Placing snippet of code in <head> of all pages.
We have two landing pages setup within Optimizly.com with 2 final varient experiments and the original. So three variations in total. The developer (after being instructed not too) installed the snippet code on ALL of the pages within website. Placed within the <head> section. All experiments are within one domain.
How will this affect my reporting? Is there a negative affect or invalid data? What errors should I expect?
As it turns out, it's good to have the Optimizely snippet on every page of your site. If you want to limit the experiment to specific URLs, you should use the URL Targeting feature to specify where you want the experiment to run.
How this affects your current experiment is difficult to say without knowing what the variations do and what goals they're tracking.