1. Experiments and Variables Experiment 3.1 Using a Series of Experiments
4/9/2019
Exploring Creation with General Science Week 6 - Mod 3 How to Analyze and Interpret Experiments
Sections:
Introductions
Experiments and Variables
Experiment 3.1
Using a Series of Experiments
Experiment 3.2

2. High-temp Superconductors…
Introduction
We’ve learned about the Scientific Method.
Let’s look at how to apply it.
Think about the failures…
Why they got wrong conclusions…
Percival Lowell & the Mars canals…
The BCS Theory – what was it again?
High-temp Superconductors… 2

3. Introduction To do science well, you need to think about…
Care in designing your observations and experiments.
How to avoid flaws in your experiments.
Different ways to test your hypothesis or theory to avoid missing data.
If you put in more forethought, usually this equals reliability in your outcome. 3

4. REVIEW: Science Defined
Science is a Branch of Study…
- for the collecting & classification
- of OBSERVABLE facts
- to formulate general laws
- about the world God has blessed us with.
What’s an observable fact?
It is something that you can ______ and describe to a non-observer. 4

5. Experiments & Variables
Experimental Variables – an aspect of an experiment which changes during the course of the experiment.
Lowell – Mars canals – one reason for his mistake – eye strain. 5

6. Experiments & Variables
Experimental variables aren't necessarily bad, sometimes they are very useful.
Sometimes the only way a scientist can learn something is by comparing the results of the experiment when different experimental variables are changed.
But you need to know which things ARE variables are which things are NOT!
Ask yourself: did that thing affect the outcome of my awesome experiment??? 6

7. Experiments & Variables
Unrecognized variables can lead to flawed experiments.
You need to CONTROL for your variables.
Recognizing & changing variables in a controlled way helps you design a better experiment which in turn, helps you design a better scientific law.
Handout chart for Experiment 3.1 7

8. Experiments & Variables
Experiment 3.1 – “A Floating Egg”
Experimental variables can often be used to learn a lot from an experiment. This experiment will show you what that means.
In your lab write up, here are some questions to answer…
What did you see – describe in words and pictures. 8

9. Experiments & Variables
Questions cont.:
What changed over the course of the experiment?
Did the density of the water change?
How did it change?
What were the variables? 9

10. Experiments & Variables
Questions cont.:
How did the variables affect the outcome?
Did the density of the object change?
What if the water temperature was different – hotter or maybe freezing? Would that have made a difference?
Adding salt changed what? 10

11. Experiments & Variables
Remember Experiment 1.1 – Density
– objects of lower density floated on top of objects of higher density.
Direct and indirect variables.
Direct variables are necessary and affect the outcome of the experiment.
Indirect variables are unnecessary and don’t affect the outcome. 11

12. Experiments & Variables
What about these unnecessary variables…
Different eggs or kinds of eggs?
Different glasses – taller or shorter?
Amount of water in the glass – less, more?
Would these have affected our outcome?
So when you build an experiment, you want experimental variables (direct), but you want to control for them. These are the things you learn from. 12

13. Experiments & Variables
And be on the lookout for unnecessary (indirect) variables. We need to analyze the experiment for these.
When we find indirect ones, either eliminate them as best you can or account for their affect on the experiment, but it is best to eliminate them.
“On Your Owns” 3.1 to 3.3 13

14. Using a Series of Experiments
Now that we know a little bit about how to analyze an experiment, we will get some experience doing a series of experiments dealing with the same idea.
Perform Experiment 3.2 – “Which Boat Will Move?”
Let’s make a chart to collect our data… 14

15. Using a Series of Experiments
The big experimental variable was the ____.
The 1st boat we put in had NO motor, so we call that our CONTROL.
Defined: a “Control” is defined as a variable or part of the experiment to which all others pieces can be compared.
So we compared the no-motor boat with ones that had a motor. Why? This gets to the point of the experiment. 15

16. Using a Series of Experiments
What are we trying to find? Which is the best ______.
Since the soap boat moved lots more than the others, we can conclude that the soap motor was doing something to make the boat move.
But what was it?
Our next experiment is to learn “why” the soap motor performed best. 16

17. For next time… Write up Experiment 3.1 – “A Floating Egg” and turn in.
Write up Experiment 3.2 – Which “Boat” Will Move?“ and turn in.
Do “On Your Owns” 3.1, 3.2, and 3.3
Read the rest of Module 3. 17