Best practices for A/B testing a form

Level 1

Best practices for A/B testing a form

Hi team,

We are currently running PPC ads that drive users to Marketo landing pages with a form to download content. Form fields are Name, Email, Role, and Company (all are required). There are multiple landing pages for different pieces of content, and I use the same form across all of the LPs and use the Referrer constraint in my smart campaigns to make sure the right piece of content gets delivered. I would like to run an A/B test on the form by adding Phone as a required field. I hypothesize that people are less likely to submit the form if Phone is required (or they'll put in false data). I have only ever ran A/B tests in emails, never on a landing page or form. What is the most practical way to set up this test? Should I use the Test Group feature in Marketo, or should I run the test using our testing tool Google Optimize? I'm also assuming that regardless of which one I use, I'll have to create B versions by cloning all of the landing pages and the form and add the phone field. Is this the easiest/best way to do this?

Thanks in advance for your help,