CHICAGO - What's so unusual about a baby fascinated with spinning a cup, or a toddler flapping his hands, or a preschooler walking on her toes?

Parents and even doctors sometimes miss these red flags for autism, but a new online video "glossary" makes them startlingly clear. A new website offers dozens of video clips of autistic kids contrasted with unaffected children's behaviour. Some of the side-by-side differences can make you gasp. Others are more subtle.

The free site, debuting Monday, also defines and depicts "stimming," "echolalia" and other confusing-sounding terms that describe autistic behaviour. Stimming refers to repetitive, self-stimulating or soothing behaviour including hand-flapping and rocking that autistic children sometimes do in reaction to light, sounds or excitement. Echolalia is echoing or repeating someone else's words or phrases, sometimes out of context.

The new site is sponsored by two nonprofit advocacy groups: Autism Speaks and First Signs. They hope the site will promote early diagnosis and treatment, which can help young children with autism lead more normal lives.

Pediatrician Dr. Michael Wasserman cautioned that the site might lead some parents to needlessly fret about normal behaviour variations, and said they shouldn't use it to try to diagnose their own kids.

"Just as there's a spectrum in autism... there's a spectrum in normal development," said Wasserman, with Ochsner Medical Center in New Orleans. "Children don't necessarily develop in a straight line."

But Amy Wetherby, a Florida State University professor of communications disorders who helped create the site, noted that sometimes "parents are the first to be concerned and the doctors aren't necessarily worried. This will help give them terms to take to the doctor and say, 'I'm worried about it."

And while the children shown in the "Red Flags" video clips on the site have been diagnosed with some form of autism, the sponsors note that not all children who behave this way have something wrong. In fact, the behaviours in some of the short video clips - when viewed individually - look fairly normal.

The important thing is to seek medical help if a child does exhibit persistent unusual behaviour, to either rule out autism or get an early diagnosis, said Alison Singer of Autism Speaks.

Added Wetherby, "We now know that one out of 150 children has autism, or one out of 94 boys. It's not a rare disability. We also know that early intervention is critical."

The site was to be available to the public starting Monday on the Autism Speaks website http://www.autismspeaks.org.

Several autism specialists who reviewed it at the request of The Associated Press called it an unusually helpful tool for parents and doctors.

"The moving pictures speak a million words," said Dr. Edwin Cook, an autism researcher and educator at the University of Illinois at Chicago.

"Not only do I see this as useful for the general public and for parents who might be wondering ... but I will frankly be using it for education" and training, Cook said. He has received research funding from Autism Speaks but has no connection to the new site.

Stefanie Voss of Tallahassee, Fla., said it will be a great tool "for parents who are in the situation that I was in three years ago, which is, 'I'm not sure if something's wrong with my child."'

She said she asked her pediatrician about her son Nicholas when he was 14 months old and was told he didn't show "the classic signs" of autism.

"He did smile and have eye contact, but what I've learned since is those aren't the only red flags," Voss said.

Nicholas didn't point, wave, or demonstrate any other nonverbal communication. He'd also spend hours opening and closing cabinet doors or spinning plastic bowls on the floor.

She eventually took him to Florida State where he was diagnosed at age 17 months and intervention began. Nicholas is featured in a video clip on the site.

With speech lessons, physical therapy and behaviour training several hours daily, he's now affectionate, social, talking, walking and in preschool.

"It shows you that all your hard work and early intervention pays off," Voss said.

Dr. Karen Ballaban-Gil, a pediatric neurology specialist at Montefiore Medical Center in New York, said the site "will be doing a real service."

The site will eventually feature a section on autism treatments and Ballaban-Gill said the only scientifically sound ones are intensive behaviour training. Others, including special diets, are unproven and should not be included, she said.

Singer said there is no decision yet on which treatments will be added to the site.