The Robins went in front after just 13 minutes courtesy of Scott Wagstaff only for Nahki Wells to draw the Bantams level.
Jay Emmanuel-Thomas then slotted home left-footed from a Sam Baldock cross after 58 minutes to restore the hosts' advantage, but Rory McArdle had the final say as the game entered the closing stages.
O'Driscoll said: "It will take time to bed them all in and there was a lot of good in how we started the game and the way the players went about their business.
"We gave away two very poor goals and were guilty of surrendering possession too easily at times.
"But Jay Emmanuel-Thomas showed what a threat he will be in this league and if we can get him a bit fitter he will be an even greater force.
"There is a lot to work on, but I could see things to build upon and we will get better."
Asked for the latest on winger Albert Adomah's proposed £1million move to Middlesbrough, O'Driscoll said: "It has been on and off so many times I've lost count. I didn't feel it was fair on the lad to play him."