Lesson Plan | 1
HOW DO SCIENTISTS COLLECT DATA?
SAMPLING ACTIVITY
Length: 40 minutes (20-minute video plus
20-minute activity and discussion)
Age: Grades 6-12
Overview
Through a recorded talk by MSU graduate
student Madison Nixon, students will learn
about agricultural ecology, sustainability,
pest management and how climate change
may impact the future of wheat production
in Montana. The hands-on activity helps
students understand how scientists sample
for weed species, richness and diversity.
Background
A common difficulty in scientific research
is sampling. A sample is something that is
collected from a larger population. Samples
provide information, called data. Sampling
is the act of taking samples, i.e. counting
elk in Yellowstone National Park, or collecting weed species in a wheat field. Scientists, such as ecologists, need to collect
a lot of samples (often from large populations) in order to find answers to their
research questions. Often times, scientists,
such as ecologists, need to collect samples from large populations. It is often not
practical or even possible to count all the
members of a population, especially in large
areas of land. A population can be so large,
and sometimes spread out, that counting
it would be like trying to count the number
of grains of sand on a beach. To get around
these problems, scientists take data from a
smaller portion of the population. Samples
are then used to make inferences about the
entire population.
Learning Outcomes:
Objective 1: Help students understand
why sound sampling methods, conducted
within a realistic time frame, are crucial in
achieving helpful data.
Objective 2: Show students one or more
ways to accomplish sampling weed communities and how to calculate weed species
richness, density and diversity.
MSU graduate student Madison Nixon coordinates a weed sampling activity at the Montana Teen
Science Café. Photo by Suzi Taylor.
Materials and Required
Technology:
• Varying amounts of at least three types
of fake plants and/or flowers
o Fake plants/flowers can be
purchased at any craft store
o 100+ “weeds” works well for this
exercise in varying “species”. (The
video example uses 150 total weeds
from five different species)
• A bag or box to put the “weeds” into
• A way to calculate and record sampling
results, e.g., pen, paper and a calculator
• MS PowerPoint and projector
Glossary of Terms:
Species Richness: the number of species
present
• i.e. dandelion and creeping thistle
= 2 species present
Species Density: the amount of each
species in a given area
• i.e. 3 dandelions and 5 creeping
thistles per square meter
Species Diversity: each species’ percent of
the total number
This material is based on work supported by the National Science
Foundation under Grant EPS-1101342. Any opinions, findings and
conclusions or recommendations expressed in this material are
those of the author(s) and do not necessarily reflect the views of
the National Science Foundation.
• i.e. 3 dandelion + 5 creeping thistle
= 8 total weedy plants
• 3 dandelion/8 = 0.375 X 100 =
37.5% of the weeds are dandelions
• 5 creeping thistle/8 = 0.625 X 100
= 62.5% of the weeds are creeping
thistle
Activity
1)Watch the Teen Science Café talk by
Madison Nixon called “It’s Tough to be
Wheat in a Changing Climate!”
https://youtu.be/q1z-eSCuEk0
2)Briefly discuss why weeds are a topic
of interest to people (i.e. yield loss in
agriculture, invasive and/or noxious
species) and why people may want to
know species richness, density, and
diversity of weedy species in a field or
wildlife area.
3)Show students an example of a weed
sampling method.
Present the students with a hypothetical
sampling situation related to weeds. e.g.,
There is a 10-square-mile wheat field and
you are acting as researchers who need to
get an idea of weed species richness, diversity, and density for this field.
• Each student represents a sampling
plot. Ask half of the students to blindly
take 2 plants from the bag or box (low
sampling density). Ask the other half of
the students to take 8 plants from the
bag or box (high sampling density).
Note: the number of plants sampled
(high, low, etc.) should be modified
depending on total population size.
• As a class, calculate species richness,
density, and diversity for the two
sampling densities.
In the video example, 150 plants are
included in the sample. Instructors do
not need to use 150 plants, but should
know the actual species richness,
Suggested Alterations:
The above activity can be modified to fit
any time frame, space and age group.
• With more time, add more levels of
sample size i.e. low, med, high, etc.
• Scatter the plants and flowers on
the ground and have the students
conduct the sampling in a pattern,
using sampling frames (i.e. a frame of
a known size) within a time limit. For
example, ask them to sample using
the “W” sampling pattern (in groups
works best).
“W” sampling pattern (orange) with 20
sampling areas (purple). (optional extension
activity)
diversity and density of the whole
“weed population” prior to conducting
the activity.
4)For the “low” and “high” sampling
groups, compare their results to those
of the actual population.
5)Discuss why more samples are usually
more representative of the actual
population, but how time and resource
limitations often make it difficult to
collect a sample size near that of the
actual population.
In conclusion, researchers must design a
sampling method that will implement the
largest sample size possible and within a
reasonable time period and budget.
• Make it more difficult by asking
students to design and then implement
their own sampling pattern (in groups
works best), using sampling frames,
within a time limit. The latter takes the
lesson a step further to introduce the
topic of non-bias sampling and why
it is very rare to have the time and
resources to sample all the weeds in
an area of interest.
• Instead of purchasing fake flowers/
plants, educators can download free
“weed sampling activity cards” from
http://eu.montana.edu/climb
Lesson Plan | 2
LESSON PLAN AUTHOR
Madison Nixon is
a graduate student
at Montana State
University. She
is pursuing her
masters in Land
Resources and
Environmental Science. Madison
has a BS in Sustainable Food and
Bioenergy Systems and a BA in
Latin American and Latino Studies.
Teaching has long been a passion
for Madison. She taught with the
Bozone Ozone Greenhouse Bus,
shared her masters research with
kids through the Teen Science
Café at Montana State University,
and currently teaches afterschool Spanish to k-5 students in
Bozeman, Montana.
Examples of sampling frames. (optional
extension activity)
ABOUT THE MONTANA INSTITUTE ON ECOSYSTEMS
The Montana Institute on Ecosystems is a community of scientists and partners that studies Montana’s complex ecosystems, including
the impacts of climate change on ecosystems and the ways in which people and nature are interconnected. Formed in 2011 with
funding from the National Science Foundation’s EPSCoR program, the IoE has offices at Montana State University and the University of
Montana. Partners are located at other Montana University System campuses and Montana tribal colleges.
The culminating research and outreach product of the EPSCoR / IoE will be the Montana Climate Assessment (MCA), which involves
university researchers, decision makers, and other stakeholders with the goal of providing timely and relevant information for the
citizens of the State. The inaugural MCA will focus on climate issues that affect agriculture, forests, and water resources in Montana.
View more education and outreach resources at the Climate in My Backyard site: http://eu.montana.edu/CLIMB
CLIMB is an educational outreach program serving K-12 teachers and informal educators.
M O N T A N A
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