29. Data • There are several aspect of data that must be taken into account: • It must be accurate & precise as possible. • There must be enough data. (“In Triplicate”) • In this example, there will be 3 trials ran. • It must not be biased. • = shouldn’t be employed or paid by Hershey • It must be neat.

30. Using A Scientific Approach • What does the data tell you? • For our example with the chocolate we will gather tables of the preference between the control and experimental groups. • If we have taken enough reliable, accurate, unbiased data then we should be able to make a decision.

31. Poll opinion # Votes Which chocolate is sweeter Chocolate A B A B A B Trial 1 2 3 Chocolate Taste TestsDecision: does our data support our hypothesis? • If I take sugar out of a chocolate recipe then the resulting candy will not be as good because sugar makes the chocolate good. A = Sugar B = No Sugar

32. Using A Scientific Approach • Drawing Conclusions: • When drawing a conclusion we must consider the hypothesis. What was the hypothesis? • If I remove Sugar from a recipe then it will not be as good. • If your conclusion supports the hypothesis then you have performed one good experiment. • You could compare with similar tests, run another test, or repeat the same test over to be sure. • If you conclusions do not support the hypothesis then you must revise your experiment and test a new variable. • How would this happen? • Maybe cocoa actually is the sweetening agent.

33. Using A Scientific Approach • Usually one experiment isn’t enough to draw a definitive conclusion so multiple trials should be ran with the same experiment. • In our case we should run several trials, repeating the experiment exactly with different polls. • The data should be illustrated in a graph to help interpret the results.

34. BREAK DOWN THE STEPS…

37. What are the two groups in the experiment? Control Group Predictable standard = the group where you expect the results! Experimental Group Exactly the same as the control group except for one thing…the independent variable.

38. You measure the dependent variables in the experiment.

39. What Could Happen: Option 1: the data doesn’t support the hypothesis.

40. What Could Happen: Option 1: the data does support the hypothesis.

41. After the Conclusion • The Last Step… options here. • After validating a hypothesis several times you can come to a conclusion. • This is also called “making a claim”. • In our case we could claim that sugar makes chocolate sweet. • But one study usually isn’t enough. • A good scientist will retest multiple times testing a variety of similar hypotheses.

42. Make A Claim

43. Developing a Theory: • After validating many similar hypotheses you then come up with a theory that explains the result of your experiments. • A scientific theory is a well tested explanation for a set of observations or experimental results.

44. Make a claim

45. Scientific Theories • One drawback to theories is that scientific theories are never completely proven. • Ex: The theory of relativity • Ex: The theory of evolution • Ex: The theory that chocolate is the best candy on Earth.

46. Using A Scientific Approach • Scientific laws • Scientific laws are patterns in nature that don’t need to be proven. • summarizes an observed pattern found in nature without needing to explain it anymore (it’s a constant – like death and taxes). The explanation of such a pattern is provided by many scientific theories. • Law of Gravity - Newton • Law of Thermodynamics - Hess • Law of Electricity - Ohm • Conservation of mass - Lavoisier

47. CheckPoint Describe what the difference is between scientific hypotheses, theories, & laws. • Hypotheses are narrow • They are reasonable predictions to answer questions for observed singular events • Theory is a well tested explanation for patterns observed in nature based upon many related hypotheses. • Theory of evolution = change happens over time • A law describes patterns in nature • A law doesn't need testing or validation anymore • The law of gravity.

48. ScientificModels • After you prove a law, make a claim, or develop a theory, you should make a model to represent the concept. • What is a Model? • Scientific models are physical or mental representation of an object or an event • What is the Purpose of a Scientific Model? • Models make it easier to understand things that are very complex, very large, very small or difficult to observe directly. • By illustrating the theory/law/phenomenon in 2- or 3-D

49. Make a claim Model

50. Scientific Models • Example: When designing a new airplane the designer will often make a computer model demonstrating how the airplane should handle air current. • What would be a model for: • The solar system? • The earth’s rotation? • Water cycle? • An atom? • Macroeconomics? Just kidding….