Elementary Science

Science Focus LessonSC.5.N.2.2Practice of Science/ Replication

Polk County Public Schools

SC.5.N.2.2Benchmark: Recognize and explain that when

scientific investigations are carried out, the evidence produced by those investigations should be replicable by others.

Essential Question: How can scientists support each

other by replicating experiments others have done?

Vocabulary:experiment evidence replicable valid

Gathering Valid EvidenceScientists seek answers by

testing hypothesesHypotheses are tested and

verified by collecting evidence through experimentation and observation

Evidence is a collection of data helpful in forming a conclusion or judgment

Evidence must be replicable in order to be considered valid and accurate

A hypothesis that is validated by evidence is considered to be correct

Replicable EvidenceEvidence must be replicable

in order to be validReplication means that

trials must be repeated many times in order to establish a pattern which would help to answer a scientific question

Scientists conduct hundreds of trials in an experiment. Students conduct at least three trials when they do an experiment…but more trials is even better!

Trial Hot Cold1 5

min8

min2 4

min7

min3 5

min7

min4 6

min7

min5 5

min8

min

Replicable EvidenceEvidence must be replicable in

order to be validReplication also means that

other scientists can repeat the experiment and get the same results

Scientists must keep accurate journals so that others can know exactly how to repeat the experiment

Scientists must communicate with one another so that they know about one another’s experiments

Replicable Evidence can Validate a HypothesisEvidence is considered valid

when…many trials have been

performed and a pattern has been established in the data

other scientists have conducted the same experiment and gotten the same results

Valid evidence helps scientists understand the answers to scientific questions

Summarizing Explain to your shoulder partner

the importance of evidence being replicable. Partner A will go first for 15 seconds. Partner B will summarize partner A’s answer. Then switch roles.

Replicating ExperimentsScientists replicate

experiments by communicating with other scientists and repeating the experiment in exactly the same way

Scientists must use the SAME UNIT OF MEASURE or they will not be able to compare their results

Different units of measure make it impossible to replicate the results

Trial My Data

Your Data

1 820F 260C

2 850F 270C

3 880F 260C

4 840F 280C

5 900F 300C

See how different the data looks when one scientist uses customary units and another uses metric units!

Replicating ExperimentsScientists replicate

experiments by communicating with other scientists and repeating the experiment in exactly the same way

Scientists must use the same TOOLS when they replicate another experiment

Different tools make it impossible to replicate the results

Replicating ExperimentsScientists replicate

experiments by communicating with other scientists and repeating the experiment in exactly the same way

It is important that the repeated experiment FOLLOW THE PROCEDURES exactly

Different procedures makes it impossible to replicate the results

SummarizingOne Sentence Paraphrase

Write what you have learned about replicating evidence in one sentence!

Share your sentence with your shoulder partner.

Guided Instruction:1. Gabriel is designing an experiment to see

whether sugar or artificial sweetener will attract the greatest number of ants. Which statement best describes why Gabriel should write down his experimental procedure?

a. The exact experiment can be repeated by others and the results compared.

b. The experiment can be changed by others to get different results.

c. The data will help people decide what type of sweetener to use.

d. The data will show people which ants are more common.

The answer isIt is important to

write very specific procedures so that others can replicate the experiment!

A

Guided Instruction:2. Two scientists were conducting

experiments. They each tested the same hypothesis. They made different observations and reached different conclusions. What will the scientists need to do to determine which conclusion is correct?a. Write a new hypothesis.b. Ask other scientists to do the same

experiment.c. Test other hypotheses.d. Write two conclusions.

The answer isAlthough the scientists

tested the same hypothesis, they did not read one another’s experiments so they did not follow the same procedures

Now it is time for them to share their experiments so that others might be able to replicate their results

B

Guided Instruction:3. Jamal is a research scientist. He works with

other scientists to carry out experiments. They repeat experiments over and over again. They compare and contrast their work and results. Why do scientists compare and contrast the results of their work?a. It helps them reach valid conclusions.b. It helps them become friends.c. It allows them to choose the best data to

report.d. It is more fun to work together.

The answer isScientists compare and

contrast their results to see if their evidence was replicated by other scientists

Evidence that is replicated is considered to be valid and can help to answer scientific questions

A

Guided Instruction:4. Zack and Josh did the same lab activity from

their science book. When they compared their data, they found out that they got very different results. What should they do next?a. throw out their data and copy someone else’s

datab. ask the teacher who is correctc. review their experiments to see if they can

tell what caused the difference.d. use Josh’s data because he is a better student

The answer isIt is important to

understand what differences caused the students to get different results

The boy should check their units of measure, the tools that they used, and other parts of their procedure such as time of day, etc.

C

SummarizingRally Table:Pass a piece of paper and a pencil

around the table. Each student adds something that they know about replicating evidence.

Check Your Understanding 1. Three scientists in different counties have been

trying to find a cure for a disease. Each scientist has been doing a different experiment. What would be the BEST way for these scientists to find a cure quickly?a. publish their results to show that the other scientists

are wrongb. decide which scientist is doing the best experiment

and repeat his experimentc. continue working separately so they don’t mix up

their experimentsd. communicate with each other to explain their work

Check Your Understanding2. What would happen if a person did not write

clear procedures and someone else tried to copy their experiment?a. the results would be slightly differentb. the results would be the samec. it would be easy to do the same experiment d. there would be no way to replicate the

experiment.

Check Your Understanding3. Kaitlyn grew plants outside in different soils for

her school science fair. She did her experiment three times. Each time, she recorded plant height daily and also wrote observations in an experiment log. The second time she did the experiment, her data was very different from the data in the other two experiments. Which of the following observations in Kaitlyn’s experiment log might explain the difference?a. She watered her plants the same amount each day.b. It rained for three days during the second experiment.c. The plants were all grown on the patio behind her

house.d. She followed her procedure very carefully each time

Check Your Understanding4. A famous scientist did an experiment and

published his results. When a scientist in another country repeated the experiment he got very different results. What should the second scientist do?a. tell everyone the first scientist was wrongb. decide his results must be wrongc. review both experiments to determine why

the results were differentd. change his data to match the famous

scientist’s data

Check Your Answers1. D2. D3. B4. C

SummarizingWrite a paragraph to summarize the

essential question. Be sure to include a topic sentence and at least 3 supporting sentences.

How can scientists support each other by replicating experiments others have done?