1. Thinking like a Scientist

2. Science is an organized way of using evidence to learn about the natural world.
The word science also refers to the body of knowledge that scientists have built up after years of using this process.

3. What is the goal of science?
The goal of science is to:
investigate and understand the natural world.
explain events in the natural world.
use those explanations to make useful predictions.

4. Thinking Like a Scientist
Scientific thinking begins with observation.
Observation is the process of using your senses to gather information about events or processes in a careful, orderly, accurate and objective way.
Accurate: exact report of what your senses tell you
Objective: avoids opinions (or bias) based on a previously held point of view (just the facts, please)
Our 5 senses are: touch, taste, smell, hearing, sight

5. Observation vs. Opinion
Science is about facts, not opinions
Saying a dress is red is a fact
The color red is observable with your senses, red is always the same
Saying a dress is pretty is an opinion
everyone likes different types & colors of dresses so the idea of pretty is different for different people

6. The information gathered by observations or experiments is called data.
QuaNtitative data: expressed as Numbers, obtained by counting or measuring
2) Qualitative data: descriptive words (adjectives) used and involves characteristics that aren’t or can NOT
easily be counted or measured
QuaNtitative: 8 zebras are in this picture
Qualitative: most zebras are looking to the right

7. Types of Observations QuaNtitative observations–numbers involved
e.g. he is 7 feet 1 inch
Qualitative observations- words involved
e.g. he is very tall

8. Scientists use data to make inferences.
Inference: logical thinking or interpretation of observations based prior knowledge, experience or opinions; it is attempted explanations or conclusions based on data gathered from observations; any type of thinking process done from observations
Observation is what you see (or hear, feel, etc.)
Inference is what you think about what you’ve observed or figure out from what you’ve observed
Example: Testing lake water by checking small amounts, or samples, may allow the scientist to infer that all the water in a lake is safe.

9. Or: it was hot today so I’ll predict that it will be hot tomorrow too
Scientists make predictions.
Predictions: use of knowledge to explain what might happen in the future
e.g. (Example): Since the water has tested safe, I predict that no one will die from drinking it.
Or: it was hot today so I’ll predict that it will be hot tomorrow too

10. Practice: Write 3 observations & make one inference about this picture
Observation is what you see (or hear, touch, etc.)
Inference is what you figure out

11. Science is involved in solving problems in the natural world
Solving any problem requires organization.
In science, this organization often takes the form of a series of procedures or methods referred to as the scientific method.

12. Scientific Method: Common procedures used by scientists to gather information used in problem solving and in designing & doing experiments to test ideas & learn new things about the natural world.

13. Steps of the Scientific Method:
State the Problem or Ask a Question about the natural world
Gather Information or do some research so you can learn more about the topic
Form a Hypothesis- which is a testable prediction of what you think might happen in the test (experiment)

14. Steps of the Scientific Method:
4) Perform an Experiment-(Yeah, labs!)
5) Analyze Data-review & interpret the facts learned during the experiment
6) Draw Conclusions-after it’s all done, what did you learn from the experiment?
Sometimes models are used to help visualize your work or conclusions
Models are created to help see (or visualize) ideas in a way that’s easier to work from e.g. globes of Earth, drawings of cells, etc.

15. The Scientific Method starts when you…..
State the Problem or Ask a Question: It starts when you ask a question about something that you observe (How, What, When, Who, Which, Why, or Where?)
Observation: using our senses to collect or bring together information
What are your senses, anyway?

16. Gather Information: Do background research.
3) Form a Hypothesis: A question or statement that can be tested. If it can’t be tested, it’s not a Hypothesis

17. A hypothesis is a possible explanation for a set of observations.
A hypothesis must be proposed in a way that can be tested.
Hypotheses are tested by performing controlled experiments or by gathering new data (observations, etc.)
A hypothesis must be tested by doing experiments or by doing more observations before we know for sure that it is true
A hypothesis may be ruled out as not true or found to be correct (confirmed as valid), both are important to know

18. Example: How do organisms come into being?
Many years ago, people wanted to know how living things came into existence or how they started living or growing. They started with a question that asked:
How do organisms come into being?

19. One early hypothesis was spontaneous generation, or the idea that life could come from nonliving matter. For example, most people thought that maggots spontaneously appeared on meat.
Hypothesis: testable question or prediction
People used to think
that maggots appeared
spontaneously or
suddenly, all by themselves,
almost by magic

20. Maggots-
white caterpillar like creators that are part of a fly’s life cycle, they later
become flies

21. Francisco Redi observed that maggots appeared on meat a few days after flies were present.
In 1668 he proposed a new & different hypothesis: that maggots came from eggs that flies laid on meat.
A good hypothesis statement for this could be: If maggots come from flies, then they will appear after flies have touched eatable things
Hypothesis: testable statement or question that starts an experiment, it must be tested by more observations or by doing experiments before we know for sure that it is true

22. Perform an Experiment: A series of steps are followed to test a hypothesis using controlled conditions.
Redi decided to do an experiment to test his idea about how maggots appeared on food
Have you turned in all your signed forms & passed the safety test?

23. Controlled Experiment: experiment in which one variable is changed or controlled by the scientist and the other variable is measured or counted. All other variables are kept the same or constant
Variable: Something (a part of, a factor) in an experiment. It can changed, measured or kept the same (e.g. type of insect tested, type of food, location, temperature, time spent on experiment, etc.)
(e.g. = for example etc. = more examples)

24. What would happen if you changed too many variables at once
What would happen if you changed too many variables at once? Experimental Error!
You would not know which variable caused the results you get in the experiment
e.g. different temperatures, different types of food for the maggots to grow in, different lengths of time spent for testing

25. What would happen if you changed too many variables at once
What would happen if you changed too many variables at once? Experimental Error!
Too many variables make things too confusing. Two variables (one you change- or control- and one you measure) lets you know exactly what caused the effect you’re measuring
It’s a bad idea to have some maggots grown on carrots in your kitchen for one day, some grown on meat laying in snow for one week, some grown on oatmeal in the dessert for one month.
Was it the different clothes, hair cut, cologne or size that made one more popular? Too many variables to know for sure!

26. Independent variable (manipulated variable): factor in an experiment that a scientist changes or controls on purpose
It does NOT change because of what happened in the experiment!
e.g. covered or not covered jars (the jars themselves did not change because they were covered or not)
Dependent variable (responding variable): factor in an experiment that a scientist wants to observe or measure, it may change in response to the independent variable
e.g. how many, if any, maggots appear in each
Constants (controlled) variables: factors in an experiment that are purposely kept the same
Time, temperature, type of food, type of jars, etc.

27. Independent variable (manipulated variable): scientist changes Dependent variable (responding variable): it changes because of what happens during the experiment

28. Redi’s Experiment
Uncovered jars
Covered jars
Constants or Controlled
Variables:
Same jars, type of meat,
location, temperature,
same length of time, etc.
Good hypothesis: If flies land on meat, then maggots will grow on the meat

29. Redi’s Experiment Manipulated Variable: Several days pass.
Gauze covering that keeps flies away from meat
Several days pass.
Responding Variable:
maggots appear or not
Maggots appear.
No maggots appear.

30. Experimental & Control Groups
Experimental Group: Group being tested
This group experiences the independent (manipulated) variable-the one scientists change in the experiment
Control Group: Used as a comparison group
This group does NOT have the independent (manipulated) variable but it does have (experience) all the other parts of the experiment (constants or controlled variables)

31. Experimental and Control Groups

34. Independent variable (manipulated variable): factor in an experiment that a scientist changes or controls
It does NOT change because of what happened in the experiment!
e.g. how much water to give plants (the water itself does not change because of how much was added to the plants)
Dependent variable (responding variable): factor in an experiment that a scientist wants to observe or measure, it may change in response to the independent variable
e.g. how much the plants grew, if at all, because of how much water they were given
Constants (controlled) variables: factors in an experiment that a scientist purposely keeps the same
Time, temperature, type of plant, type of pots, type soil in each pot, amount of light each plant got, etc.

35. Warmup What is the Scientific Method?
Name the steps of the Scientific Method:
What is a variable?
Explain what a controlled experiment is:
What are constants in an experiment?
Explain the difference between the independent and dependent variable. Which variable affects the other?
What is the difference between the Experimental Group and the Control Group?

36. Warmup
What is the Scientific Method? Common procedures used by scientists to gather information used in problem solving and experimentation
Name the steps of the Scientific Method: 1. state the problem or ask a question; 2. do some research to learn more; 3. develop a testable hypothesis that you can base an experiment on; 4. do the experiment; 5. think about or analyze the data from the lab; 6. draw conclusions about what you learned in the lab
What is a variable? A part of an experiment that is changed
Explain what a controlled experiment is: experiment where only two variables are changed at a time
What are constants in an experiment? Things that are kept the same (constant) throughout the experiment
Explain the difference between the independent and dependent variable. Which variable affects the other? Independent (manipultated) variable the scientist changes on purpose & the dependent (responding) variable is measured during the experiment. The independent variable affects the dependent variable
What is the difference between the Experimental Group and the Control Group? The Experimental Group is being tested in the experiment, it experiences the independent variable. The Control Group is used as a comparison, it does everything the same (has all the contants) but does not experience the independent variable

37. Analyze Data: See if your data supports your hypothesis

38. Draw conclusions: A conclusion is a logical idea developed from doing an experiment, it answers the starting question or hypothesis and is based on data and observations

39. Researchers often work in teams to analyze, review, and check (critique) each
other’s work, including conclusions from experiments

40. Why would they want to do this?
Scientists need to check that other people’s work is correct. A review process helps ensure conclusions are valid (correct).
To be valid, a conclusion must be based on good, logical interpretations of well planned experiments and reliable data.
“You haven’t confirmed the Superstring Theory, this is a whisker from your beard !”

41. How does a scientific theory develop?
As evidence from many investigations or experiments done by many different scientists builds up, a hypothesis that has been found true many, many times may become so well supported that scientists consider it a theory

42. How does a scientific theory develop?
Theory: a well-tested explanation that unifies (ties together) many different observations or experiments

43. Scientific Theory vs. Common Use Theory
Important difference:
in everyday life, sometimes theory means a guess
(e.g. I think that girl likes me)
in science, an idea is tested many, many times and proves itself true over & over before it is called a theory
(e.g. I asked her to the prom, she said yes; I asked her to marry me, she said yes; we’ve been married 72 years. There is a lot of evidence that she likes me)

44. Science is an ongoing process that involves:
asking questions
collecting observations
making inferences
testing hypotheses

45. Scientific understanding is always changing.
Good scientists are skeptics who question both existing ideas and new hypotheses.

46. Science and Human Values
Decisions involve many factors besides scientific information, including:
the society in which we live
economic considerations
laws
moral principles
Citizens decide what to do when they vote.

47. Independent variable (manipulated variable): factor in an experiment that a scientist changes or controls on purpose
It does NOT change because of what happened in the experiment!
e.g. covered or not covered jars (the jars themselves did not change because they were covered or not)
Dependent variable (responding variable): factor in an experiment that a scientist wants to observe or measure, it may change in response to the independent variable
e.g. how many, if any, maggots appear
Constants (controlled) variables: factors in an experiment that a scientist purposely keeps the same
Time, temperature, type of food, type of jars, etc.

48. Independent variable (manipulated variable): scientist changes Dependent variable (responding variable): it changes because of what happens during the experiment