Before revision:  Problem 2 \underline{\textit{\textbf{ is that there are many unusual discontinuities in the saccade trajectories from the Lund University dataset that make it a very poor choice for the construction of an automatic classification method.
After revision:  Problem 2 \underline{\textit{\textbf{Problem 2 is that there are many unusual discontinuities in the saccade trajectories from the Lund University dataset that make it a very poor choice for the construction of an automatic classification method.