it is the process that is used to find answers to questions about the world around us
TRANSCRIPT
What is the Scientific Method?
It is the process that is used to find answers to questions about the world around us.
The Scientific Method
The “tool” that scientists use to find answers to questions
Is there only one “scientific method”?
There are several versions of the scientific method
Some versions have more steps than others
They all begin with the identification of a problem or a question to be answered based on the world around us and
They provide an organized method for conducting and analyzing an experiment
5 Major Steps of the Scientific Method
1. Identify the Problem2. Form a Hypothesis3. Create and Perform an Experiment4. Analyze the Data (make conclusions)5. Communicate Results - OR- Modify
the Experiment and Start Over
1. Identify the Problem
What do you want to know or explain?
Do some research on the subject matter.
Write a question that addresses the problem or topic you want to investigate.
2. Form a Hypothesis
What is a Hypothesis? An educated guess based on
observations and your knowledge of the topic.
A testable explanation for an observation.
In other words, a suggested solution to a problem or questions
Written as an “If...then…” statement▪ Ex. IF you don’t study THEN you’ll get a bad grade on
the test
3. Create and Perform an Experiment
Follow the steps in your procedure to perform your experiment.
Record Data and Observations
What are observations? Something that you see,
feel, taste, or smell Something that can be
detected by your senses
3. Experiment - Vocabulary Control- Part of the experiment that is not
being tested and used for comparison
Variable- Any part of an experiment that can change
Independent Variable- Part of the experiment that is manipulated (what you are testing)
Dependent Variable- Part of the experiment that is affected by the change in the independent variable (what you expect to happen)
3. Experiment - Vocabulary
Validity – The procedure will accurately test the hypothesis Large sample size Adequate control (provides good
comparison) Only one variable is being tested
Reliability – when the experiment is redone, similar results are found (consistent)
3. Experiment – VocabularyLet’s practice …
Krusty Krab Breath Mints Mr. Krabs created a secret ingredient for a breath mint
that he thinks will cure the bad breath people get from eating crabby patties at the Krusty Krab. He asked 100 customers with a history of bad breath to try his new breath mint. He had 50 customers (Group A) eat the special ingredient breath mint after they finished eating a crabby patty. He had the other 50 customers (Group B) eat a regular breath mint after they finished eating a crabby patty. Both groups were told they were eating a breath mint that cures bad breath. Two hours after eating the crabby patties, 30 customers in Group A and 10 customers in Group B reported better breath than normal after eating a crabby patty.
Krusty Krab Breath Mints
5. What is the Control Group? a) Group Bb) Group Ac) Type of mintd) Curing Bad Breath
Hint- control groups DON’T have what is being tested
Krusty Krab Breath Mints
6. What is the Independent Variable? a) Group Bb) Group Ac) Type of mintd) Curing Bad Breath
Hint- the independent variable is WHAT YOU ARE TESTING
Krusty Krab Breath Mints
7. What is the Dependent Variable? a) Group Bb) Group Ac) Type of mintd) Curing Bad Breath
Hint- the dependent variable is what you expect to happen
Krusty Krab Breath Mints
8. What should Mr. Krabs conclusion be?
a) No conclusion- bad experimentb) His breath mints DO NOT cure bad
breath better than regular mintsc) His breath mints DO cure bad breath
better than regular mintsd) His breath mints actually make breath
WORSE!Last Slide
5 Major Steps of the Scientific Method
REVIEW… We have covered #1-3.
1. Identify the Problem2. Form a Hypothesis3. Create and Perform an Experiment4. Analyze the Data (make conclusions)5. Communicate Results - OR- Modify
the Experiment and Start Over
4. Analyze the Data
Charts & Graphs – This will help to organize and make sense of the data collected.
Conclusion – decided whether the original hypothesis was correct.
What is Data?
It is the information gathered during an experiment
Two main types of data Quantitative: Numerical (the most powerful
type of data)
▪ Ex. The plant grew 5 cm▪ Always measure in METRICS
Qualitative: Descriptive▪ Ex. The plant got bigger
Recording Data
Make charts, tables or graphs
Draw pictures or take photos
It is important to only state what is truly observed.
Observations VS Inferences
In our experiments, we often want to make OBSERVATIONS (not inferences) Inferences are often made after
experiments- like in the analysis or conclusion
Observations VS Inferences
Observations Any information collected with the
senses. The skill of describing scientific
events. Inferences
Conclusions or deductions based on observations
May be influenced by prior knowledge.
The process of drawing a conclusion from given evidence.
Practice: Observation vs. InferenceWrite down…A for observationB for inference
1. There is a representation of a face on one side of the coin.
2. The words printed on both sides of the coin are Latin.
3. The Latin word "Dei" means "God."4. The coin was made by deeply religious people.5. The date 1722 is printed on one side of the coin.6. The coin was made in 1722.7. The face on the coin is a representation of the
nation's president.
Make sure you know what you are observing!
OPTICAL ILLUSIONS
Is this image moving?
Are the streams moving?
How many prongs do you see?
What do you see?
Which way is the window facing?
What do you see?
Collecting and Displaying Data
Data Tables and Graphs
Artist Millions of CD’s Sold
Beatles 237.6
Elvis Presley 189.2
Michael Jackson 149.6
Queen 84.8
Variables
Ordered Pair
Units
Title
Data Table
Best Selling Music Artists
Data Table
Title- briefly describes the content of the data table
Variables- describe what information is being collected.
Units- describe the details of the information that was collected
Ordered Pairs- two pieces of data that correspond to each other.
Graphs
Used to show the relationships in data.
There are 3 main types:1. Pie2. Bar3. Line
Average Temperature and Rain in Las Vegas
Month
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Rain (mm)
11.4 14.2 12.3 12.8 4.8 5.2 2.5 9.3 12.6 6.6 5.6 10.8
Temp (°C )
7.5 10.6 13.5 17.8 23.3 29.3 32.8 31.5 26.9 20.1 12.7 7.6
Using data tables to make graphs
05
101520253035
Month
Amou
nt
Rain (mm) Temp (oC)
Average Temperature and Rain in Las Vegas
Using data tables to make graphs
Make sure you include:
• Title• X Axis –
Horizontal (Variables & Label)• Y Axis –
Vertical (Variables & Label)• Key• Plot points on
the graph (clearly identified)
More About Graphs and Data TablesBigger is better when it comes to
graphsDo not forget to LABEL and TITLE
your graphs
4. Analyze the Data (make conclusions) Is the data reliable?
Reliable means if another scientist does your experiment (or you do it again), will they get similar results? ▪ If so, your experiment is reliable▪ If not, your experiment is unreliable
Does your data support your hypothesis? Your conclusion would answer this
question This is where inferences are made.
5. Communicate Results or Modify
If your data is inaccurate or your experiment is flawed…
Rewrite your procedure to address the flaws.
If your original hypothesis is not supported by your data…
Decide how you might change your hypothesis
If you believe you need more support… Think about what you might do to
experiment further and give more support to your hypothesis
5. Communicate Results or Modify
If you believe your experiment is reliable and valid Validity is concerned with the
study's success at measuring what the researchers set out to measure.
Then you can summarize the important parts of your experiment and the results
Other scientists may then verify your results by doing your experiment themselves
After the experiments…
Theory - a set of hypotheses for a general phenomenon that are supported by many experiments Theories are generally accepted
principles in science They can change based on new
evidence- but it would require A LOT of new evidence
Theories covered in Biology this year:▪ Theory of Evolution▪ Cell Theory
▪ Theory of Genetic Inheritance