Step Seven: Non Response Bias

I am a little bit more excited to have non response bias than I should be. After all, any kind of bias is a bad thing, but I’m excited to know what it is. Non response bias occurs when not all of the people surveyed respond. So basically, I handed out twenty surveys and only got nineteen back. I honestly do not know how that happened because most people don’t even walk away before they taste both samples, scribble something down and hand me their completed survey. I’m not too worried about it. I doubt one survey would have made a big difference.

On to the results! Cookie A, which was made with pecans, was the winner by quite a margin. It was the one that seemed cakey. It was fun reading the comments on this batch of surveys because most of them were so positive. I had one that said, “Not great, nut also not vomit-inducing,” so they weren’t all positive, but most said things like, “Both are delicious!” The most common complaint was that the cookies were not sweet enough.

Cookie A (Pecans)
Mean= 4.316 Standard Deviation=.862 Proportion Who Prefer A: 19/19

Cookie B (Almonds)
Mean=3.211 Standard Deviation= 1.06 Proportion who Prefer B: 0/ 19

Non-Response Error: 1

Again, these results are not random, but just for fun, I did another significance test, and surprise, surprise, these results actually ARE statistically significant. The p-value is .0015 which means that I could reject the idea of the preferences being basically the same at a 1% level! That may not mean much to most people, but I’m pretty excited about that. It means that people actually had a strong enough preference for it to be reflected in the results!

Here’s the recipe for Cinnamon Pecan Cookies
(modified from this recipe: http://vegweb.com/index.php?topic=6391.0)

Ingredients: (at room temperature)
2 cups unbleached flour
2 tsps baking powder
½ tsp salt
1 tbs cinnamon
¾ cup chopped pecans, toasted
1 cup vegan sugar
¼ cup vegetable oil
¼ cup apple sauce
1 teaspoon vanilla
¼ cup water

Directions:
1. Preheat oven to 350 degrees. Mix flour, baking powder, salt, cinnamon, and pecans.
2. In a second mixing bowl, whisk together sugar, vegetable oil, and apple sauce. When it is fully mixed, add vanilla, and mix. Add water and mix thoroughly.
3. Form a well in the dry ingredients and add wet ingredients.
4. Spoon rounded tablespoons of dough onto baking sheet. Press each ball down a little in the center. The cookies do not spread very much.
5. Cook for 5 minutes, then rotate the pan, and cook for another 8 minutes. Take the cookies out even though they may not look ready, and allow them to cool on the pan.