There is no better, only trade offs. Here are the merits of each as an interview technique (I don't address the appropriateness of their respective sampling frames).
In-person, you have the opportunity to probe further based on respondent reactions. You may also achieve a better cooperation rate (meaning the respondent engages with and finishes the surve... (more)
There are several ways to do this, depending on the size of your customer base and line of business. I'll write about three ways to do this, although none of the methods are mutually exclusive.
Small Customer Base
At checkout, ask your customers to provide their email addresses as part of a loyalty program. When you have a substantive list built up, you... (more)
Gartner and Forrester frequently rely on both online and offline B2B surveys to build their reports. Most frequently, data collection is done through another provider of data collection services like ResearchNow, SSI, Toluna, uSamp, Authentic Response, and Discovery Research.
When talking to Forrester/Gartner about the reliability of their research, here... (more)