Thinking like a Scientist

1
Thinking like a Scientist

• The Scientific Inquiry/Process
• And
• The Scientific Method

2
What is Science?

• Science includes knowledge of the physical
  universe and the ways our knowledge is acquired.
• Science is a method of finding things out.

3
The Scientific Inquiry/Process

• There are two parts to the Scientific
  Inquiry/Process
• 1. Observations
• 2. Inferences
• 2a. Predictions

4
Observations

• Observing is using one or more of your senses,
  (sight, hearing, smell, taste, or touch), to
  gather information about the world.
• Example seeing the black chalkboard, smelling
  lunch cooking, tasting a sour lemon, hearing my
  voice, and feeling the smooth desk top.

5
Observations

• Observations can be either qualitative or
  quantitative.
• Qualitative observations are descriptions that do
  not use numbers colors, smells, texture,
  sounds. (quality)
• The classroom walls are yellow.
• Quantitative observations are descriptions that
  use numbers counting objects, measurements,
  etc. (quantity)
• There are 21 students in the room.

6
Inferring

• Making an inference, or inferring, is explaining
  or interpreting an observation or statement.
• Example
• Observation The sky is cloudy and gray today.
• Inference It probably is going to rain today.

7
Inference

• Base your inference on accurate qualitative or
  quantitative observations.
• Use prior knowledge and recent observations when
  making an inference.

8
Predicting

• Predicting is making an inference about a future
  event based on current evidence or past
  experience. One way to make a prediction is to
  look for a pattern. In science, predictions are
  usually tested.
• When you make a prediction in science, try to
  make it as specific as you can, dont just guess.

9
The Scientific Method

• There are basically six major parts to the
  scientific method.
• Problem or question
• Optional (Background information)
• 2. Hypothesis
• Design/Perform Experiment
• Collect/Interpret Data
• Conclusion
• Communication
• Optional (Additional comments or additional
  questions to further test).

10
Posing a Question

• Scientists design experiments to answer questions
  or solve problems.
• Does adding sugar to the water in a vase of
  flowers keep the flowers fresh?
• How do people get colds?

11
Hypothesis

• A hypothesis is a possible explanation for a set
  of observations or answer to a scientific
  question. Hypotheses are based on a persons
  observations and previous knowledge or
  experience.
• A hypothesis, in science, must be testable.

12
Designing and Performing an Experiment

• There are three parts to designing and performing
  an experiment
• Variables and Operational Definitions
• Materials
• Procedures

13
Variables

• Every experiment involves several variables, or
  factors that can change.
• For example Will houseplants grow faster if you
  make the room warmer? To answer this question,
  you decide to grow plants at different
  temperatures.
• The variable that you purposely change,
  temperature, is the manipulated variable or
  independent variable.
• The factor that may change as a result of the
  manipulated variable, how fast the plants grow,
  is the responding variable or dependent variable.

14
Variables

• You try
• You are planning an experiment to find out
  whether the rate at which water freezes depends
  on the shape of its container.
• What is the independent variable?
• What is the dependent variable?

15
Variables

• Controlling variables are very important.
  Controlling variables means keeping all
  conditions the same except for the manipulated
  variable. In the experiment on temperature and
  plant growth, you have to control other variables
  that might also affect growth rate such as
  using identical plants both being ferns, equal
  amount of soil, same amount of water, etc.

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Variables

• Name some controlling variables for the
  following
• You are planning an experiment to find out
  whether the rate at which water freezes depends
  on the shape of its container.

17
Operational Definitions

• An operational definition is a statement that
  describes how a particular variable is to be
  measured, or how an object or condition is to be
  recognized.
• Example Lemon juice, vinegar, and certain other
  substances are acids. To find out whether a
  substance is an acid, place a drop of the
  substance on blue litmus paper.
• Operational Definition Substances that cause
  the litmus paper to turn pink are acids.

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Operational Definitions

• Write an operational definition for each
  underlined idea
• On a cold day, let the water in the pan freeze
  outdoors.
• You will test these two fertilizers to determine
  which one helps plants grow faster.

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Operational Definitions

• Give an operational definition for the following
• You are planning an experiment to find out
  whether the rate at which water freezes depends
  on the shape of its container.

20
Review - Variables

• You are planning an experiment to find out
  whether the rate at which water freezes depends
  on the shape of its container.
• Independent Variable
• Dependent Variable
• Controlling variables
• Operational Definition

21
Materials

• Before you carrying out your procedures, you need
  to list your materials. Include measurements,
  such as 1 liter of water, or 2cm by 3cm of a
  sheet of paper. Materials should be listed to
  the exact quantity.
• When writing and performing your procedures, go
  back and modify materials if needed.

22
Procedures

• The procedure describes what you plan to do and
  identifies the data you plan to collect.
• The procedure is a step-by-step description of
  how you will change the manipulated variable and
  observe the effects upon the responding variable.

23
Collecting/Interpreting Data

• During an experiment, you collect data. Data may
  include measurements, color change observations,
  journaling observations, etc.
• After you collect data, you need to interpret
  what the data means. You can interpret data by
  making tables, charts, graphs, calculations
  (averages), or reviewing journal comments.
• When interpreting data, look for patterns or
  trends in data information!

24
Conclusions

• Drawing a conclusion means making a statement
  summing up what you have learned from an
  experiment.
• When asked to make a conclusion after an
  experiment, do not state, this experiment was
  fun. This is not a scientific statement.
• Your conclusion is usually related to your
  hypothesis. Determine whether your experiment
  supports your hypothesis or not. If your
  experiment did not support your hypothesis, try
  to determine why.

25
Communication

• Scientists communicate using written or printed
  word, such as Published Journals (Educational
  Psychology Journal) or lab reports.
• Lab Reports contain the following sections
• 1. Problem/Question
• Optional Background information/research
• 2. Hypothesis
• 3. Design/Perform Experiment
• a. Variables and operational definitions
• b. Materials
• c. Procedures
• 4. Data Collection/Data interpretation
• 5. Conclusion
• Optional Additional research questions
  or comments.

26
Scientific Theories

• Why is testing a scientific question over and
  over again important? A scientific theory is a
  well tested scientific concept that explains a
  wide range of observations. An accepted theory
  has gone through repeated testing and basically
  provided the same results.

27
Scientific Laws

• Scientific Law This is a statement of fact meant
  to explain, in concise terms, an action or set of
  actions. It is generally accepted to be true and
  universal, and can sometimes be expressed in
  terms of a single mathematical equation.
  Scientific laws are similar to mathematical
  postulates. They dont really need any complex
  external proofs they are accepted at face value
  based upon the fact that they have always been
  observed to be true.
• Some scientific laws, or laws of nature, include
  the law of gravity, the law of thermodynamics,
  and Hooks law of elasticity.