Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Student difficulties with the probability distribution for measuring
  energy and position in quantum mechanics   We have been investigating the difficulties that students in upper-level
undergraduate courses have in determining the probability distribution for
measuring energy and position as a function of time when the initial wave
function is explicitly given. We administered written free-response and
multiple-choice questions to investigate these difficulties. We find that
students have common difficulties with these concepts. We discuss some of the
findings.

25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas