Menendez International has relocated its offices to 8931 SW 85th Street, Miami, FL 33173. Telephone 305-598-2829. Fax 305-598-4899.

A new custom marketing research firm, Research Plus, has opened at 1821 Walden Office Square, Schaumburg, IL 60195. Herb Hupfer and Carolyn Heimbach are the principals.

Jill L. Siegel is the new owner and president of Olchak Market Research. She has purchased the 20 year-old field service from its founder, Rhoda Olchak, who will remain as a consultant to the company. The company is located in the greater Washington, D.C. area.

Charles Schwartz, a demographer specializing in marketing research and information systems, has formed Demometrika. The company performs demographic and statistical analysis of market research data ranging from market demographics to consumer preference mapping. The company's address is P.O. Box 66689, Los Angeles, CA 90066.

MarketVision Research, Inc. has opened a new division, MarketVision Consulting, which will have offices in Cincinnati, and Charlotte, NC. The firm's primary focus will be the implementation of customer satisfaction research programs. Ronald W. Miller has been named president. He will work out of the Charlotte office.

ACG Research Solutions has opened a new focus group facility in Clayton, MO. ACG is located at 120 South Central, Suite 1750, St. Louis, MO 63105.

Erdos & Morgan, Inc. and Marketing Projects Group (MPG) have merged to form Erdos & Morgan/MPG. The company is headquartered at 116 East 27th St., New York, NY 10016.

Randy Thaman and Dave Disher, both senior vice presidents of Marketing Research Services, Inc., have contracted to purchase the company from its founder Edward D. Horgan, for an undisclosed amount.