1.7 Designing a Well Constructed Experiment

When you want to test something new out, you can create a mini experiment. The time and energy may set some limits on how much or how elaborately you can test something.

For crocheters (& knitters too, right?), isn't this a "swatch" - a small piece of "fabric" created using the needles and yarn that you want to use, making a certain number of stitches, so you can test to find out how big of object the pattern will create. To change the results of this test, you either, a) change the amount of tension you put in the piece, b) change the yarn, or c) change the needles. (See an article by Craftzine.com blog for a little bit more on this)

For some experiments you may hate the original test swatch, and start over from scratch with all three new things. But if you "kind of like it" to create a well constructed experiment, you want to change only one thing. You create one swatch with different needles but the same yarn, a third swatch with different yarn, but the same needles, and compare. This way you know the difference the needles make, and what difference the yarn makes - but you have to make 3 swatches for this.

For quilting, if you would want to test a thread, you would divide the same batting up into small pieces - one piece for each thread you want to test, and have a top and a backing fabric the same for each test piece, then stitch similar designs with similar stitch length (use a walking foot on all test patterns and do criss crosses on each test piece for example). You stitch with each thread onto your quilt test pattern, and decide what you like best.

Keeping things the same in science is a controlled variable. The batting, the top and backing fabric, the stitch length are all controlled variables in the example above. It makes for good science to have a lot of controlled variables, and then only change one thing. Otherwise, if you change the batting, backing fabric, stitch length, and thread, you get a different result, but you don't know what caused it. This will give you a well constructed experiment.

Getting a completely different result because of changing all the variables isn't always bad. But it will not help you figure out differences in specific items easily. From a scientific approach, the better the experiment, the better knowledge you gain as a result, but maybe most of the results are not pretty, so more results could = more failures. (which isn't always bad in crafting & experiments).

Remember that a failed experiment is still a good experiment.

I am trying to figure out if my applique quilt will work good for embroidery. I made a sample block of the same applique fabrics, patterns, technique, backing fabric, applique thread, and now I am making my only major difference the embroidery. Well the overall pattern isn't the same exactly, but it will give me an idea - and there is no way I'm making more than one of the original quilt tops right now. I am trying to set up a well constructed experiment for myself that will give me enough information to make a decision on the original.