Sanderson will report to Liz McMahon, BMRB's director of media and access omnibus surveys, where she will focus on developing new services for BMRB Media and Omnibus.
Previously Sanderson ran the ad hoc media research unit at Ipsos Mori, conducting marketing research across a range of sectors for the company's Research International and Mori divisions.
Helen Rice joins BMRB Stakeholder as a director, where she will help to expand the company's employee research technology.
Rice worked at Ipsos Mori for five years as head of public-sector employee and HR research, and will now manage BMRB Stakeholder, a 16-strong team that works on improving clients' business performance through the measurement of customer loyalty.
She replaces Lynne McClymont, who will now focus on new product development and client services.
McMahon said: "[Sarah] will bring new thinking and skills to an already successful team. I'm especially excited by her knowledge of researching media brands which is a major preoccupation for many of our media owner and agency clients in today's competitive market."
Richard Asquith, managing director of BMRB, added: "[Helen] will be able to exploit the synergies between stakeholder and public sector research, two areas where BMRB has always had strong presence."
The appointments follow a spate of recent additions to Ipsos Mori's senior management team, which have included Ian Bramley as global account director and Stuart Grant as associate director to work in the company's specialist entertainment advertising sector.
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