A child should also be told that it’s OK to say they don’t know the answer to something or to correct the investigator if they say something wrong.

The evidence is “very clear,� the researchers wrote, that questions that result in a “yes� or “no� answer or questions that force a child to pick an answer should be avoided.

But in their review of 45 interviews from an unnamed Canadian police agency, the researchers found that there was little rapport building and an “over reliance� on closed or directive questions. In fact, open-ended questions — those that begin with “tell,� “explain,� or “describe� — were used only 7 per cent of the time.

“Interviewers are potentially narrowing the scope of their investigations by limiting the information they elicit from the child and by collecting information that is of questionable quality,� they wrote.

The Canadian Child Abuse Association recently started offering the country’s first voluntary certification program for forensic child interviewers. Investigators must complete a written exam, plus submit a recorded child interview for review by a team of experts.

Four members of the Calgary Police Service’s child-abuse unit have so far been certified, said Staff Sgt. Kelly Campbell, who heads the unit out of the Sheldon Kennedy Child Advocacy Centre.

Interviewing children can be challenging because they have narrower attention spans, but it is critical that investigators avoid the temptation to ask leading questions, she said.

“If you say, ‘Did he touch you in your private parts?� and he says, ‘Yeah,’ well, then you’re done because you’re suggesting this person has done something to them,� Campbell said.

You have to give the child the opportunity to “give their rendition of the facts.�

Australia is in the midst of developing a national training curriculum in child interviewing, said Martine Powell, a professor of forensic psychology at Deakin University in Melbourne. Hands-on training is critical, she said.

Sometimes, children are used in training; other times, actors mimicking the behaviours of children are used. Officers also watch videos or do “virtual interviews� using animated characters.

Powell said open-ended questioning should also be encouraged when trying to elicit confessions from suspects.

dquan@postmedia.com

Twitter.com/dougquan