SCIENTIFIC METHOD

1. SCIENTIFIC METHOD A Way to Solve a Problem

2. Day 1 Write in your agenda: I can ask questions and form hypotheses that can be explored through scientific investigations.

3. Activator: In your agenda write a sentence or two explaining what you think this picture represents.

4. Vocabulary • Inquiry: an investigation; the testing of an idea in a search for knowledge • Observation: What you actually saw happen during an experiment. • Inference: logical conclusion drawn from available evidence and prior knowledge; inferences are often made from observations and attempt to explain what we see.

5. Examples of observation • The balloon on the bottle containing Nutrasweet did not expand. • The plant that received SuperGro fertilizer grew 4 cm. in the first week. • The ducks fed in the shallow end of the pond 85% of the time.

6. Examples of Other Laboratory Related CRCT Questions • The students in Mrs. Padgett’s class wanted to learn about the ducks in a pond near the old middle school. Which question could the class answer by making observations at the pond? • Where do the ducks go when they migrate? • Which part of the pond do the ducks use for feeding? • How many ducks were in the pond last May? • How many years have certain pairs of ducks been together?

7. Examples of inference • When Jordan studies for a test, she always gets an A (this represents what you already know about Jordan.) On the last test, Jordan scored a 70 (This is what you observe at this time.) What inference can you make? • Jordan did not study

8. Examples of inference The geological boundary known as the “Fall Line” in Georgia is believed to be the area where the ancient coastline existed. What types of scientific data might have first led scientists in the 1800s to infer that the ocean at one time covered half of Georgia? A. Ancient writings found on stone tablets dating over a million years old. B. An abundance of fossil remains of ancient sea-dwelling creatures like clams that are found far from the modern day coastline. C. The remains of ancient boats estimated to be 200,000 years old that were preserved in mud near Macon. D. Photographs taken by aliens who are capable of traveling back in time.

9. A lab report for a plant experiment contained the four statements below. Identify whether the statement is an observation, hypothesis, or inference. • All of the plants bent toward the small light source. • observation • 2. Each of the plants grew less than 2 cm. • observation • 3. Lack of light caused the plants to grow at a slower rate. • inference • 4. Several of the plants have yellow leaves. • observation

10. What is the Scientific Method? • It is a series of steps a scientist takes to identify a question, develop a hypothesis, design/carry out the procedures to test the hypothesis, and document observations and report findings.

11. In other words, it’s a way to solve a problem.

12. Steps for the Scientific Method • Step 1 State the problem • Step 2 Gather information Observations can be made in many different settings: a. lab investigations b. computer models c. fieldwork

13. 3. Form a hypothesis, or a prediction that can be tested. It is an educated guess. Your hypothesis should be based on research. You should always be able to give reasons why you chose your hypothesis.

14. Examples of a Hypothesis • Yeast will not feed on sugar substitute. • Tomato plants that receive MegaGro fertilizer will produce larger fruit. • The Energizer brand battery will last longer than Duracell in devices like digital cameras.

15. Example from OAS • Which is a hypothesis? • Five earthworms died when the soil became too dry. • Earthworms have a mucous covered outer surface. • Heavy rain causes earthworms to move above the ground. • What will happen if an earthworm is cut in two? • Lettersa and b are observations. D is a question. • C is a hypothesis

16. Example from OAS Euglena are single-celled organisms. The flagellum helps the organism move through water. Euglena are similar to plants in the way they obtain their food. Nina kept several euglena in a glass jar. She wondered what would happen if she covered the top half of the jar with black paper and placed it in sunlight. Which is the best prediction of how the euglena will respond to the change in the jar environment? A. Most of the euglena will move to the bottom half of the jar. B. Most of the euglena will move to the top half of the jar. C. The euglena will spread out evenly throughout the jar. D. The euglena will move back and forth between both halves.

17. Day 2 Write in your agenda: I can ask questions and form hypotheses that can be explored through scientific investigations.

18. Activator: Have the students close their eyes and slowly read the three sample observations

19. 4.Test the hypothesis w/ an experiment a. A Variable is something in an experiment that can change. b. A control is the standard of comparison in an experiment; it cannot change

20. Experiments contain variables. For example, in the following experiment Jose wants to determine how water temperature affects the rate at which yeast breaks down sugar to make bread dough rise: The amount of water, water temperature, yeast, sugar, and flour are all variables. Which variable is the only variable that changes in each trial? _______

21. Independent Variable • Independent Variable – something that is changed by the scientist • What is tested • What is manipulated • The one and only variable you will change during an experiment.

22. Constants The other variables do not change. They are constants. The constants in an experiment are all the factors that the experimenter attempts to keep the same.

23. If more than one variable changes, the trials will not be reliable. What is wrong with the variables for this experiment measuring the effect of different colored lights on plant growth? The dependent variable is part of the results. In the trials above measuring the effects of water temperature on the rate at which yeast breaks down sugar, the dependent variable would be the size of the bread dough after it had risen.

24. Dependent Variable • Dependent Variable – It is what you measure to compare the results of your tests. • It is the data collected during the investigation. • It should be able to be charted or graphed.

25. Control • It is what you will compare your results to; usually just the absence of the independent variable. • The control group is exposed to the same conditions as the experimental group, except for the variable being tested. • All experiments should have a control group. Allow for a “fair test” . • In the experiment mentioned on the previous slide to observe the effects of different colored lights on plant growth, the control would have all the same variables but the light source would be a normal full spectrum growing light that produces light similar to that of the sun.

26. Jody wants to conduct an experiment to see if • adding salt to water will make water boil faster. What is the independent variable in this experiment? The amount of salt used.

27. Archibald wants to conduct an experiment to determine which of his three candles burns the longest. One is made of beeswax, another soy wax, and the third paraffin wax. Each candle has a tapered shape, is 8 inches in height, and weighs 6 ounces. What is the independent variable in this experiment? The type of wax.

28. What is the independent variable in this experiment? The amount of light each sample was exposed to. What inference can you make from the data in this table? Light was not necessary for a seed to germinate.

29. Identify the variables in this investigation.

30. Students of different ages were given the same jigsaw puzzle to put together. They were timed to see how long it took to finish the puzzle.

31. What was the independent variable? • Ages of the students • Different ages were tested by the scientist

32. What was the dependent variable? • The time it to put the puzzle together • The time was observed and measured by the scientist What was the Constant? • The puzzle

33. An investigation was done with an electromagnetic system made from a battery and wire wrapped around a nail. Different sizes of nails were used. The number of paper clips the electromagnet could pick up was measured.

34. Independent Variable: • Sizes of nails • These were changed by the scientist

35. Dependent Variable: Number of paper clips the magnet could pick up. Constant: Battery, wire

36. Intentionally manipulated Controlled Cause Intentionally left alone Measured Effect Independent V. Dependent

37. 5. Make observations and collect data 6. Draw conclusions a. hypothesis supported = repeat experiment b. hypothesis not supported= revise hypothesis

38. 7. Share your results

39. Think you can name all seven steps?

40. Scientific Method Steps • State the problem • Conduct research • Form a hypothesis • Test your hypothesis • Make observations and collect data • Draw conclusions from your data • Share your results

41. Do you know the difference between the independent and dependent variables?

42. Independent Variable The independent, or manipulated variable, is a factor that’s intentionally varied by the experimenter.

43. Dependent Variable The dependent, or responding variable, is the factor that may change as a result of changes made in the independent variable.