SHOWING MY DATA

[recee680]

Hi,
I am a parent of a fourth grader, his project is on how permanent are pemanent markers. I have done the experiment what I need to know is how do I show his data, what type of graphs would I use. I took for swatches of cloth marked them all with a red marker, used four different solvents to see which one would make the marker ink lighter. Only one of the solvents really worked, nail polish remover, how can I show the data?

Concerned Parent,
Blondyne

[Craig_Bridge]

You are probably going to hate to have your question answered by questions, but here goes:

What was his hypothesis? The type of data you collect needs to prove or disprove the hypothesis so knowing the hypothesis is important to designing the experiment.

In his experimental design, did you come up with a way to "quantify" the results, in other words reduce it to a number? Based on your question, I suspect not.

If the hypothesis was something like "red permanent magic markers won't permanently mark <the name of the type of fabric that you tested> in the presence of <list of solvents>", then you might be able to quantify the effectiveness of some solvent via digital photography if you have an appropriate digital camera (one that you can manually set the exposure via aperature and shutter speed that has a histogram feature or if you have some image viewing software that will do it on the raw image).

If your fabric was green or blue you could setup a standardized lighting condition (otherwise dark room with a light at a fixed distance from the fabric) and take a digital picture of the unmarked fabric filling the entire frame and looking at the histogram of the RGB channels. Hopefully, you get a very low value on the red channel because of your choice of fabric. If you used white fabric, then you will have a higher baseline and the measurements will be less sensitive. You then take a picture of each marked sample and the red channel histogram is hopefully significantly higher than the baseline and the other channels are close to the same as the unmarked sample. For this picture, you would want to include all of the marked area and as little of the surrounding area as possible to be as sensitive to the marking area as possible. This red channel reading is your marked sample topline. You then treat each marked sample and take a picture of the result and use the relative difference between the baseline and topline red channel results as a measure of how well the magic marker did or how well the solvent did depending on the exact wording of the hypothesis (what you are trying to prove or disprove).

Single sample testing really isn't conclusive, so you probably need to utilize multiple samples. Depending on the exact wording of the hypothesis, a single treatement of with a solvent may not be sufficient. You may need to use multiple applications and check for "bleeding" of the magic marker dye into previously unmarked areas. Depending on the exact wording of the hypothesis, you might also want to see if there is solvent transfer by using a clean piece of the same cloth under the marked piece as you work the solvent through the cloth. You might also look at what happens to the back side of the cloth as well.

From what little you gave me to go on, I suspect that this experiment is not one that can be answered with a simple absolute YES or NO. You did see some evidence of something occuring with one of your solvents. Yes, no, maybe, almost no, or almost yes is a result that has to be quantified to be scientifically meaningful.

Often people start out doing experiments without thinking them through sufficiently and refining them into something that actually involves utilizing a scientific method that will produce measureable results.

What does this mean to the experiment? If you have the equipment (digital camera that is capable of providing separate RGB information with a fixed exposure), you could redo the experiment after evaluating my proposed measurement methods. You could alter the hypothesis to something that can be answered YES / NO. A red permanent magic marker can/cannot be completely removed from <fabric type> with <list of solvents>. Here the situation is if you can still see any evidence of the marker, it was not completely removed. If you go this route, a graph won't be possible and the best way to show the results is a table. Please note that it is intellectually dishonest to alter the hypothesis to fit the data; however, the teacher might allow the original hypothesis to be reworded to make it measureable with a yes/no test without changing the "position" based on what your experiment showed. In other words if you started with something saying that permanent markers are permanent your reworded one needs to take that same stance. If your original hypothesis was the converse, your reworded one needs to take that stance.

[SRGT BUBBLES]

Hello,

I have come up with a simple approach towards representing your data...
(I would recommend that you serch my other posts for a similar response)
I believe that the simplest way to show information like this would be to use a bar graph.
The reason why is because bar graphs can be greatly modified to fit your needs.
You can assign different colors to different solvents and these can be "stacked" along the y-axis.
The x-axis would be your time (possibly in minutes).
If you need a clearer description please feel free to leave me a response, best of luck!