1.1.2 The Scientific Method Process of the Scientific Method.
Scientific method
Transcript of Scientific method
Just What Is Science Anyway???
a journey through the scientific method...
Science is a process of inquiry - asking questions and
getting answers you do science there are many sciences
life science poli-science social science etc
Observation before you can ask a question - you need to
make an observation…
2 kinds Direct observation- done w/ the 5 senses
sight, touch, smell, aural, taste Indirect observation - done w/ equipment
thermometer, anemometer, balance...
The Scientific Method a very good way to do science easy to follow repeatable thorough is the way it’s really done in the field! (BUT NOT THE ONLY WAY!)
What’s the Purpose?? you need to state the goal of your
investigation - called the Purpose (or Problem) Statement it needs to be clear to you (and the reader)
exactly what you are investigating
The “magic” purpose statement
The purpose of this experiment is to determine the effect of ______(iv)_______ on the _______(dv)_______.
Procedure you need to list the steps that you are going
to (or did) take to carry out your experiment it must be so detailed so that anyone who
may dispute your work can reproduce exactly what you did
The Rope Problem!!!
Variables to vary - to change Independent (manipulated) Variable (IV) -
the part of the experiment that you change Dependent (responding) Variable (DV) -
the part of the experiment that changes as a result of changing the independent variable (the outcome)
more... Controlled Variables - the parts of your
experiment that do not change WHY have these?
Control Group - the part of the experiment that is your basis for comparison (you don’t do anything to this group)
An Hypothesis….. ..is an educated prediction - “educated”
implies that the predictions are based on research and your prior experiences.
Should be stated in “If... Then… statements Ex:“If a car’s mass is increased then it will
go faster down a ramp.”
Paper Towel Lab
Come up with an agreed general procedure
Procedure/variables might get altered Keep all other variables constant!!!
No out of control experimentation!) EVERYONE takes notes in lab group! Make sure you use measuring tools
properly. (accuracy counts in grade)
Data Presentation data tables
a simple way to organize your data graphs
to help your data make visual sense trends
Mass of cart (g)
Ramp angle (deg)
Ramp length (cm)
Time (s)
Ave. time (s)
40.00 45.0 35.0 11.30
40.00 45.0 35.0 12.10 11.70
25.00 45.0 35.0 10.90
25.00 45.0 35.0 11.90 11.40
Data table
Table 1: Cart speed based on cart Table 1: Cart speed based on cart massmass
Mass of cart (g)
Ramp angle (deg)
Ramp length (cm)
Time (s)
Ave. time (s)
40.00 45.0 35.0 11.30
40.00 45.0 35.0 12.10 11.70
25.00 45.0 35.0 10.90
25.00 45.0 35.0 11.90 11.40
Table 1: Cart speed based on cart Table 1: Cart speed based on cart massmass
Units of measure
Mass of cart (g)
Ramp angle (deg)
Ramp length (cm)
Time (s)
Ave. time (s)
40.0 45.0 35.0 11.30
40.0 45.0 35.0 12.10 11.70
25.0 45.0 35.0 10.90
25.0 45.0 35.0 11.90 11.40
Table 1: Cart speed based on cart Table 1: Cart speed based on cart massmass
Significant digits
Significant digits...
…are a way to show how accurate the measurements are
(depends instrument is being used) Example: Triple beam balance
measures to the nearest tenth of a gram, therefore all mass measurements should only go out one decimal point
Mass of cart (g)
Ramp angle (deg)
Ramp length (cm)
Time (s)
Ave. time (s)
40.0 45.0 35.0 11.30
40.0 45.0 35.0 12.10 11.70
25.0 45.0 35.0 10.90
25.0 45.0 35.0 11.90 11.40
Table 1: Cart speed based on cart Table 1: Cart speed based on cart massmass
Highlight important stuff
Mass of cart (g)
Ramp angle (deg)
Ramp length (cm)
Time (s)
Ave. time (s)
40.0 45.0 35.0 11.30
40.0 45.0 35.0 12.10 11.70
25.0 45.0 35.0 10.90
25.0 45.0 35.0 11.90 11.40
Table 1: Cart speed based on cart Table 1: Cart speed based on cart massmass
Give it a clear title
Conclusions INTERPRET THE DATA:
what do all of these numbers mean?
do they answer the problem statement?
why or why not?
Analyze for errors …
what factors skewed your data?how far off were the results?Look to see if any trials were
“outliers”What should be done next time
to reduce any errors?
Reflect…. What link to our studies did this lab
have? Did you learn anything new, any
surprises? Any comments or questions? Anything you might add? What happened with your hypothesis and
why was it right or wrong?
Precision vs. Accuracyif your data is accurate it is close to its true value
if your data is precise it is consistent from trial to trial
Precision vs. Accuracy
this is precise but not accurate
Precision vs. Accuracy
this is precise and accurate
Accuracy comes from________?Precision comes from________?
Answers: equipment
people
All Done...