Boro's slide continued with a fifth straight away loss as they went down 2-0 to Preston at Deepdale.
"We've learned so much about ourselves in this difficult period, stretching back three or four wins in 15 games," said Smith.
"They realise their display is nowhere what they're capable of, too many players have fallen short of what they're about.
"The big factor for us has been consistency, we've been too up and down both individually and team displays.
"I can set targets for them but the players have got to challenge themselves every game in the run-in."
Smith added: "We started poorly. Preston showed more edge, more determination and in the opening 20 minutes there were too many Preston players that dominated ours. The game was well and truly won for Preston within 30 minutes."