Dishwasher Soap Experiment Part 2 - DOE

First, some news from the TDE:
I have added yet another part time job to my collection. I'm now a substitute teacher for the local schools. I am going to do my best to keep to my schedule of blog posts on Wednesdays, but if I get called in to teach during the day (on top of teaching tap at night) on Wednesday, it sometimes will not happen. That is what happened this week. School ends at the end of May so we should be back to a regular Wednesday schedule starting in June.* Sorry for missing Wed this week and I apologize in advance for future late posts.

*Note: The TDE will be on vacation more often than not in June and internet conditions of each location are unknown. I will do my best to post on time and when unable I will post as soon as possible after finding internet. 

Now, on to the dishwasher DOE!

I spent the past few weeks pondering this in the back of my head. Every time I ran our tiny little dishwasher I considered how to make the experiment as controlled as possible. Based on my experiences of what is typically hard to clean and what is most annoying to me, I put together a plan for how to run this experiment. The DOE is a little boring because I am specifically testing type of dishwasher soap. So, dishwasher soap type is the only variable that I am changing. Everything else is staying the same and acting as a control to understand the performance of each type of dishwasher soap. A true DOE would generally involve changing multiple of the variables to discover the best conditions for the getting the cleanest dishes. Once I've got results for which type of soap is best I may play with some of the other conditions in follow up experiments. For now, however, here's my plan for the initial experiment:

*If more than 4 dishes with caked on food, will pre-wash only caked on food on additional dishes.

It's too small here, in order to fit on the page, but you can click on the pic to make it bigger. You can see that I'm keeping everything the same except for type of dishwasher soap. I'll be controlling the number of certain types of dirty dishes as well as density of the dishes and silverware. This should give a fairly controlled situation that will allow me to test the performance of each type of soap. I will reveal the actual brands/type of soap once the experiment is complete.

This is a good time to clarify that our dishwasher is a tiny countertop dishwasher. It is maybe 1/4 the size of a standard dishwasher.... maybe not even that big. So, that explains why I am only using a 1/2 tablespoon of soap (the size of the soap tray in the dishwasher.) It also explains why I'm only putting 3 pieces of silverware in each slot as 4 per slot is the max I typically put in it. 

Below is the table I will use to collect results. I've added one more result type as I've noticed that my coffee cups don't always get clean.

My hope is that I can run a load of dishes for the experiment once per day. There may be times that I need to wait to accumulate more dishes or the right kind of dirty dishes so I may need to skip some days. I'm guessing I'll also have to run a few loads of non-experiment dishes in order to keep up with the pile of dirty dishes. And, in order for things to be as controlled as possible I may need to just wait for the right conditions to occur (such as # and age of PB spoons.) So, best case scenario this experiment will take 2 weeks. However, I expect that it will actually take quite a bit longer than that. Hopefully I will finish before June because, as previously mentioned, we will not be home much in June. I will post the results whenever the initial experiment is complete. 

So there it is. Thats all for this week. Feel free to share your thoughts on this in the comments. Am I missing anything important?