INFERENCE MAKES THE DIFFERENCE
Inference and logical reasoning are key elements in both the
scientific method and mathematical problem solving. This series of lessons,
lasting 2-4 class periods, focuses on developing this specific skill. It
directly links inference to the science of archaeology. The student will
learn about how an archaeologist makes inferences from artifacts to determine
what life was like for past civilizations. They will work in cooperative
groups and make inferences about an imaginary household based on modern
day "artifacts" found in garbage. The Real Science! video used
in this lesson attempts to motivate all students' interest in a career in
archaeology as well as provide a positive female scientist role model in
Real Science! #102: Mysteries of the Past
3-2-1 Classroom Contact #28: How Do you Know? Dig It Up
Students will be able to:
1. define inference and observation.
2. make inferences supported by picture clues.
3. identify the types of tools an archaeologist uses.
4. identify the steps an archaeologist uses to
5. make and support inferences based on imaginary artifacts from the garbage
of an imaginary household.
Texas Assessment of Academic Skills (TAAS), Grade 4
#1: Acquire scientific data and/or information.
#2: Sequence, order and/or classify scientific data
#3: Communicate scientific data and/or information.
#4: Interpret scientific data and/or information.
#5: Make inferences, form generalized statements and/or make predictions
using scientific data.
#7: Draw conclusions about the process(es) and/or outcome(s) of scientific
#8: Relate and apply scientific and technological information to daily life.
#11: Determine solution strategies and analyze or solve problems.
- 1 coffee mug
- coffee or other beverage
- 1 clear drinking glass
- transparency of attached graphic (or 1 copy per student)
- large sheet of butcher paper
- recording sheet for viewing (one per student)
Per group of 3-5 students:
- paper bag
- newspaper to cover desks
- strawberry basket for a sifter
- 1/2 inch paint brush
- toothbrush for cleaning artifacts
- recording sheet for cataloging artifacts and making inferences
Per group of 3-5 students:
- survey sheet
- grocery bag with a variety of different "imaginary trash"
artifacts objects, for example-
- food wrappers,cereal boxes
- utility bills, junk mail, store receipts
- restaurant receipts, bill receipts
- sports programs, movie or theater ticket stubs
- newspaper clippings, computer print outs
- occupation oriented magazines, hobby magazines
Shoe Box Activity
Per group of 3-5 students:
- graphing recording sheet
- ruler marked in centimeters
- shoe box
- 1 lb. (approx.) modeling clay
- cliff dwelling
Gather students together on the carpet. Show them a regular size coffee
mug, but do not let them peek inside the mug. Ask, "Can you tell me
exactly what is in this mug? (Yes! Well, not exactly. Maybe coffee.) Without
looking, do you know for sure? (no) Do you want some clues? (yes) It is
a liquid. I can drink it. Any guesses? (Accept reasonable guesses.) Do you
know for sure? (not yet) It is a dark brown color. It is warm. (Accept more
guesses.) Could it be hot chocolate? Could it be hot tea? Could it be coffee
as you guessed before? It could be coffee or hot chocolate or tea. You don't
know for sure yet, but those are all good guesses."
"They are good guesses because you used all the clues I gave you and
your own knowledge about different types of drinks. Maybe you even know
which of these drinks I prefer. All this information would help to make
an intelligent guess. The guesses you made are also called inferences."
Write the word inference on the board. "An inference is a knowledgeable
guess based on clues. You inferred what the liquid in my cup is without
the opportunity to observe it."
Write observe and observation on the board. Ask, "What does observe
mean to you? What do you do when you observe something? (You use one or
more of your five senses.) If you are allowed to observe what is in this
mug, could tell what it is? (yes) Would you like to observe what is in my
coffee mug?" (yes) Pour the liquid into a clear drinking glass. Ask,
"Now do you think you know for sure? What's the difference between
an inference and an observation?" (An inference is a guess based on
clues. An observation is based on using one or more of your five senses
at the object first hand.)
Ask, "Now that you have observed that there is coffee in my cup, could
you infer that I am a coffee drinker, even if you have not seen me take
a sip? (yes) I think you all did a great job of making inferences about
what is in my coffee mug. Would you like to try to make some more inferences?"
Show the graphic of the man in an apron on the overhead or on paper, one
copy per student. "Observe this picture. What do you see?" (man
standing in a kitchen, lots of dirty dishes, room a big mess...) Continue
to take observations and then ask the students to make some inferences.
Ask, "Are there any clues about what this man's life is like? What
inferences can you make? What can you infer?"
Emphasize to students that they must make an inference based on clues. Direct
them to record their inference and the clues they used to come up with the
inference. Challenge them to come up with at least 10 inferences about this
man and what his life is like. Students can return to their desks and work
in cooperative learning groups. [Note: There are many inferences to be made
about this picture. Examples: He is a single father. His wife is out of
town or it is his turn to do the dishes. The man has children. One is in
elementary school (math paper on the wall) and one is a baby (high chair
and rattle). He is not very wealthy (holes in shoes, patches on jeans).
He does not have good vision (glasses in pocket). He is clumsy (broken dish).
Someone in the house plays baseball (bat). It is the winter holiday season
(holly in vase, snow outside). It is evening, so he is probably tired.]
After about 15 minutes of work time, call on groups to share their inferences
and record them on butcher paper. Review the list with the class and evaluate
whether or not the inferences are valid. Is there a sufficient clue to support
this inference? Allow for discussion and/or defense of inferences made.
After a brief review of what the students have learned and practiced today,
the lesson can be concluded for
Gather the students and review yesterday's lesson on observation and inference.
Say, "You have done a great job using your observation and inference
skills. Can you think of when these skills would be used in real life? (Accept
all reasonable answers, i.e. doctors, detectives) There are scientists who
depend on having great inference skills to do their work. Do you know the
names of those scientists? If you have ever studied dinosaurs, you can probably
thank a paleontologist for that information. [Write the word `paleontologist'
on the board.] A paleontologist studies dinosaurs and other early life forms
on our planet. A paleontologist works in the area of science called paleontology.
Dinosaurs became extinct about 65 million years ago! How do these scientists
study something that is not even alive anymore? They can not go out and
observe an animal the way a zoologist would. So how do they do it? (Accept
all answers.) They must rely on fossils, tracks, and any evidence they can
piece together about what the dinosaurs were like. They depend on clues.
They make inferences."
Ask, "What about scientists who study groups of people who are no longer
alive? Do you know what those scientists are called? (archaeologists) Write
the words archaeologist and archaeology on the board. Say, "Archaeology
comes from two Greek words: ARCHAIOS means ancient, LOGOS means study. Archaeologists
study ancient civilizations or groups of people. How can they study a civilization
that is no longer here? (Accept various answers.) Archaeologists are like
detectives who investigate the past. They must rely on clues just like the
paleontologists! They must make inferences based on the clues left behind.
Using all the clues available, archaeologists try to piece together a picture
of the ancient people they are investigating. The goal is to learn what
type of place or environment these people lived in. An archaeologist may
want to know how they built and furnished their shelters; what they ate;
how they obtained and prepared their food; what kinds of tools they used;
their customs and religious beliefs."
Say, "In order to learn these things, an archaeologist observes artifacts.
Artifacts are the objects that ancient people used and then left behind.
Do you know what those things might be? (tools, weapons, household items,
jewelry, clothing, religious or special ceremony items) Over time these
things get covered up with earth due to weather or changes in the earth's
surface. Sometimes the people themselves buried them. Archaeologists carefully
remove, observe and make inferences about the objects left behind."
Tell students, "Today you are going to view a video called
Real Science! that will give us a first hand look at how an archaeologist
works on the job called a "dig". You will need to listen and record
important information throughout the program, so get your pencils and listening
ears ready. First I want you to listen to find out the name of the people
being studied and the location of the "dig".
BEGIN the Real Science! video after the paleontology
segment when Teresa, wearing the red sweater, says, "Long after the
dinosaurs became extinct...." PAUSE after Teresa says, "Our
reporter Isaac White spent the day with her at a prehistoric ruin."
Ask, "Who are the ancient people being studied? (Anasazi. Write it
on the board.) Where is the dig? (southwestern Colorado) [Have students
locate Colorado on the map or globe.] This dig is to find out more about
this Native American tribe. However, archaeologists study ancient people
all over the world. Now listen to find out what a 'kiva' is." RESUME
PAUSE after Isaac says, "We are excavating in a square kiva
which is an underground or subterranean room." Write the word 'kiva'
on the board. Ask, "What is a kiva? [Record the definition by the word.]
What inference can you make about why the Anasazi would want an underground
room? [Note: Help the students to infer that it could be needed for protection
from the weather and/or enemies or has a religious place.] These are all
"In this next segment, I want you to observe what kind of tools the
archaeologist uses to get the artifacts she needs. Record as many as you
can." RESUME the video. PAUSE when the word "archaeology"
appears on the screen with a brush sweeping across it. "What tools
did you see? Can you name them?" (bucket, scooper, brush, dust pan
, pick, trowel, sifter/strainer) Record the names on the board as students
share them. REWIND if needed to review the tools shown. Ask, "What
do these tools help the archaeologist to do? (find artifacts) What do the
artifacts help the archaeologist to do? (make inferences) What types of
artifacts do you think might be found here?" Record student responses.
Tell students, "Listen for what this archaeologist is interested in
learning." RESUME the video. PAUSE when the archaeologist
says, "It looks like we've got some full buckets. Let's go strain."
Ask, "What is unusual or different about this site? (The kiva is square
instead of round.) With more clues from artifacts, perhaps this archaeologist
can make a guess or inference about this. Perhaps it is a special kiva of
some sort. The Anasazi are the people who lived in this area. I wonder what
their name means? Let's watch to find out." RESUME the video.
PAUSE when you hear the words, "Anasazi means 'ancient ones'.
If their own name means 'ancient ones', their tribe must have been around
for many years. Listen again to when these people likely lived in this area.
REWIND and RESUME at the last starting point. PAUSE
when the screen shows the words, "The Anasazi people lived in the Four
Corners region starting more than 2000 years ago." Say, "The Anasazi
people left or abandoned this area in 1280. How many years ago was that?
How would we figure that out? [Subtract the present year from 1280. 1996-1280
= 716 years] That means that all the Anasazi artifacts found here are over
700 years old. Let's take a look at the cliff dwellings." RESUME.
PAUSE the video. Ask, "What inferences can you make about them?
Why would anyone build their homes here? (protection from enemies, hot sun
or cold weather, special place for religious reasons) In this next segment,
we see what an archaeologist does after gathering the artifacts from the
field. Listen as we go to an archaeologist's lab to find out what the first
two steps are after the artifacts are gathered." RESUME video.
PAUSE the video when the archaeologist who is sitting says, "We
will look at it in more detail later to see if it's tools." Ask, "What
do archaeologists do first? (wash artifacts) Ask, "Why would an archaeologist
do that? (to more easily observe them) What do they do next?" (sort
into groups) Listen to what happens next." RESUME the video.
PAUSE when Isaac is looking through the microscope and the archaeologist
who is seated says, "It doesn't have that real granular appearance
to it." Ask, "What is the step after sorting? What does cataloging
mean? [You may need to tell students that every artifact must be documented
and recorded on paper with a designated number. This is to help keep track
of all the artifacts found.] Can you add another tool to your list of equipment?"
(microscope) RESUME video.
PAUSE when you see the archaeologist reach for the bowl on the shelf.
Ask, "Why is she wearing gloves? (Artifacts must be handled carefully.)
Look carefully at the artifact she is about to show Isaac. Listen for any
inferences she makes about this bowl." RESUME video. PAUSE
after the archaeologist puts the bowl back on the shelf. Ask, "Did
you hear an inference?" (that the holes on the side of the bowl were
repair holes) RESUME the video. PAUSE when Isaac shakes hands
with the archaeologist. Ask, "Did you hear another inference? [Rewind
if necessary.] (that curved pottery piece means that it comes from a dipper
or ladle) Remember that the Anasazi people of long ago are not here to ask
about these things, so archaeologists can only observe artifacts and make
inferences about them."
Ask, "Do you think you would like to be an archaeologist? You are already
on your way! Listen to these tips." RESUME the video until the
end of this segment and then stop before it goes into the segment on astronomy.
Ask students, "Would you like to go on another dig? Do you want to
learn about ancient people that lived right here in Texas over 6000 years
ago? Let's watch this segment of 3-2-1 Classroom Contact. Listen for the
definition of anthropologist.
BEGIN the video at the beginning. PAUSE when Zee says, "Sometimes
they study people who live thousands and thousands of years ago." Say,
"Remember from the last video, archaeology is a branch of anthropology.
An archaeologist is an anthropologist who is interested in studying ancient
people. In the next segment, listen for the place this archaeologist (anthropologist)
is taking Todd and Mary. RESUME the video. PAUSE after the
narrator says, "We are on our way to Mile Canyon near Langtry, Texas."
Say, "Let's locate Langtry, Texas on a map. [It is in the southwestern
part of the state close to the Big Bend area.] RESUME the video.
PAUSE when the archaeologist says, "This is where they seemed
to have concentrated in terms of living." Ask, "Where else have
you seen rock or cliff dwellings? (Anasazi people in southwestern Colorado)
Listen to the next segment to find out what this archaeologist is interested
in finding out about this ancient people. RESUME the video.
PAUSE when Todd says, "Which one are we going to go to?"
Ask, "What is this archaeologist interested in learning?" (how
people survived) RESUME the video. PAUSE when Todd asks, "About
how many people could have lived in there?" Ask the class, "Do
you remember the cliff dwellings of the Anasazi in Colorado? How are they
alike? (both on side of cliffs) How are they different?" (no visible
buildings) RESUME the video. PAUSE when Todd asks, "How
big is this?" and the archaeologist answers, "About the size of
a football field. Ask, "How big is a football field? (100 yards) Listen
for any inferences the archaeologist makes as he enters the cave. Every
time you think you hear an inference, put a tally mark on your recording
sheet. RESUME the video.
PAUSE when Todd says, "How can you be certain that they ate
something like that?" Say, "I heard three inferences about the
ancient people who lived in this dwelling?" Ask students to share any
inferences they can remember. Record them on the board. (Possible inferences:
The people lived in the center of the cave. They pitched their garbage off
to the side of the campfire. The snails climbed in the cave to get cool.)
Say, "Getting back to Todd's question, how can an archaeologist be
sure what prehistoric people ate? Any ideas? (Accept any reasonable answers.)
Let's listen to find out." RESUME video.
PAUSE when Mary says, "Shall we take a look?" Say, "The
only way to know they ate something is to prove that it went through their
digestive system. Toilet areas... Sounds like unpleasant research. Let's
see what Mary and Todd do with their next very unusual artifact." RESUME
PAUSE when Todd says, "Copperlites are what scientists call
fossilized feces." Ask, "Is there any reason to be worried about
germs? (No, all bacteria and germs died long ago. The copperlite is 6,000
years old!) Record copperlite on your recording sheet. Listen for how this
copperlite will help an archaeologist figure out what these people ate."
RESUME the video.
STOP the video when you see the frame of the cliff dwelling and Todd
says, "We know because we can analyze what they left behind."
Ask, "What did these people of 6000 years ago eat? (rodents, plants,
insects) This may sound like an unusual diet, but then maybe what we eat
today may be unusual to the people 6000 years from now. [Note: This is a
possible stopping point for the day. If time permits, continue with the
Ask, "Wouldn't it be fun to go on a real archaeological dig and uncover
artifacts of ancient people? We could really put our inference skills to
work! In today's activity you are going to pretend that you are an archaeologist
of the future investigating what life was like for a family here in 1996.
Each group will get a different bag full of artifacts found in the excavated
garbage area of various houses in an Austin neighborhood. Follow the directions
step by step. Each group will get a tool bag. [Show each tool in the bag
and how it is used: newspaper to cover desks, spoon for digging, strawberry
basket for sifter, paint brush and toothbrush for cleaning) You will work
in cooperative groups to sift through some excavated earth with your sifter,
clean off your artifacts, and record each artifact you found by name. After
you have done that you will observe each artifact closely and make at least
one inference about each artifact. Do a careful job! It is very important
that you take very good care of your artifacts because you will be making
inferences about the family that threw the garbage out. Your group will
need to work together to answer the survey about your the family's garbage."
Pass out the tool bags and the dig bags. Instruct students to first cover
their desks with newspaper from the tool bag. [Note: You may choose to do
this activity outdoors. It makes clean up much easier.] The carefully chosen
artifacts can make for some interesting inferences!
Shoe Box Activity
For more practice with making inferences, try this shoe box activity with
your class. Prior to the activity, arrange the modeling clay into hills
and valleys in the bottom of each shoe box, making the contours different
in each box. Cut ten numbered slots in a line in the shoe box lid. Make
the holes large enough for the end of a regular school ruler to be inserted.
The students are not aware of how the clay has been arranged. Direct the
groups to slide the ruler into the slots in number order and record the
depth at each slot in centimeters on grid paper. Have the students infer
what the bottom of the box looks like, based on their observations, and
then draw a diagram to illustrate the shapes on the bottom of the box. The
students can then uncover the box and compare their drawing to the clay
Visit or write the Lower Colorado River Authority Kingsland
Archaeological Center, approximately 50 miles from Austin, Texas. This center
offers students a rare opportunity to inspect a working archaeological dig
which has yielded more than 100,000 artifacts dating back as far as 5,000
years ago. Students can view archaeologists at work and participate in excavating
with archaeological tools and other hands-on activities. In advance of your
visit, contact LCRA, P.O. Box 220, Austin, TX 78767. Phone 1-800-776-5272.
Internet: Santa Barbara Museum of Natural History maintains
a program through the Internet called Ask-a-Curator. Classes can send in
questions about archaeology and anthropology to scientists working with
the museum. The e-mail address is
firstname.lastname@example.org. Teachers should
send an introductory message to make sure the program is still in operation
and to introduce themselves to the scientists. To insure that the curator
is not overwhelmed with mail, it is best to compose one or two questions
as a class rather than having students send in questions individually. Some
questions which may be appropriate for this unit could include:
What was the most exciting discovery you've
What artifact was the most difficult to identify?
What is the most remote place you've ever dug in?
How much time do you spend in the field?
Do archaeologists work for places other than museums and universities?
Why did you want to become an archaeologist?
Language Arts: Students discuss and then write about what people
of the future would infer about our culture if they uncovered one or more
of the following artifacts: a video arcade, playground equipment, a frisbee,
a super hero comic book.
Language Arts: Students write about what they would put in a time
capsule. What objects would best represent you, your family, your class
this year, your city? Tell why you would choose each object for the time
Language Arts: Students discuss and/or write about the following.
A large development company wants to build a shopping mall. They have applied
to the city to get a permit to build it. Many people want the mall and think
it would be a great thing for the community. It would create jobs for people
as well as be convenient shopping and office space in the community. When
the company begins bulldozing, a large number of artifacts are uncovered.
Experts are brought in and this appears to be a large deposit of artifacts
that would help in gaining information about that culture. What should
Reading Rainbow #509: Mummies Made In Egypt
I Can Be an Archaeologist by Robert Pickering
Mitzi and Frederick the Great by Emily A. Mc Cully
Motel of the Mysteries by David Macauley
Mummies Made in Egypt by Aliki
Visiting the Art Museum by Larry and Marc Brown
1995-1996 National Teacher Training Institute / Austin
Master Teacher: Jo Ann Carreon-Reyes
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