The goal of an experimental investigation is to determine how changes in an independent variable affects another variable, which is called the dependent variable.
Remember: When designing an Experimental Investigation it is important that you only have one independent variable and one dependent variable. All other variables must be controlled, meaning they must stay the same.
FYI: Controlled variables are not the same as a Control for your Investigation. The following will explain this.
Start Experiment Design:
I want you to understand some of the thought processes for designing an experiment that meets Science Fair Project requirements.
1. You need to have a purpose for your investigation. At this point you may not know exactly what you want to do but let’s assume you want to work with plants. I’d search the web and find different project ideas about plants.
You will find ideas on this page?
Let’s assume you decide to investigate how light effects plant growth. At this point you need to write a basic purpose. I point out that this is might only be a BASIC Purpose, meaning you may need to improve it.
Basic Purpose of Investigation: How light effects plant growth.
I’ll come back to the purpose, but next you need to write your science fair question.
2. The question for an experimental investigation must identify both the independent variable and the dependent variable. Your basic purpose identifies light as the independent variable and plant growth as the dependent variable.
Don’t Forget: The independent variable and the dependent variable for an experimental investigation must be measurable.
Measuring the Independent Variable
How does one measure light?
Light is very general. You need to be more specific about the independent variable. You will get the point after reading the following questions.
Do you want to measure how different types of light sources, such as sunlight, artificial light, or colored light effects plant growth? This is a good idea for a science project.
Do you want to measure how changes in the amount of one type of light effects plants growth?
This is another good idea for a science project.See ????? for more ideas for how light affects plant growth.
You may have other ideas about the light you want to use, but for this article, I will give examples for measuring the amount of one type of light.
The Independent Variable is the amount of light the plant received.
Ideas for how to change the amount of light.
1. Use sunlight which changes during the day as well as from one day to the next.
You can also use direct and indirect sunlight.
2. If you use artificial light you can decide when and for how long the plant will receive this light. You also have the option to control the wattage of light used–its color–type (fluorescent, UV, incandescent). Just use the same type of light for each test plant–see controlled var
iables below.
Think of blood as a gas/ fuel for the car ( your body). If there is no fuel, there's no movement (dead) so when the fuel tank is damaged the car won't function properly.
So if the heart becomes damaged, or weakened it would start making blood clots and damage the organs that need blood to function properly. The circulatory system wouldn't function properly and because other organs depend on the circulatory system it would cause a chain reaction, affecting other body systems. <span />
May occur in oceans is a type of transforms boundary is a region where earthquakes occur
Answer:
Only options a reflects the instances with valid experiment or conclusion.
Quality of any experiment depends upon two things reliability and validity. Reliability is measure of regeneration of results every time an experiment is performed under specific conditions.
Validity is measure of accuracy of results of an experiment. It can be check by two ways: internal validity (checks the design of the experiment) and external validity (checks if the conclusion is the real explanation of the phenomenon).
Now, in marine biologist experiment, he concluded the results only after one breeding season. This makes his results unreliable as it might have happened by chance.
Similarly, in cola experiment the taste was only checked by one candidate i.e. Karl. He might have problem in his taste buds. In addition, the temperature of cola can also affects its taste which is not taken care of in the experiment. Hence, it is not the valid experiment.
Similarly. Jeanette could use more plants for her experiment and Robert just followed only one instruction. He didn't perform any experiment.
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