Scientific Method PDF

Alaa Y. El-Daly Assistant Lecturer – English Department sinaiuniversity.net Scientific Method The scientific method is a form of critical thinking that reduces the degree of uncertainty. The scientific method is used in all sciences—including chemistry, physics, geology, and psychology. The scienti...

Alaa Y. El-Daly Assistant Lecturer – English Department sinaiuniversity.net Scientific Method The scientific method is a form of critical thinking that reduces the degree of uncertainty. The scientific method is used in all sciences—including chemistry, physics, geology, and psychology. The scientists in these fields ask different questions and perform different tests. However, they use the same core approach to find answers that are logical and supported by evidence. @Sinaiunieg [email protected] www.su.edu.eg Scientific Method The scientific method is critical to the development of scientific theories, which explain empirical (experiential) laws in a scientifically rational manner. In other words, it is the technique used in the construction and testing of a scientific hypothesis. @Sinaiunieg [email protected] www.su.edu.eg Scientific Method The scientific method includes 5 basic “steps” : 1. Observation 2. Question 3. Hypothesis 4. Experiment 5. Evaluation @Sinaiunieg [email protected] www.su.edu.eg The scientific first process method in the involves the observation. The scientific method starts when you ask a question about something that you observe: How, What, When, 1. Observation Who, Which, Why, or Where? @Sinaiunieg [email protected] www.su.edu.eg Scientific Thinking Observation A B The grass in picture A is taller than the grass in picture B Observation leads to a question that needs to be answered. Scientific questions need to be answerable. 2. Question @Sinaiunieg [email protected] www.su.edu.eg Scientific Thinking Questioning A B Why The grass in picture A is taller than the grass in picture B? To answer a question, a hypothesis will be formed. This is an educated guess. A scientific hypothesis has to be testable and also has to be falsifiable. A hypothesis must exclude 3. Hypothesis supernatural explanations. @Sinaiunieg [email protected] www.su.edu.eg Scientific Thinking Forming a Hypothesis specific A hypothesis has to be: testable falsifiable A hypothesis is usually written in the form of an if/then statement. This statement gives a possibility (if) and explains what may happen because of the possibility (then). The statement could also include "may." Scientific Thinking Forming a Hypothesis What are the things that affect plant growth? A • May be plant B receives Less sun than plant A. • May be plant A receives more water. • May be the soil quality in plant A is better than plant B. • May be plant B is mowed and plant A is not. B Once the hypothesis has been Scientific Method established, it is time to test it. The process of experimentation is what sets science apart from other disciplines. @Sinaiunieg 4. Experiment [email protected] www.su.edu.eg Scientific Thinking Experimenting A B How does water affect plant growth? All evidence and conclusions must be analyzed to make sure bias or inadequate effort did not lead to incorrect conclusions. 5. Evaluation @Sinaiunieg [email protected] www.su.edu.eg Variables Scientific Method Ex. If you were measuring the growth rate of trees receiving fertilizer applications compared to the growth rate of trees receiving no fertilizer applications, what would be the variables? @Sinaiunieg [email protected] Variables www.su.edu.eg Variables Ex. Scientific Method Independent variable.= controlled variable  Fertilizer application Dependent variable= responding variable  Tree growth rate @Sinaiunieg [email protected] Variables www.su.edu.eg Variables Ex. The variable deliberately changed in an experiment is known as the independent variable. Scientific Method The dependent variable is the variable that may change as a result of changes in the independent variable. In most experiments, one variable is independent, one is dependent, and all others are controlled. @Sinaiunieg [email protected] Variables www.su.edu.eg Variables Ex. Scientific Method • Independent manipulated. variables are • Dependent variables are observed and measured. • Constants are conditions that are kept the same. @Sinaiunieg [email protected] Variables www.su.edu.eg Scientific Thinking Forming a Hypothesis What are the things that affect plant growth? Variables A B Scientific Thinking Forming a Hypothesis What are the things that affect plant growth? an element, feature, or factor that can be changed or controlled Variables Note: You must only deal with one variable during an experiment Scientific Thinking Forming a Hypothesis Variables Independent variable: The thing that you change in order to measure its effect Dependent variable: the thing to be measured (data) Scientific Thinking Forming a Hypothesis What are the things that affect plant growth? A Now lets choose one variable and come up with a question to investigate How does water affect plant growth? B Scientific Thinking Forming a Hypothesis How does water affect plant growth? A B Let’s form a hypothesis if/then If (independent variable), then (dependent variable) Scientific Thinking Forming a Hypothesis How does water affect plant growth? A B We need Let’s formaa predicted hypothesis if/then outcome If (_____water), then (___ plant growth) Specific? Testable? Falsifiable? Scientific Thinking Forming a Hypothesis How does water affect plant growth? We need a predicted outcome A B Let’s form a hypothesis if/then If (plant is watered), then (plant growth will be affected) Specific? Testable? Falsifiable? Scientific Thinking Forming a Hypothesis How does water affect plant growth? We need a predicted outcome A B Let’s form a hypothesis if/then If (plant is watered), then (plant growth will increase) Specific? Testable? Falsifiable? Scientific Thinking Forming a Hypothesis How does water affect plant growth? Let’s form a hypothesis How does studying affect test scores? If I study, then my test scores will increase. Scientific Thinking Forming a Hypothesis How does water affect plant growth? Let’s form a hypothesis How does caffeine affect our blood pressure? If I drink caffeine, then my blood pressure will increase. Scientific Thinking Forming a Hypothesis How does water affect plant growth? Let’s form a hypothesis How does caffeine affect our blood pressure? Can I say: “If I drink caffeine, then my blood pressure will decrease.”? Scientific Thinking Experimenting How does water affect plant growth? A B Hypothesis: If (plant is watered), then (plant growth will increase) Control group A controlled scientific experiment needs two groups Experimental group Scientific Thinking Experimenting Control group Experimental group The group that doesn’t receive an independent variable The group that receive an independent variable Scientific Thinking Control group Experimenting Experimental group The purpose of the control group is comparison. It doesn’t receive the independent variable so we can compare the results. But what about the other variables? Scientific Thinking Experimenting Other variables Control group Experimental group • • • • • • Species Height Soil Sunlight Temperature time constants Scientific Thinking Experimenting Other variables • Control group Experimental group • • • • • Both plants must be from the same species Both plants must have the same Height Both plants must grown at the same type of soil Both plants must receive the same amount of sunlight Both plants must kept at the same temperature Both plants must grow for the same amount of time Scientific Thinking Control group Experimenting Experimental group We analyze the data and report the result of experiment and we document every single detail about what we have done and compare the result to the control group Scientific Thinking Evaluation A Does the result support or reject our claim? B Does the result prove our claim? Scientific Thinking Evaluation Does the result prove our claim? A B Science is growing a collection of knowledge that builds on previous ideas. Although we can never truly (prove) a claim, we can repeat experiments to build stronger evidence to (support) our claims Scientific Method Match the scientific method’s components (observation – question - hypothesis – Experiment– Evaluation) to the following problem’s stages : @Sinaiunieg [email protected] www.su.edu.eg Scientific Method Missing wallet (observation – question - hypothesis – Experiment– Evaluation) I went to the market to buy some goods with my friend Mae Ann. When I reached home I noticed that my wallet was gone. ( @Sinaiunieg ) [email protected] www.su.edu.eg Scientific Method Missing wallet (observation – question - hypothesis – Experiment– Evaluation) Where did I lose it? ( @Sinaiunieg ) [email protected] www.su.edu.eg Scientific Method Missing wallet (observation – question - hypothesis – Experiment– Evaluation) I lost it in the market while we were buying goods. Mae Ann got my wallet. I had misplaced it in the house. ( @Sinaiunieg ) [email protected] www.su.edu.eg Scientific Method Missing wallet (observation – question - hypothesis – Experiment– Evaluation) I searched all over the house for my wallet, but I could not find it. Then I went to Mae Ann to ask if she got my wallet. She answered in the affirmative. She said she found it while she was on her way home near the market. ( @Sinaiunieg ) [email protected] www.su.edu.eg Scientific Method Missing wallet (observation – question - hypothesis – Experiment– Evaluation) I lost my wallet in the market and Mae Ann found it and gave it back to me. ( @Sinaiunieg ) [email protected] www.su.edu.eg I. Read the following situation then match each term with the right choice: A teacher noticed that some of his top students weren’t scoring high in tests. They were also always anxious and agitated. He guessed that the problem may have resulted from caffeine consumption. To do an experiment, he selected some of his students that suffered from that signs of that problem. He divided them into two groups; (A) and (B). Group (A) were observed as they did their routine of studying and drinking coffee. On the other hand, group (B) was following the exact same routine but they weren’t allowed to consume coffee or any caffeinated beverages. The result was that the students of group (A) scored the same bad marks and showed signs of agitation, while the students of group (B) were calmer and scored better and higher degrees in their exams. So, it was decided that all students mustn’t consume coffee or caffeinated beverages during exam times. 1. Observation b a. caffeine consumption may prevent the students from scoring well b. the students couldn’t get high marks in exams 2. Question d 3. Hypothesis c. stopping students from drinking caffeinated beverages a 4. Experiment c 5. Evaluation e d. What are the reasons that make the students get bad marks in exams? e. caffeine is indeed the main cause of doing bad in exams 1. Independent variable a. Students b 2. Dependent variable b. Caffeine e 48. Constant c. Group (A) a 49. Control group d. Group (B) d 50. Experiment group c e. Students’ marks on exams II. Read the following situation then match each term with the right choice: Cowpox is uncommon illness cattle, usually mild, that can be spread from a cow to a human via sores on the cow’s udder. Smallpox, in contrast, was deadly disease of humans. It killed about 30% of those it infected. Survivors often bore deep, pitted scares on their faces and other parts of the body affected by the blistering illness. Smallpox was a leading cause of blindness. 1.Observation a. How danger is Cowpox on humans? c 2. Question a b. If a person has been intentionally infected with cowpox, then that person will be protected from becoming ill after a purposeful exposure to smallpox. b c. Infecting a person with Cowpox protects from infection with smallpox. Jenner represented his experiment several times and got the same findings. 3. Hypothesis d. People who have had Cowpox don’t become ill with smallpox. 4. Experiment e 5. Conclusion d e. Infect a person with Cowpox. Then try to infect the person with smallpox. Choose from "a, b, c, d, or e" to match the following sentences with their correct scientific method: 1. Observation a. My coffee maker works! c 2. Hypothesis b. I plug my coffeemaker into the outlet. e c. My toaster doesn’t work. 3. Question d 4. Result d. Is something wrong with my electrical outlet? a 5. Experiment b e. If something is wrong with the outlet, my coffeemaker also won’t work when plugged into it. Read the following problem then choose the correct answer from “a, b or c”: (A) While taking some blood samples from people of a random village. We noticed that most of the residents of this village have some type of developing disease because of the kind of food or drink they have. 1. What question does this information make you ask? a. Do the blood samples cause the disease? b. What could be the cause of this disease to infect most of the residents of this specific village? c. Where does the disease develop? 2. If the samples can be tested, then the hypothesis could be___________. a. If they have good food and drink, they might not infect with this disease. b. If they have food and drink, then they might have this disease. c. If they have unclean food or water, they may not suffer from this disease. 3.The Independent variable is ___________. a. Food/drink 4.The experimental group is ___________. a. Food/drink b. residents c. disease b. residents c. blood samples Choose the correct answer from “a, b or c”: 1. A scientific ______________ has to be testable and falsifiable. a. hypothesis b. question c. conclusion 2. _______________leads to a question that needs to be answered to satisfy human curiosity. a. Evolution b. Observation c. Evaluation 3. ____________ variables are observed, measured and manipulated. a. Dependent b. Independent c. Constant 4. A/An ______________ is designed to prove or disprove the hypothesis. a. problem b. experiment c. consequence THANK YOU For any questions feel free to contact me by mail Alaa.es haq@s u.edu.eg Alaa Y. El-Daly Assistant Lecturer – English Department