Speaking to BBC Radio Northampton after parting company with a manager he said he had 'wanted to succeed', the Cobblers chairman stated: "I did not see enough signs that we were improving as a side.
"Ian had put together a decent squad, and in a way that made our league position all the more unacceptable."
Cardoza was very upbeat however at the direction the club as a whole is going in and the opportunity available to whoever succeeds Sampson.
He added: "I think this will be an attractive job.
"We were one of very few clubs in League One or League One to spend money in January and we have some talented players under contract for next season with plenty of scope for any additions to be made in the summer.
"This appointment will be one of the biggest decisions since I have been here, we need to get things as right on the field as we are off it."