Replication Versus Repetition

Repetition

&

Replication

Learning Objective:

Students will be able to compare and contrast
REPLICATION and REPETITION and identify examples of both.

2

Repetition
Repetition is the “repeating” of your OWN investigation for
accuracy.

Done by the SAME PERSON.

Completing Multiple Trials.

4

Trial Number

Plant Height (cm)
after 5 days

1

30 cm

2

31 cm

3

30.5 cm

4

30 cm

5

31 cm

Repetition Example: Multiple Trials

Replication

Replication occurs when the

investigation is "replicated"

or COPIED by a different

investigator.

Repeated activity done by

DIFFERENT people

5

Dr. Spike copied Dr. pony’s experiment
and got similar results!

The plants grew and average of 30 cm in 5 days.

If scientific experiments are
replicable they are more valid and reliable.

Replication Example: By Others
Dr. Spike copied Dr. Pony’s experiment

6

11

REPETITION is done by the SAME person with MULTIPLE TRIALS for precision of results.

REPLICATION is done by DIFFERENT
people to see if they achieve similar
results and improve accuracy.

Let’s Review!

Multiple Choice

An environmental group contacts Nancy to get her experimental procedures so that they can check her results.

• Replication

• Repetition

Multiple Choice

Dr. Allen has been reading about another scientist’s research in a physics journal. She plans to do these experiments herself and see if she gets the same result.

• Repetition

• Replication

Multiple Choice

A scientist does THEIR OWN experiment over 3 times to check their results.

• Repetition

• Replication

Multiple Choice

Joshua goes to Silver River each week for 4 weeks and collects 5 samples of water to test the pH.

• Replication

• Repetition

Multiple Choice

Alyssa has taught her pet rat to run a maze. She thinks that the rat will go faster if she puts its favorite treat at the end. She has the rat run the maze ten times with the favorite treat and ten times with a regular food pellet. She uses a stopwatch to measure how long it takes for the rat to get to the reward.

• Repetition

• Replication

Multiple Choice

Keanna was mixing a batch of glue and borax solution to make silly putty and discovered a new substance that glows in the dark. She gave Ryan her specific amounts of ingredients and the steps of her procedure. She asked Ryan to try the experiment to see if he gets the same results.

• Repetition

• Replication

Multiple Choice

Jermaine was given a set of 5 metal cubes. He calculated the densities of each to determine the type of metal in each. The densities were really close to each other, so he asked his friend Dustin to do the same experiment and see if he gets the same results.

• Replication

• Repetition

Multiple Choice

Walter is testing golf balls. He drops three different brands of balls from 40 cm and measures how high they bounce. He drops each ball 10 times.

• Replication

• Repetition

Multiple Choice

Jerry baked chocolate chip cookies that wound up looking like muffins. He asked DeeDee to use the same directions and see if her cookies also look like muffins.

• Replication

• Repetition

Multiple Choice

A local ecologist measures the temperature of a nearby lake each day at noon for 1 month.

• Repetition

• Replication

Multiple Choice

Mariah places six identical pails of water in direct sunlight and measures the temperature of the water in each pail every ten minutes.

• Replication

• Repetition

Multiple Choice

Francis asks Lillian for her chemistry experiment’s procedure so he can confirm her findings.

• Replication

• Repetition