The student is expected to demonstrate that repeated investigations may increase the reliability of results.
The student uses scientific inquiry methods during laboratory and outdoor investigations.
Sample Size and Multiple Trials: Holt, Reinhardt, and Winston (PDF) - Increasing the number of trials and the sample size in an experiment reduces the effect of random, uncontrollable variables on the results. It also ensures that the experiment was completed and measured properly. Read more about multiple trials in this excerpt from a science fair guide.
Data, Statistics: Visionlearning (website) - Detailed information on statistical terminology, the role of statistics in describing variability—and reliability—in data, as well as the relationships between variables. Includes references for further reading and additional learning modules.
Balloon Car: ZOOMsci/PBS Kids (PDF) - This simple, fun investigation demonstrates that repeated trials increase the reliability of test results, and that changing a single variable can impact the outcome significantly.
- Supporting Lessons
- Assessment Ideas
- Literature Connections
- Additional Resources
Flicking With Force: Utah Education Network (website) - Three balls of different mass are flicked with equal force and the distances they travel are compared.
Elaboration Lessons and Extensions
How Many H2O Drops Can Fit On a Penny? Science Spot (PDF) - Student investigate how many drops of water can stay on the flat side of a penny and average the data of multiple trials to obtain more accurate results.
Chain Gang: PBS Kids (PDF) - Students conduct an experiment to determine the relationship between mass and length of a pendulum and the time it takes to complete a swing. Multiple trials are averaged to reduce the amount of measuring error and to ensure consistent results.
After completing one or more lessons on this page, make sure that students record their observations and calculations in their science notebooks. Have each student write a paragraph that describes how the results did or did not change as a result of repeating their investigations.
What’s the Plan? Designing Your Experiment. Hyde, Natalie (ISBN-13: 978-0778751540)
Solving Science Questions: A Book About the Scientific Process. Chappell, Rachel M. (ISBN-13: 978-1600445422)
Elementary School Design Packet: NASA eClips (PDF) - Introduction to a formal process for designing and testing a product or experiment to solve a given scientific problem.