Designing Experiments

NS 1021: Introduction to Biology: Cells and Organisms

The Scientific Process: Designing Experiments

Introduction

The scientific process does not necessarily follow a linear series of steps. Frequently, once initial observations have been made and questions have been asked, preliminary experiments are done in order to help in the formation of a clear hypothesis. Once one or several hypotheses have been stated, experiments are designed to test them. An experiment must be planned carefully so that it clearly tests the given hypothesis or hypotheses.

Objectives

To understand and use the scientific process.
To find the fastest way to dissolve a biodegradable packing peanut.

Prelab discussion

List some techniques which are used to get materials to dissolve
Which of these techniques may be useful in getting a biodegradable packing peanut to dissolve?

Materials

biodegradable packing peanut
beaker
distilled water
other materials as determined by prelab discussion

The Challenge: Part 1

Using materials as discussed in your lab group, you have 45 minutes to determine how best to dissolve a single packing peanut. At the end of that time, be prepared to participate in a discussion with other groups on the scientific process you followed and why you followed it.

The Challenge: Part 2

Using the process as discussed in "Practicing Inquiry: Designing Controlled Experiments," design a series of controlled experiments to find the fastest way to dissolve a single packing peanut. Be sure to record a hypothesis or several alternative hypotheses before beginning your testing. Prepare to compete with other groups in a time trial at the end of the period.

Lab Report

Title: a few words which make clear what the topic of the lab was.
Minus 1 point if no title
A brief introduction explaining the purpose and challenge of the lab. Include an explanation of the scientific process in general.
3 points
Hypothesis/alternative hypotheses: What did you think, before starting to test, would be the fastest way to dissolve a peanut, and why did you think that?
2 points
Your process. State, step by step, the method you used to determine the best way to dissolve a peanut.
3 points
Your data. Include the times for each trial you did. Also include results of the rest of the class.
2 points
Analysis: Did your data support your hypothesis/hypotheses?
2 points
Your conclusions: Wrap it all up. Did your experiments fully test your hypothesis? Why did you choose the method you did? What would you do in future experiments on this question? Did the experiments or results generate any new questions?
5 points
Questions: Answer the "Follow Up Discussion Questions" at the end of the "Practicing Scientific Inquiry: Designing Controlled Experiments" handout.
2 points
Metacognitive analysis: What in this lab helped most with your understanding of the scientific process? What part of the process was the most challenging? What would you change?
1 point