  This paper reports on an investigation into the correlations between
students' understandings of introductory astronomy concepts and the correctness
and coherency of their written responses to targeted Lecture-Tutorial
questions. We assessed the correctness and coherency of responses from 454
college-level, general education, introductory astronomy students enrolled in
courses taught in the spring of 2010, 2011, and 2012. We hypothesized that
students who consistently provided responses with high levels of correctness
and coherency would outperform students who did not on multiple measures of
astronomy content knowledge. We compared students' correctness and coherency
scores to their normalized gains on the Light and Spectroscopy Concept
Inventory (LSCI) and to their scores on closely-related exam items. Our
analysis revealed that no significant correlations exist between students'
correctness and coherency scores and their LSCI gain scores or exam item
scores. However, the participant group in our study did achieve high scores on
the LSCI and on closely-related exam items. We hypothesized that these
differences are due to the discussions that take place between students which
suggests that instructors who teach with active engagement instructional
strategies should focus their implementation on ensuring that their students
fully engage in the richest possible discourse.
