One of the units in the relatively new high school CS curriculum which is being implemented in Israel is a theoretical unit on computational models. It includes deterministic and non-deterministic finite automata, regular and non-regular languages, closure properties of regular languages, pushdown automata, closure properties of context free languages, Turing machines, the Church-Turing thesis and the halting problem. This paper focuses on part of a study we conducted dealing with the achievements of high school students studying this unit. Specifically, this paper compares the achievements of students on the technical parts of this unit vs. its theoretical parts. We also examine the correlation between achievements of students studying the Computational Models unit, and two other factors: The students' previous computer-related background (not necessarily computer science) and the level on which they studied mathematics.