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?