Scientific practices in the classroom
Katherine LeVanPhD Candidate
Holway Invasion Ecology
“Science is an organized body of knowledge and a method of proceeding to an extension of this knowledge by hypothesis and experiment.”
--Dr. Glenn Seaborg
A primer on the process of science
• Codifies reasoning that we all do everyday• Advantages include:– Removal of bias– Encourages multiple lines of evidence
Read an article about something
Read an article about something
Ex: I found an article that says plants need nutrients like nitrogen, phosophorus and potassium to grow.
LITERATURE I have an idea that…
LITERATURE I have an idea that…
Giving plants lots of nutrients will make them grow bigger, faster, have more fruit/flowers
LITERATURE HYPOTHESIS
P1
P2
P3
LITERATURE HYPOTHESIS
P1
P2
P3
Plants with more nitrogen added will be bigger
Plants with more nitrogen added will get larger, faster
Plants with more nitrogen added will make more fruit
LITERATURE HYPOTHESIS
P1
P2
P3
T1
T2
T3
LITERATURE HYPOTHESIS
P1
P2
P3
T1
T2
T3
= Nitrogen added
LITERATURE HYPOTHESIS
P1
P2
P3
T1
T2
T3
= Nitrogen added
Control
Experim
ental
LITERATURE HYPOTHESIS
P1
P2
P3
T1
T2
T3
Plant mass will be heavier
= Nitrogen added
LITERATURE HYPOTHESIS
P1
P2
P3
T1
T2
T3
Plants will grow faster
= Nitrogen added
Week 1 Week 2
LITERATURE HYPOTHESIS
P1
P2
P3
T1
T2
T3 Plants will make more fruit
= Nitrogen added
17 beans 7 beans
LITERATURE HYPOTHESIS
P1
P2
P3
T1
T2
T3
Statistics/Data analysis
LITERATURE HYPOTHESIS
P1
P2
P3
T1
T2
T3
Statistics/Data analysis
Is there a difference?Is that difference biologically
important?
LITERATURE HYPOTHESIS
P1
P2
P3
T1
T2
T3
Statistics/Data analysis
WRITE A NEW
ARTICLE
LITERATURE HYPOTHESIS
P1
P2
P3
T1
T2
T3
Statistics/Data analysis
WRITE A NEW
ARTICLE
Science is self correcting
• Science works because multiple groups are trying to uncover the same true phenomena
Science is self correcting
• Science works because multiple groups are trying to uncover the same true phenomena
• If someone gets a weird result that isn’t right, other studies will show that it was a freak occurrence
Science is self correcting
• Science works because multiple groups are trying to uncover the same true phenomena
• If someone gets a weird result that isn’t right, other studies will show that it was a freak occurrence
• Different people approach the same question multiple ways – If multiple types of evidence point to the same
conclusion, then we accept a fact as true
Types of experiments
• Manipulative experiments– See previous example– Control vs. treatment
• Observational studies– Collect data on existing organisms– Problem: hard to attribute cause and effect
Reproduction in plants
Plants have a variety of strategies for reproducing.
Annuals vs. Perennials
Reproduction in plants
Plants have a variety of strategies for reproducing.
Annuals vs. Perennials
Reproduction in plants
Plants have a variety of strategies for reproducing.
Annuals vs. Perennials
Echinopsis grusonii-Golden barrel cactus
Data collection: methods
• Determine size of cactus– Height, circumference
• Count the number of flowers (active/senesced)• Count the number of bees visiting in 2 mins
Let’s go into the field!
Communicating science:writing a lab report
• Intro– Tell us a little bit about the subject of interest– What was your hypothesis? Predictions?
Communicating science:writing a lab report
• Methods– What is the minimum amount of information
someone needs to replicate what you did?
Communicating science:writing a lab report
• Methods– What is the minimum amount of information
someone needs to replicate what you did?
– “Ten cacti were surveyed”
Communicating science:writing a lab report
• Methods– What is the minimum amount of information
someone needs to replicate what you did?
– “Ten cacti were surveyed”
Communicating science:writing a lab report
• Methods– What is the minimum amount of information
someone needs to replicate what you did?
– “Four people measured each cactus”
Communicating science:writing a lab report
• Methods– What is the minimum amount of information
someone needs to replicate what you did?
– “Four people measured each cactus”
Communicating science:writing a lab report
• Results– What story do your data tell you? How will you
plot the data? How will you label the axes?
Communicating science:writing a lab report
• Results– What story do your data tell you? How will you
plot the data? How will you label the axes?
Note: NEVER put ‘raw’ data into a lab report NEVER interpret your results in this
section.
Communicating science:writing a lab report
• Discussion– What do the data mean in light of what you
expected? What others have found? Interpret your findings and draw connections.
Comparison of your data & mine
By collecting data on reproduction in closely related species, we can find out how prevalent one strategy is over another
Coast Barrel Cactus in San Diego
02000
40006000
800010000
1200014000
0
5
10
15
20
25
Cactus Size (cm3)
Num
ber o
f Fru
it
Coast Barrel Cactus in San Diego
02000
40006000
800010000
1200014000
0
5
10
15
20
25
Cactus Size (cm3)
Num
ber o
f Fru
it
Classroom applications
• Science is about explaining “observed, measured, and predicted” phenomena (K+)
Classroom applications
• Science is about explaining “observed, measured, and predicted” phenomena (K+)
• It’s not science until you share it! Via drawings/reports (K+)
Classroom applications
• Science is about explaining “observed, measured, and predicted” phenomena (K+)
• It’s not science until you share it! Via drawings/reports (K+)
• Represent data with bar graphs (1st+), scatterplots (3rd+), histograms (3rd+)
Classroom applications
• Science is about explaining “observed, measured, and predicted” phenomena (K+)
• It’s not science until you share it! Via drawings/reports (K+)
• Represent data with bar graphs (1st+), scatterplots (3rd+), histograms (3rd+)
• Repeated sampling is important! (3rd+)
Classroom applications
• Conduct an observational (K+) or experimental study (4th+)
Classroom applications
• Conduct an observational (K+) or experimental study (4th+)
• Introduce independent/dependent variables (5th)
Classroom applications
• Conduct an observational (K+) or experimental study (4th+)
• Introduce independent/dependent variables (5th)
• Document linear/non-linear trends in scatterplots (7-8th)
Any questions?