# Thread: Poll "Normalization"--How to Filter?

1. ## Poll "Normalization"--How to Filter?

Example--A blind, online poll. Suppose the question asked is something like "Do you trust left-handed people?" Assume that no left-handed people would say "no".

The poll reports that 10% answered no. But if 15% of those polled are lefties, how would their "yes" votes be filtered out--in order to see what righties think?

It can't be as simple as subtracting them out, because 10 minus 15 is -5. Hopefully this can have a simple answer as I never took any math higher than Alg. 2, and had to take it a few times to pass.

2. ## Re: Poll "Normalization"--How to Filter?

Assume that no left-handed people would say "no".
As you have pointed out...15% left handed people took the survey but you only had 10% negative responses, so this assumption must be incorrect.

Setting that aside,
If you know for every response whether the person is leftie or not, you can look at your data seperately for each group (eg, find what proportion of righties would trust a leftie).

3. ## Re: Poll "Normalization"--How to Filter?

Originally Posted by SpringFan25
As you have pointed out...15% left handed people took the survey but you only had 10% negative responses, so this assumption must be incorrect.

Setting that aside,
If you know for every response whether the person is leftie or not, you can look at your data seperately for each group (eg, find what proportion of righties would trust a leftie).
Uh, do not understand your reply. We assume that ALL lefties (15% of those polled) said "Yes" to the trust question, and 10% of *everyone* polled said "no". Question is, what % of righties (85% of those polled) said "no".

We'll ignore the ambidexes. here.

4. ## Re: Poll "Normalization"--How to Filter?

ignore my first post.

if:
90% said yes overall
15% are lefties and said yes
85% are righties

Then the total number of "yes" votes cast by lefties is: $\displaystyle 90\% - 15\%$

and sot he proportion of righties voting yes is $\displaystyle \frac{90\%-15\%}{85\%} = 88.235\%$

5. ## Re: Poll "Normalization"--How to Filter?

Thanks! I thought there had to be a simple way to do this.

Originally Posted by SpringFan25
ignore my first post.

if:
90% said yes overall
15% are lefties and said yes
85% are righties

Then the total number of "yes" votes cast by lefties is: $\displaystyle 90\% - 15\%$

and sot he proportion of righties voting yes is $\displaystyle \frac{90\%-15\%}{85\%} = 88.235\%$