Transcript Document 7223060

§112
The Nature of Science
•In this unit WE will review the steps of the
scientific method and practice using science
in everyday life.
•On the following slides, the red sections are
the main points; summarize the slides in your
notebooks.
•Underline words = vocabulary!
Notes – The Cornell Method
• For this
class, place
the topic or
guiding
question in
the left hand
column.
• As you get
more skilled,
you will
create your
own topics
and
questions.
• Summarize the notes in
the right hand column:
– NO complete sentences
– Abbreviations
– key phrases
– Sketches + drawings
What is Science?
• Defined by the National
Academy of Sciences, it is the
"use of evidence to construct
testable explanations and
predictions of natural
phenomena, as well as the
knowledge generated through
this process."
• Science is the organized way
of using evidence to learn
about the natural world.
• The goals of science:
– to investigate
– to predict future events
– to explain natural events
http://icestories.exploratorium.edu/dispatches/wpcontent/uploads/2008/06/img_0255.jpg
Skills in Science
• Observing uses one or
more of the five senses
(sight, hearing, touch,
smell, & taste) to
gather information
about events or
processes.
• Observing allows you
and scientists to gather
information about the
subject they are
investigating.
Tiff Shao, a NYC native and biology
major, is studying biodiversity in Costa
Rica for Duke University’s Organization
of Tropical Studies. Although Tiff is far
from Duke, the classroom is not too far
away. Link
Skills in Science Cont.
This image is view of the meteorological data
collected for weather stations and used by
forecasters to predict the weather. Link
• Through observing,
scientists collect
information, called data.
• Scientists then use this
data to make inferences.
• An inference is an
interpretation based on
data and observations or
prior knowledge.
• A prediction is a
statement or claim that a
particular event will occur
in the future (EX the
weather).
Scientific Method
•
The scientific method is
a procedures that
scientists use to answer
a question:
1. Purpose/Problem
2. Hypothesis
3. Experiment
4. Data Collection
5. Analysis
6. Conclusion
http://3.bp.blogspot.com/_AZ11xOAXRiY/RuXpxTqqRKI/AAAAAAAAAA0/GJxdM9
EmHg8/s400/scientific+method.gif
Purpose or Problem
http://campus.murraystate.edu/academic/faculty/tderting/bio116/sci_method.jpeg
•Typically after making an observation a scientist will begin to
question why?
•What problem do you want to solve? What do you seek to learn?
•You must research is already known about the problem.
Hypothesis
•A hypothesis is a possible explanation or answer to a
scientific question, often called an educated guess.
•A hypothesis must be testable and capable of being
supported by observable evidence; the evidence typically
comes from an experiment.
Experiment
• An experiment tests the
hypothesis to see if it is correct.
• Scientists:
– use instruments that
measure and collect data
– keep detailed notes on the
procedures, so the
experiment can be
duplicated
– repeat the experiment
through several trials for the
most accurate data possible
• The information from
an experiment is data.
– qualitative
descriptive (EX
color, odor, or
sound)
– or quantitative
numerical (EX #s).
http://sageseeds.info/tutorials/unwilt.gif
Data
This image above provides qualitative
data while the image below provides
quantitative data during an experiment
(Link).
Analysis
• Scientists analyze (look closely at) the data and study
the results.
• Scientists determine how to represent that data,
whether in charts, graphs, tables, etc.
http://barbarabray.net/wp-content/uploads/2010/07/datacollection.jpg
Conclusions
• At the conclusion of the experiment, the scientist asks,
“What did I learn?” and discusses the results of their
analysis.
• A conclusion states whether or not the hypothesis was
correct.
• Often the data does not support the hypothesis which
means the whole process can start over again with new
questions to be answered!
Types of Experimental
Investigations:
1. Descriptive – based mainly on observations
– No controlled variables
– EX making models, dissections, observing animals in
the wild
Jim and Jamie Dutcher spent
six years in Idaho in a tent
within the world’s largest wolf
enclosure in order to observe
and document the behavior of
these wild animals. They got
really close to the wolves and
made many unique photos of
wolves in their natural habitat
(Link).
Types of Experimental
Investigations Cont:
2. Comparative - involve collecting data on different
groups under different conditions
– to make comparisons
– EX two plants - one with fertilizer, one with a
different fertilizer
Types of Experimental
Investigations Cont:
3. Experimental - the
manipulation of variables
– variables are actively
manipulated
– EX rye grass seeds in
three cups, 1watered
daily, 1watered every
other day, 1 without
water (control)
http://www.jardinguide.com/wp-content/uploads/2009/06/potts_6243694_xs.jpg
What is a controlled
experiment?
• A controlled experiment is an experiment in which all
factors except one remain constant (are the same).
http://www.green-planet-solar-energy.com/images/water-science-experiment.gif
How do scientists control
variables?
• In order for an experiment to test
only one variable, other parts of
the experiment must be the
same. These are constants.
• Some experiments involve a
control group; the control
receives NO treatment and is
used to compare.
http://www.yaledailynews.com/img/2007/12/12/475f86e3f3a56_SC
ITECH.jpg
Independent
(AKA Manipulated) Variable
• The variable the scientist changes is called the
independent ( or manipulated) variable.
• “I, the scientist” = independent variable
http://csam.montclair.edu/images/csam/weston_main.jpg
Dependent
(AKA Responding) Variable
• The variable that is expected to change in response is
the dependent (or responding) variable.
• The “data I collect” = dependent variable; it is what we
measure.
http://www.aanda.org/index.php?option=com_image&format=raw&url=/articles/aa/full/2006/19/aa
1538-04/img33.gif
Dependent Variable!!!
Independent Variable!!!
– Independent Variable = “I the scientist” am controlling
the temperature of the water.
– Dependent Variable = Speed of diffusion of the food
dye.
http://upload.wikimedia.org/wikipedia/commons/e/eb/Diffusion.gif
http://www.green-planet-solar-energy.com/images/water-science-experiment.gif
Vocabulary in Action!
What Graph?
http://www.jpowered.com/php-scripts/adv-graph-chart/images/graph-screen.gif
• The type of graph you will use depends on the type of data in
your experiment.
– Line – use for infinite data (i.e. time)
– Bar – static or finite data (i.e. number of days in a week)
– Pie – good visual for %
Reading A Graph
•Graphs allow us to
interpret data and
predict by reading
carefully.
•How would interpret
the line graph
presented here?
“NASA released data showing this last meteorological year to be the hottest
ever in their 130 year records.
The meteorological year, which ended on November 30th, boasted a global
average temperature of 14.65°C. This was an increase of 0.12°C on the
previous warmest year, 2005, which had a global average of 14.53°C. The
average is taken by measuring temperatures both over land and sea…”
By Jonathan Frost, 2010: the hottest year on record (Link).
DRY-MIX
Dependent Variable!!!
http://www.business-analysis-made-easy.com/image-files/xy-axis.gif
Independent Variable!!!
• Remember scientists
show their data in graphs.
• Remember the acronym
DRY MIX when graphing
for science.
– Dependent/Respondin
g variable = Y axis.
– Manipulated/Independ
ent = X axis.
• Sketch the graph to
remember the axes.
What is the difference?
This powerful electron microscope
allows researchers to see tiny microbes
and cells as never before; the system
includes a camera to record the data.
Link
• A hypothesis is a tentative,
testable statement for a
specific problem or question.
• A scientific theory and is wellestablished, highly-reliable
explanations of events
[natural and physical] from
multiple, independent
theorists.
– Atomic Theory
– Cell Theory
– Theory of Evolution
• Theories may change as new
areas of science and new
technologies are developed,
providing new information.
Unit Conclusion
• The scientific method will be used throughout the year during our
class experiments.
• Scientists study the world through experiments using very similar
procedures and steps.
http://www.calvin.edu/academic/science/summer/images/bioresearch2
009-720px.jpg
• As scientists in this classroom, safety is the number one priority!