1. Chapter 1 How Scientists Work
Scientific Method
Chapter 1
How Scientists Work

2. Lecture Outline – The Scientific Method
PowerPoint Notes
textbook questions
Keys

3. How Scientists Work: Solving the Problems
Much of biology deals with solving problems
These problems can be environmental, ecological, health related, etc.
No matter what types of problems are being studied, scientists use the same problem-solving steps called…
The Scientific Method

4. Scientific Method Definition
The scientific method is-
A logical and systematic approach or process to problem solving. 
An organized way of using evidence to learn about the natural world.

5. Scientific Method Listing the Steps
Make an Observation
Define the Problem
State the Hypothesis
Design an Experiment to test Hypothesis
Collect and Record Data
Analyze Data
Draw Conclusions
Report Results
If needed, Do more investigation

6. 1. Make Observations
As we all know, frogs have four limbs.
An observation is recording a description of something unusual in your natural world by using your senses
What’s up with these froggies?

7. 2. Questioning Recognize, state or define the problem
Ask scholarly questions:
What…?
When…?
Where…?
Who…?
Why…?
How…?

8. 3. Researching Gather information related to the problem by:
Reading, observing , measuring, taking samples, etc.
How frogs normally develop from eggs
The % of frogs with the deformities
Number of other species in the pond with deformities
Previous or new pollutants in the pond
Change in amount of UV (sunlight) exposure on eggs

9. 4. Hypothesizing A hypothesis is:
An educated guess, trial answer, possible solution, prediction
Must written as an “If…Then…” statement
Must be testable or measurable
Is based on your research and previous experience

10. 5. Experimenting An experiment is a procedure to test your hypothesis
Design an experiment that will realistically examine the claim made in the hypothesis

11. Control and Experimental Groups
used as a standard of comparison
the group containing the factor (variable) that has been changed
Control group:
Experimental group:
(manipulated or independent variable)
Two groups of jars
Uncovered jars
Covered jars

12. Variables in an Experiment
Variables - Factors that can be changed
Controlled Variables - all the variables that remain constant
Manipulated Variable or Independent Variable - factor in an experiment that a scientist purposely changes or makes different
Responding Variable or Dependent Variable - the outcome or results, factor in an experiment that may change because of the manipulated variable…. what a scientist wants to observe or measure

13. 6. Collect and Record Data
Information in the form of observations and measurements made in an experiment
Types of Recorded Data
Quantitative - observations that are numerical
Ex: amounts, frequency, measurements
Qualitative - observations that are of a descriptive nature
Ex: color, smell, texture, taste, sound

14. Number of Plants in each area
Data
Data must be grouped neatly and organized into:
tables
charts
Figures
graphs
A Table has rows and columns to organize data.
Number of Plants in each area
Plant #
Area A B
Area C D 1 10 6 25 30 2 5 3

15. 7. Analyze the Data Examine data tables, charts, and graphs
Examine experimental notes
Look for trends, patterns, and averages
Report what your data shows

16. 8. Draw Conclusions A conclusion is a restatement of the hypothesis:
Ex: The data from the experiment either supports or rejects the hypothesis.
Support your conclusion with specific, numerical data gathered from the experiment

17. 9. Determine Limitations
Scientists look for possible flaws in their research
They look for faulty (inaccurate) data
They look for experimental error or bias's
They decide on the validity of their results
They make suggestions for improvement or raise new questions

18. 10. Publish Results Communication is an essential part of science
Scientists report their results in journals, on the internet, or at conferences
This allows their experiments to be evaluated and repeated
Scientists can build on previous work of other scientists
Redi’s experiment
on insects generation

19. Scientific Theory
A theory is an explanation of a set of related observations or events based upon proven hypotheses and verified multiple times by detached groups of researchers

20. Scientific Law
Scientific Method
Scientific laws represent the cornerstone of scientific discovery
They must be simple, true, universal, and absolute
If a law ever did not apply, then all science based upon that law would collapse