#4 What should you wear to protect your clothes when in lab? What should you wear to protect your eyes in lab? If something breaks what is the FIRST thing you should do? How should girls wear their hair in lab? How should your lab station ALWAYS look? Answers: (1 pt each) Lab coat/apron Safety goggles TELL THE TEACHER! Tied back Neat and organized

https://www.youtube.com/watch?v=roCQ0WE6zbs&scrlybrkr=cb0dc660 1

Nature of Science “Science is a particular way of knowing about the world. In science, explanations are limited to those based on observations and experiments that can be substantiated by other scientists. Explanation that cannot be based on empirical evidence are not part of science.” The National Academy of Sciences 2

Nature of Science Science is based on experimentation The development of an experiment tends to follow the Scientific Method Ask a question Conduct background research Construct a hypothesis Test your hypothesis in an experiment Analyze Data Draw conclusions and communicate them 3

1. Ask a question – often based on observations Observation: Description of something you can see, smell, touch, taste, hear NOT an opinion!! (must be objective) Example: The ground is wet Inference: A guess about an object or outcome based on your observations You can make many inferences from a single observation Example: It rained. Someone was watering the plants 4

Practice: Make observations and inferences about the picture. 5

Ask a question – observations are either… Qualitative Observation: describes qualities Examples: Green liquid Large hole Sour taste Sweet smell Quantitative Observation: uses numbers to measure something Examples: 4 feet long 6 legs 7.2 grams 100 mL 6

Practice: Make qualitative observations, quantitative observations, and inferences about the picture. 7

Considerations for Quantitative Data Quantitative data must be… PRECISE = how close your measurements are to each other (think consistent or specific) ACCURATE = how close your measurement is to the correct/accepted value (think correct) Always give the most specific reading on your instrument, then estimate one more decimal place 8

Precise but not Accurate Precise and Accurate Precise but not Accurate Practice: Label the different bulls-eyes. Accurate but not Precise Not Accurate or Precise 9

Exit Ticket Draw a picture of a target with shots that are both Precise and Accurate.

Use the pictures below to answer the following questions. #1 Use the pictures below to answer the following questions. List two qualitative observations. List one quantitative observation. List two inferences. Answers: (point values in parentheses) The cookies are not circles. The girl has blonde hair. (2) There are 22 cookies in the pictures. (1) She took bites out of all of the cookies. The cookies are red velvet. (2)

1. Vocabulary word a. Short & Sweet Definition (Not glossary definition) b. Simple Picture c. Use it in a sentence or Simile Can be another tense of the word. Underline word. OR _________ b/c ____________.(justify)

1. Observation a. Short & Sweet Definition Description of something using senses b. Simple Picture c. Use it in a sentence or Simile I observed that the ground was wet. OR Statement b/c they both involve facts.

Vocabulary Cards 1. Observation 2. Inference 3. Qualitative 4. Quantitate 5. Precision 6. Accuracy Vocabulary Cards

#5 Answer TRUE or FALSE for the following 5 statements. Safety goggles must be worn at all times while working in the laboratory, even when cleaning up after an experiment. The fire blanket should be used to smother chemicals that have caught fire. Hot plates should be turned off whenever not in use, unless they are going to be used again in a minute or two. It is occasionally permissible to taste substances in the lab to determine their identity. The teacher should be notified of all chemical spills, unless they are very minor. Answers: (1 pt each) True False – always turn off when you are walking away or not using!! False – never eat ANYTHING unless I tell you you can! False – tell me of EVERY chemical spill.

2. Conduct background research – define a Purpose/Objective The GOAL of scientific investigations is to answer a question Observations  Questions  Research (what has already been found?)  Purpose Purpose/Objective is a statement that clearly shows what question you are trying to answer in your investigation 10

3. Construct a Hypothesis Hypothesis: A testable prediction based on observations (more than a guess!!) that describes a cause and effect relationship between variables Format for a Hypothesis: “IF (IV) then (DV) “ IV = Independent variable = Cause DV = Dependent variable = Effect 11

Defining Independent and Dependent Variables Independent Variable: (IV) what the experimenter will deliberately change or manipulate in the investigation The X-Axis on a graph It is the ONLY thing different between different experimental groups Ex. You want to do an experiment to see if what you drink before a race affects how quickly you run. What is the IV? 12

Defining Independent and Dependent Variables Dependent Variable: (DV) what changes in response to the independent variable The Y-Axis on a graph Usually represented by the data you collect in an investigation; what is measured Ex. Recall the running experiment. What is the DV? 13

Individual Practice Get out p 8: Understanding Hypothesis Homework if not finished Work on Vocab cards when finished.

1. Observation a. Short & Sweet Definition Description of something using senses b. Simple Picture c. Use it in a sentence or Simile I observed that the ground was wet. OR Statement b/c they both involve facts.

Exit Ticket Which variable does the experimenter change in a scientific investigation?

#6 What is the best glassware for performing small chemical reactions? What is the best glassware for measuring? What is a petri dish used for? In a graduated cylinder, what is the bottom of the curve in the liquid called that you are supposed to measure to? What type of shoes are best to wear during lab? Answers: (1 pt each) Test tube Graduated cylinder Growing bacteria cultures Meniscus Close toed shoes

4. Test your hypothesis in an experiment- Materials What will you need to conduct the experiment? Include amounts Include brands, if important Be as specific as possible! Write as a bulleted list 14

Test your hypothesis in an experiment- Procedures Write out every step that was taken Start with an action word Include every step so that someone could replicate the experiment Make this a numbered list When designing experimental procedures you must ALWAYS consider… Experimental Group: groups that are being tested What is the experimental group in the running example? 15

When designing experimental procedures you must ALWAYS consider… Control Group: group used for comparison with your experimental groups. This is the “normal” group What is the control group in the running example? Constants: the aspects of an experiment that are held constant/consistent Ensures that all aspects of trials are identical, except for the IV Ensures that any difference measured in the DV is caused only by the IV Ex. All runners should be the same age, gender, same breakfast, same training, same shoes, etc. 16

When designing experimental procedures you must ALWAYS consider… Repeated Trials to: Ensure the results aren’t due to chance Eliminate any errors Ensure the data is precise 17

Individual Practice Get out p 9: Understanding Hypothesis Homework if not finished Work on Vocab cards when finished.

Exit Ticket Something that stays the same between experimental groups and control groups is called a ________.

#7 1. What is the independent variable in the hypothesis below? If a student attends afterschool tutoring, then they will score higher on their test than students who do not attend tutoring. 2. What is the dependent variable in the hypothesis above? 3. Write a hypothesis using these IV and DV IV = Different amounts of fertilizer DV = Plant growth Answers: Whether or not they attend tutoring/amount of tutoring (1) Test scores (1) If the amount of fertilizer increases, then the plant growth will increase. (3) Answers will vary. Grade on proper format.

Exit Ticket Why is it important to have constants between groups in today’s experiment?

#8 I want to design an experiment to see if drinking coffee makes students score higher on tests. What is the independent variable in this experiment? What is the dependent variable in this experiment? What would be the control group in this experiment? 4. What would be the experimental group in this experiment? 5. List a necessary constant. Answers: (1 pt each) Amount of coffee Test Score No coffee or water (answer may vary, as long as it is something normal to be used for comparison) Different amounts of coffee Same test, same age of students, same type of coffee, etc. Answers will vary.

5. Analyze Data – Results and Analysis Results Collect data in an organized form during an investigation (ex. Data Table) Present data in a graph Analysis Only make statements about what the data shows Do NOT state in analysis whether your hypothesis was “right” or “wrong” Include any errors you made

6. Draw conclusions and communicate them Make an explicit statement about whether your hypothesis was supported or rejected by your experimental data Data may support your prediction Data may fail to support (reject) your prediction NOTE: Data does NOT prove/disprove State the real world application.

Individual Practice Get out p 12, 13: Product Control Group Experimental group Difference

On which axis do you plot the independent variable? Exit Ticket On which axis do you plot the independent variable?