4,939 research outputs found
Research-based assessment of students' beliefs about experimental physics: When is gender a factor?
The existence of gender differences in student performance on conceptual
assessments and their responses to attitudinal assessments has been repeatedly
demonstrated. This difference is often present in students' preinstruction
responses and persists in their postinstruction responses. However, one area in
which the presence of gender differences has not been extensively explored is
undergraduate laboratory courses. For example, one of the few laboratory
focused research-based assessments, the Colorado Learning Attitudes about
Science Survey for Experimental Physics (E-CLASS), has not been tested for the
existence of gender differences in students' responses. Here, we utilize a
national data set of responses to the E-CLASS to determine if they demonstrate
significant gender differences. We also investigate how these differences vary
along multiple student and course demographic slices, including course level
(first-year vs.\ beyond-first-year) and major (physics vs.\ non-physics). We
observe a gender gap in pre- and postinstruction E-CLASS scores in the
aggregate data both for the overall score and for most items individually.
However, for some subpopulations (e.g., beyond-first-year students) the size or
even existence of the gender gap depends on another dimension (e.g., student
major). We also find that for all groups the gap in postinstruction scores
vanishes or is greatly reduced when controlling for preinstruction scores,
course level, and student major.Comment: 11 pages, 3 figures, accepted to Phys. Rev. - PE
Improvement or selection? A longitudinal analysis of students' views about experimental physics in their lab courses
Laboratory courses represent a unique and potentially important component of
the undergraduate physics curriculum, which can be designed to allow students
to authentically engage with the process of experimental physics. Among other
possible benefits, participation in these courses throughout the undergraduate
physics curriculum presents an opportunity to develop students' understanding
of the nature and importance of experimental physics within the discipline as a
whole. Here, we present and compare both a longitudinal and pseudo-longitudinal
analysis of students' responses to a research-based assessment targeting
students' views about experimental physics -- the Colorado Learning Attitudes
about Science Survey for Experimental Physics (E-CLASS) -- across multiple,
required lab courses at a single institution. We find that, while
pseudo-longitudinal averages showed increases in students' E-CLASS scores in
each consecutive course, analysis of longitudinal data indicates that this
increase was not driven by a cumulative impact of laboratory instruction.
Rather, the increase was driven by a selection effect in which students who
persisted into higher-level lab courses already had more expert-like beliefs,
attitudes, and expectations than their peers when they started the lower-level
courses.Comment: 6 pages, 1 figure, submitted as a short paper to Phys. Rev. PE
Students' views about the nature of experimental physics
The physics community explores and explains the physical world through a
blend of theoretical and experimental studies. The future of physics as a
discipline depends on training of students in both the theoretical and
experimental aspects of the field. However, while student learning within
lecture courses has been the subject of extensive research, lab courses remain
relatively under-studied. In particular, there is little, if any, data
available that addresses the effectiveness of physics lab courses at
encouraging students to recognize the nature and importance of experimental
physics within the discipline as a whole. To address this gap, we present the
first large-scale, national study ( and
) of undergraduate physics lab courses through analysis of
students' responses to a research-validated assessment designed to investigate
students' beliefs about the nature of experimental physics. We find that
students often enter and leave physics lab courses with ideas about
experimental physics as practiced in their courses that are inconsistent with
the views of practicing experimental physicists, and this trend holds at both
the introductory and upper-division levels. Despite this inconsistency, we find
that both introductory and upper-division students are able to accurately
predict the expert-like response even in cases where their views about
experimentation in their lab courses disagree. These finding have implications
for the recruitment, retention, and adequate preparation of students in
physics.Comment: 10 pages, 2 figures, Accepted to Phys. Rev. PE
Students' epistemologies about experimental physics: Validating the Colorado Learning Attitudes about Science Survey for Experimental Physics
Student learning in instructional physics labs represents a growing area of
research that includes investigations of students' beliefs and expectations
about the nature of experimental physics. To directly probe students'
epistemologies about experimental physics and support broader lab
transformation efforts at the University of Colorado Boulder (CU) and
elsewhere, we developed the Colorado Learning Attitudes about Science Survey
for Experimental Physics (E-CLASS). Previous work with this assessment has
included establishing the accuracy and clarity of the instrument through
student interviews and preliminary testing. Several years of data collection at
multiple institutions has resulted in a growing national data set of student
responses. Here, we report on results of the analysis of these data to
investigate the statistical validity and reliability of the E-CLASS as a
measure of students' epistemologies for a broad student population. We find
that the E-CLASS demonstrates an acceptable level of both validity and
reliability on measures of, item and test discrimination, test-retest
reliability, partial-sample reliability, internal consistency, concurrent
validity, and convergent validity. We also examine students' responses using
Principal Component Analysis and find that, as expected, the E-CLASS does not
exhibit strong factors.Comment: 10 pages, 4 figures, 7 tables, submitted to Phys. Rev. ST - PE
Properties of air and combustion products of fuels with air
Thermodynamic and transport properties include ratio of specific heats, molecular weight, viscosity, heat capacity, thermal conductivity, and Prandtl number. Properties are calculated from 300 to 2500 degrees K and for pressures of three and ten atmospheres
CR Structures and Asymptotically Flat Space-Times
We discuss the unique existence, arising by analogy to that in algebraically
special space-times, of a CR structure realized on null infinity for any
asymptotically flat Einstein or Einstein-Maxwell space-time.Comment: 6 page
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