Apple has hired research firm Advanis to conduct a survey that may help determine the existence of the hotly debated iPod 'halo effect,' a term defining Windows users who purchase Mac computers following exposure to the company's iPod digital media player. The survey asks various questions about future PC purchase intentions, according to ITWire, prompting whether participants use iTunes on a Mac or a Windows system. Further questions inquire as to whether users have purchased a new computer since since shopping on iTunes, and whether they plan to purchase a new computer within the next year. The online survey of existing iTunes Music Store users also asks expected questions about music consumption, iTunes client experience, preferred music genre, and digital music player preference.