2. The Scientific Method∗ What is the scientific method? ∗ It is a process that is used to find answers to questions about the world around us.
3. ∗ Is there only one “scientific method”? ∗ No, there are several versions of the scientific method. ∗ Some versions have more steps, while others may have only a few. ∗ However, they all begin with the identification of a problem or a question to be answered based on observations of the world around us.
4. ∗ They provide an organized method for conducting and analyzing an experiment.
5. ∗ What is a hypothesis? ∗ It is an educated guess based on observations and your knowledge of the topic. ∗ You state it as a possible answer to a question.
6. ∗ Stated in the “If….., then….” format∗ Example: IF I water three plants with different sodas, THEN the plant that receives Sprite will grow the tallest.
7. ∗ What is data? ∗ It is information gathered during an experiment. ∗ It is organized into a data table and displayed visually as a graph.
8. Graphs∗ BAR GRAPHS: can be used to show how something changes over time or to compare items. ∗ have an x-axis (horizontal) and a y-axis (vertical) ∗ the x-axis has time period or what is being measured ∗ the y-axis has numbers for the amount of stuff being measured. ∗ good when youre plotting data that spans many years (or days, weeks...), has really big changes from year to year (or day to day...), or when you are comparing things.
9. ∗ LINE GRAPHS: can be used to show how something changes over time∗ x-axis has numbers for the time period∗ y-axis has numbers for what is being measured.∗ can be used when youre plotting data that has peaks (ups) and valleys (downs), or that was collected in a short time period.∗ Used for two sets of numerical data (ex: time and temp)
10. Steps of the Scientific Method∗ 1. Choose a problem: State the problem as a question.∗ 2. Research your problem: Read, get advice, and make observations.∗ 3. Develop a hypothesis: Make a prediction about what will happen.∗ 4. Design an experiment: Plan how you will test your hypothesis.
11. ∗ 5. Test your hypothesis: Conduct the experiment and record the data.∗ 6. Organize your data: Create a chart or graph of your data.∗ 7. Draw conclusions: Analyze your data and summarize your findings.
13. 3 Kinds of Variables∗ Independent Variable – something that is changed by the scientist ∗ What is tested ∗ What is manipulated (changed)
14. ∗ Dependent Variable – something that might be affected by the change in the independent variable ∗ What is observed ∗ What is measured ∗ The data collected during the investigation ∗ “the numbers” ∗ Example: how tall the plant grew, how far the paper airplane flew
16. ∗ Controlled Variable – a variable that is not changed ∗ Also called CONSTANTS ∗Allow for a “fair test” ∗ Everything in the experiment except for the IV should be kept constant
17. Procedure∗ Give a detailed explanation of how you will conduct the experiment to test your hypothesis∗ Be clear about the variables (elements you change) versus your constants (elements that do not change)∗ A control is the group that you use as a comparison to see if change has occurred. ∗ Example: In a medicine study, the group of people who don’t get the medicine are the control group
18. ∗ Be very specific about how you will measure results to prove or disprove your hypothesis. You should include a regular timetable for measuring results or observing the projects (such as every hour, every day, every week)
19. Conclusion∗ Conclusion: your results or findings based on data collected during the experiment∗ Answer your problem/purpose statement∗ What does it all add up to? What is the value of your project?∗ What further study do you recommend given the results of your experiment? What would be the next question to ask?∗ If you repeat this project, what would you change?
20. For Example:Students of different ages weregiven a jigsaw puzzle to puttogether. The scientist wanted tosee if the students’ ages affectedhow long it took to put the puzzletogether.
21. Identify the Variables in this Experiment:∗ Independent Variable (IV): ∗ Ages of the students ∗ Different ages were tested by the scientist∗ Dependent Variable (DV): ∗ The time it took to put the puzzle together ∗ The time was observed and measured by the scientist
22. What were the constants?∗ (1) Same puzzle ∗ All of the participants were tested with the same puzzle. ∗ It would not have been a fair test if some had an easy 30 piece puzzle and some had a harder 500 piece puzzle.∗ Other constants: (2) same location, (3) same stopwatch, (4) same person timing the experiment
23. Another Example:∗ 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.
24. What are the Variables?∗ IV: Sizes of nails ∗ These were changed by the scientist∗DV: Number of paper clips picked up ∗ The number of paper clips observed and counted (measured)∗ Constants: Battery, wire, type of nail ∗ None of these items were changed
25. Let’s Practice!∗ If I use a heavier bowling ball, then the ball will travel faster down the lane.∗ IV: weight of bowling ball∗ DV: speed it traveled down lane
26. ∗ 2) If I use different brands of paper towels, then Bounty will absorb more water per minute than Sparkle or Quilted.∗ IV: brand of paper towel∗ DV: amount of water absorbed per minute
27. ∗ 3) If I put 3 spider plants in different locations, then the plant in the sunlight will grow taller in a one-week period than the plants in the closet and basement.∗ IV: location of the plants∗ DV: height of plants