A decade after age-based ratings for tv were introduced, some parents don't think that such ratings are accurate.
The American Academy of Paediatrics and some other groups have come out in favour of a universal ratings system for all forms of media, and the study, published in Paediatrics, said their results suggested parents might support such a move.
"Parents desire ratings for many types of media, but they do not think the existing ratings accurately provide the information they want," wrote Douglas Gentile.
"They would prefer ratings to provide detailed content information... They do not, however, agree on the ages for which different content aspects are appropriate."
Currently, the different US media ratings systems have their own age-based categories.
TV shows come with ratings such as "TV-14," which indicates "parents strongly cautioned," and "TV-G," or suitable for a "general" audience. There is also some content description, such as "V" for violence and "S" for sexual situations.
Video games go further, with packaging that provides age ratings and a bigger variety of content descriptors, such as "blood and gore" and "strong language."
The study looked at surveys of nearly 2,300 US parents conducted online. Only 5% thought they were always accurate, while between 41 to 46% thought they were at least "usually accurate."
Some past studies have found that parents often do not pay much attention to media ratings systems. Gentile said the current findings suggest a reason: many don't think they're accurate or useful.
In one of the surveys his team used, parents were given a list of specific types of TV
content with fairly detailed content. "Violence" was broken down into 10 situations, ranging from "scary" images to graphic violence and sexual crimes.
The researchers found that for about half of the content descriptions presented to parents, a majority of parents agreed they would keep a child from viewing it.
When parents were asked if they would like a universal ratings system, a little more than half said they would at least "somewhat support it."
But other experts disagreed, noting that other polls have suggested that most parents are satisfied with the ratings system
and that the results did not suggest a strong desire or mandate for change.
One flaw in the current study is that it is based on surveys done several years ago - and online at that, said Christopher Ferguson from Texas A&M International University.
"When you invite people to take an online survey, you're likely to draw the people who are upset about something," added Ferguson, who has studied media violence and children's aggression - and found no link.
With the move towards media convergence, under which people will get their TV shows, movies and videos on one device, Gentile said it is time to work on a universal ratings system.
But Ferguson thinks a universal system is unworkable and that parents who want more information than the current ratings system will have to be proactive and seek it out themselves.
What are your thoughts on the age-based media rating system?