Goals either side of half time by Gary Hooper and Leroy Fer saw Norwich come away from The Hawthorns triumphant, and Clarke has said that it was his players' lack of composure in front of goal which cost them.
"In the game we certainly had enough possession," Clarke told BBC Radio 5 Live. "We created enough, but we didn't score the goal.
"We conceded a disappointing goal early in the game, which always makes it difficult, but we tried to get back in and play our football. The fact of the matter is we should have got ourselves level early on in the second half and then we could have gone on to win the game.
"Eventually the second goal was a consequence of us trying to get something out of the game."
The result leaves West Brom in 15th place in the Premier League, just two points above the drop zone.