"We have been asking our guys to revisit the five key areas. We think they started with really good intentions last year, but the foot has come off the throat, especially at the tackle - the tackler rolling away and the entry - and especially the offside line in close," O'Brien said.
In a presentation paper, O'Brien listed the five key areas:
* The breakdown - tackler must roll away and assist tackler must release, while arriving players must come through the gate.
* The scrum - slow sequence of four calls, the loosehead must have his head and shoulders above hips and the tighthead must bind on the body of his opponent, not the arm.
* Offsides - strict policing of offside players close to the breakdown and players in front of kicker must remain stationary until put onside.
* Mauls - the ball-carrier must be available to be tackled by the defending team.
Foul play - high tackles, grabbing and twisting of the head and tip tackles to be emphasised, with referees to start at red and work backwards.
"The 20 teams at the World Cup all received the same presentation and they have bought into it. What we've got to do as referees is make sure we implement them.
"While the refs have done some of them very well, we think as an overall picture ... we need to reassess them," O'Brien said.
Former test referee Kelvin Deaker, who joins the Herald as a columnist during the World Cup, said he had real fears around the officiating of scrums where, he said, resets would not be tolerated.
"This may prove a lottery at times depending on perceived scrum dominance and position on the field. An early engagement or hand on the ground is an easy way out for the ref no matter what the circumstances," he said.
Deaker also said he did not enjoy the leniency given to the attacking team, describing it as a pet hate.
"A pet hate of mine at the moment is the lenience given to the ball-carrying team at the tackle whilst the defenders are made to stand back and watch."
All the pool game appointments have been made and knock-out selections will be based on form.
"We don't go out to pull rabbits out of the hat," he said.
"We just want the boys to get the clear and obvious and be accurate, that's all."
O'Brien is meeting the coaches again on Wednesday.