Which one is the independent variable and which one is the dependent variable?
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jordanmaness
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Which one is the independent variable and which one is the dependent variable?
https://www.sciencebuddies.org/science- ... #learnmore >>> this is one of the projects on your website and i’m wondering what the independent variable is and what the dependent variable is. THANK YOU!!! Please help!!!
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SciB
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- Project Due Date: n/a
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Re: Which one is the independent variable and which one is the dependent variable?
Hi Jordan,
The project asks the question--What is the effect of changing the color of light on the chlorophyll pigment in a leaf? So, your independent variable--what you manipulate in the experiment to produce different conditions--is the color of the light which you control by using the different colored plastic films. The dependent variable--what you measure in the experiment--is the appearance of the leaf directly under the plastic film.
I don't like experiments that are not quantitative--that do not give you a numerical measurement that you can use to do statistics on your data. The 'appearance' of a leaf is going to depend on the person doing the observation and is subjective. To get a quantitative read-out there is a program that you can use called ImageJ (https://imagej.nih.gov/ij/) that allows you to measure the color density of a jpeg image and gives you a number value. All you have to do is take photos of the leaf surface after you remove the plastic films and download the image files into your PC. Download the program and open the image file in ImageJ and use the tools to define an area of the image to analyze, then do the same measurement on each photo. Also be sure that you take the photos using the same distance from camera lens to leaf and the exact same lighting conditions each time.
If you decide you want to try ImageJ let me know and I can help if you have any problems.
Sybee
The project asks the question--What is the effect of changing the color of light on the chlorophyll pigment in a leaf? So, your independent variable--what you manipulate in the experiment to produce different conditions--is the color of the light which you control by using the different colored plastic films. The dependent variable--what you measure in the experiment--is the appearance of the leaf directly under the plastic film.
I don't like experiments that are not quantitative--that do not give you a numerical measurement that you can use to do statistics on your data. The 'appearance' of a leaf is going to depend on the person doing the observation and is subjective. To get a quantitative read-out there is a program that you can use called ImageJ (https://imagej.nih.gov/ij/) that allows you to measure the color density of a jpeg image and gives you a number value. All you have to do is take photos of the leaf surface after you remove the plastic films and download the image files into your PC. Download the program and open the image file in ImageJ and use the tools to define an area of the image to analyze, then do the same measurement on each photo. Also be sure that you take the photos using the same distance from camera lens to leaf and the exact same lighting conditions each time.
If you decide you want to try ImageJ let me know and I can help if you have any problems.
Sybee
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jordanmaness
- Posts: 2
- Joined: Thu Nov 02, 2017 5:12 pm
- Occupation: Student
Help on a quantitative measurement.
https://www.sciencebuddies.org/science- ... #learnmore
Hi! I’m doing this project for my Biology IRP, and my teacher said it was a good project, as long as i can have a quantitative measurement. Do you have any ideas on what i can measure in numbered with this project? It would help a lot! Thanks!
Moderator note: This question seems related to your previous post, so I'm merging this with the previous one. That way the expert who helped you can continue to follow-up with you. Thanks!
Hi! I’m doing this project for my Biology IRP, and my teacher said it was a good project, as long as i can have a quantitative measurement. Do you have any ideas on what i can measure in numbered with this project? It would help a lot! Thanks!
Moderator note: This question seems related to your previous post, so I'm merging this with the previous one. That way the expert who helped you can continue to follow-up with you. Thanks!
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SciB
- Expert
- Posts: 2068
- Joined: Fri Feb 01, 2013 7:00 am
- Occupation: Retired molecular biologist, university researcher and teacher
- Project Question: I wish to join Scibuddies to be able to help students achieve the best science project possible and to understand the science behind it.
- Project Due Date: n/a
- Project Status: Not applicable
Re: Which one is the independent variable and which one is the dependent variable?
Hi,
Please see my previous post about using ImageJ to quantitate chlorophyll content in photos of leaves. That should give your project's dependent variable the number value it needs.
There are several tutorials on Youtube that show you how to use ImageJ. Here's an example, but there are lots more: https://www.youtube.com/watch?v=_zgvo6GBdX8
If you have more questions, please post again on this same thread.
Good luck,
Sybee
Please see my previous post about using ImageJ to quantitate chlorophyll content in photos of leaves. That should give your project's dependent variable the number value it needs.
There are several tutorials on Youtube that show you how to use ImageJ. Here's an example, but there are lots more: https://www.youtube.com/watch?v=_zgvo6GBdX8
If you have more questions, please post again on this same thread.
Good luck,
Sybee