Among my many private worries as a parent, I've wondered if I hover too much. New research on helicopter parents confirms it: I am one.

I have plenty of company. An estimated 40 percent to 60 percent of college parents qualify as helicopter parents, and they come from all socioeconomic groups, based on a thought-provoking study of 75 officials, professors and staff at 15 universities.

The study, which is drawing attention on campuses, moves the helicopter-parent debate onto new ground by identifying types of parental hovercraft, ranging from benign to pathological.

There's room to disagree on the boundaries of healthy parental involvement with college-age students, the focus of the research. Nevertheless, I found the typology a helpful lens for sizing up my parenting. If you're wondering where you stand, here are a few of the most distinct types:

■ The Blackhawk Parent: Among the most damaging types, this parent "comes in with guns blazing," demanding action, says Patricia Somers, an associate professor at the University of Texas, Austin, and lead author on the study. One problem, says Jim Settle, vice president, student affairs, at Shawnee State University, Portsmouth, Ohio, and a co-author, is that "they start at the president's office, regardless of the issue". Blackhawk parents set bad problem-solving examples and hamper their children's independence.

■ The Toxic Parent: These parents meddle in intrusive ways that imply the student is untrustworthy or ill-equipped. Parents at several schools, Dr. Somers says, obtained their children's log-on information, researched prospective roommates on Facebook, then masqueraded as their children online to request roommate assignments. One couple cited separately in the study installed a nanny-cam in their son's dorm room; the student was aware of the nanny-cam but didn't know Mom and Dad also planted an electronic transmitter in his car. When he strayed to a nearby city in his car, they withdrew him from college.

■ The Consumer Advocate: College officials tend to dislike these parents, who regard higher education as a consumer transaction and negotiate tirelessly for discounts. Educators say providing an education is more than that and doesn't always mean keeping the customer happy. But with the average total cost of a year in a private college topping $30,000, according to the College Board, I'm not sure parents have a choice.

Consumer advocates consider themselves "co-purchasers" entitled to all the same information and staff access as their children, researchers say. Many err in expecting a "warranty", the study says — a post-graduation job guarantee. But they also can serve as valuable models of effective consumer advocacy. Nancy Brown says she couldn't afford more than four years' college tuition for her daughter, and she doubts her daughter would have made it through that quickly without Ms Brown's involvement.

Her daughter's e-mail requests for her adviser's help registering for classes during a semester abroad were ignored; it took an e-mail from Ms Brown, of Kansas City, Missouri, to spark a response.

■ The Safety Expert: These anxious parents, more numerous since the Virginia Tech shootings, want to know about security plans and lockdown times, Dr. Somers says.

Dr. Settle says he expects parents to ask about emergency plans, but some cross the line by demanding copies of fire-inspection records and confidential emergency-operations manuals. While such parents can be overprotective, they also, with some restraint, can teach valuable safety lessons.

■ The Traffic and Rescue Helicopters: These terms, coined by an official at Saint Joseph's University, Philadelphia, cover parenting types regarded as benign.

The Traffic Helicopter gives advice and guidance but leaves decision-making up to the student. The Rescue Helicopter — my category — rushes in to help with supplies and support in a crisis.

Admittedly, I may be on the phone with my daughter, a sophomore, too much (several times a week).

Last winter, I hopped a plane to spend a weekend with her during a low time. To me, the complexity of today's campus life warrants extra parental support. Only time will tell whether my methods are wise.