1. LAB EQUIPMENT, WHMIS AND THE SCIENTIFIC METHOD 5 entry sheet

2. WHAT DO YOU THINK THE GENERAL RULES AND PROCEDURES FOR HANDLING EQUIPMENT SHOULD BE? 2

3. THE SCIENTIFIC METHOD WHAT IS IT, AND WHY DOES IT MATTER?

4. WHAT IS A PURPOSE WITHIN THE FRAMEWORK OF THE SCIENTIFIC METHOD? *The purpose is the reason you are doing an experiment* -A purpose must be specific. -A purpose is generally written as a statement. You are outlining your intention. Ex. To determine the effects of soil pH on plant growth. - The purpose can also be posed as a question: Ex. How will the density of the liquid affect the buoyancy of the ball? 1

5. Definition: The purpose is the goal of the experiment Important points regarding the purpose: - Must be specific - Can be a statement - Can be a question 4

6. CREATING A PURPOSE Working individually, come up with a purpose for experiments involving the following parameters: -Wind speed and energy produced -Salt and the time needed for a cube of ice to melt -Surface area and dissolving sugar cubes -Wing span and wind glider flight distance 6

7. VARIABLES Variables are those factors in an experiment that impact the observed results. The independent variable is the variable that the experimenter is changing (intentional). The dependent variable is the variable that is being measured – it is DEPENDENT on the INDEPENDENT variable. Controlled variables are those that are not changed. 8

8. EXAMPLES Situation: We are trying to determine the effect of differing wing sizes on glider flight distances: Independent Variable: The wing size of each glider model is the independent variable. Dependent Variable: Flight distance is the observed/measured variable. Control Variable(s): The glider body model is a controlled variable. 2

9. IDENTIFYING VARIABLES Working individually, complete the assigned work sheet ****Please cross out question 4**** 18

10. THE HYPOTHESIS For the purposes of experimentation, a hypothesis is best stated as an educated opinion/prediction. When we form a hypothesis, we are both stating the intent of our experiment and predicting the final outcome. When you write a hypothesis, be sure to avoid such language as “I think,” “in my opinion,” or “I would guess.” Effective hypotheses are not written as guesses, but as confident predictions based on prior knowledge. The experiment will determine whether or not our ideas are to be disproven. 2

11. Hypothesis: important points Do not say “I think” or “I guess.” A hypothesis must include the intent of the experiment, and a prediction of the final results. Definition: A proposed explanation made on the basis of limited evidence as a starting point for further investigation. 8

12. A good way to start writing hypotheses is to use the form “If… then… because…” Also, all hypotheses must identify the independent variable, dependent variable, and expected outcome. If the wings are larger, then the plane will fly further because there will be more lift generated. The powdered sugar will dissolve the fastest because it has the largest surface area. *Please take note of the language used. The sentences convey confidence. We are not guessing – we are predicting.* EXAMPLES 1-2

13. FORMING HYPOTHESES Working individually, form hypotheses for each of the below statements. If possible, your work will be submitted at the end of the period. Incomplete work will be due on Friday: 1: Does heat impact yeast growth? 2: What is the link between fast food consumption and unhealthy skin? 3: How quickly can lizards move in different temperatures? 10

14. TOMORROW … Fair Tests and control experiments/trials Analyzing results Conclusions WHMIS 3

15. FAIR TESTS AND CONTROLS For an experiment to generate accurate results, it must be a fair test. For a test to be considered fair, only one variable can be altered. If two or more variables are changing, then we can not possibly predict which of the changes is producing our observed results. Fair tests also make use of positive and negative controls. Positive controls must always yield an expected result, while negative controls must yield no result. Our controls ensure us that our experimental design is not flawed, and that our equipment is functioning as it should. 4

16. Fair Tests: Can only have 1 independent variable Must have a positive and negative control

17. IS IT FAIR? 1: An engineer is conducting an experiment on the load-bearing capacity of a new shelf design. She determines that she will change both the height of the shelf and construction material used (wood, iron, steel, etc.) after each experiment. Is this a fair test? 3

18. 2: A team of researchers are trying to determine the impact of steroidal medication injections on pregnant mice. The researchers decide that 40 mice will be tested. 5 of the mice will receive innocuous water injections that should yield no results. In addition, 5 other mice are to be given a commercial steroidal injection known to produce infant mortality in pregnant mice. The remaining 30 will form the sample group. The team has established that they will be testing the impacts of altering dosage – the injection type will not be altered.

19. ANALYZING RESULTS After successfully completing the experiment, our next step is to organize and analyze our data. This step often involves the generation of graphs, calculations, conversions, etc. Tips: Always keep your purpose in mind. Track your data in an organized and easy to follow manner. Attempt to interpret your data in light of peer-reviewed research and prior knowledge. 2

20. THE CONCLUSION A conclusion should be concise, should restate the purpose, and should outline all significant data and results. A conclusion should include your rationale – based on your results – for either accepting or refuting your hypothesis. Do not use firm language. Always use language such as “we can tentatively conclude,” or “the data suggests.” No hypothesis is ever absolutely confirmed. 2

21. Write a conclusion for the experiments described/demonstrated in the video(s) 7

22. WRITING A CONCLUSION 1

23. 1

24. FROM HYPOTHESIS TO CONCLUSION As you watch the following video, state the purpose, identify the independent/dependent/control variables, form a hypothesis, and present a conclusion. Your work will be submitted at the end of the period. 10 GOOD LUCK!

25. Purpose: Independe nt variable: Dependent variable: Controlled variable(s): Hypothesis: Conclusion:

26. WHMIS

27. Working in your assigned groups of 5, determine what each of the labels indicates. You may use your cell phones for this activity. Each member of your group must record this information in their notes. 10

28. WHMIS QUIZ A – Compressed gas B – Flammable and combustible material C – Oxidizing material D1 - Materials causing immediate and serious toxic effects D2 - Materials causing other toxic effects D3 – Bio-hazardous Infectious material E – Corrosive material F – Dangerously reactive material 5