Breaking the Language Barrier: Equitable Assessment in General Chemistry

Because language provides the framework through which knowledge is constructed, it is crucial to consider the ways in which students with limited English proficiencies are able to express their understanding. English language learners (ELLs) make up a significant portion of the student body in the education system and represent many ethnic and racial minorities in STEM (Science, Technology, Engineering & Mathematics) fields (Burke & Mattis, 2007). Despite the national push to build a more diversified, STEM-ready workforce, there is little research that considers the way ELLs are assessed in STEM courses at the postsecondary level. Literature reports that science tests that assess the knowledge of students who are still in the process of learning language skills are inadequate and threaten the validity of assessments. The way students interpret and respond to test items are mediated by linguistic and cultural factors, such as home language and prior educational experiences in the country of origin. Therefore, language and cultural factors must be taken into consideration in order to improve the validity of classroom assessments in science courses. Students’ experiences in introductory science courses, such as biology and general chemistry, are critical in their choice of staying in or switching out of STEM majors (Astin & Astin, 1992). Of these, general chemistry is one of the most feared science courses for undergraduate students (Carter & Brickhouse, 1989), and it is a required course for many STEM-bound career paths. Most students struggle with understanding chemistry and many do not succeed on chemistry assessments (Woldeamanuel et al., 2014). Research suggests that scientific language literacy has a significant influence on all students’ success in chemistry assessments, including that of both ELLs and Native English Speakers (NES) (Woldeamanuel et al., 2014). Therefore, one way to support the success of all students—and particularly of ELLs—on chemistry assessments is to address the linguistic complexity inherent in chemistry assessment questions. One way to ease the burden of linguistic complexity during testing is to apply the Equity Framework of Classroom Assessments (EFCA) (Siegel, 2008) to written test items. This framework aims to make test items more accessible without simplifying the content. In general chemistry, the EFCA can be implemented to make commonly-used items more accessible to all students using modifications such as division of prompt into smaller parts, reduction of non-essential information, adding representation, and simplifying sentence structure. This study investigated the perceptions of ELL and NES students about general chemistry assessment items that were modified according to the EFCA. ELL students reported to experience difficulties understanding items that included complex linguistic features such as complex sentence structures and vocabulary. The results show that ELLs perceived language-independent features of items to be the most helpful on assessment items. These features included the formatting of items and the visual representations embedded in items. Although NES students also found the visual features of items to be helpful, they used language-dependent features to understand and set up the problems. The results suggest that ELL students particularly benefited from scaffolding-related features in assessment items. Features that provided content support and guidance for identifying key information and setting up the problems were more helpful for ELL than NES students. Both groups of students found features that provided contextualization in the form of storylines and/or background information which were not directly related to solving the assessment items to be irrelevant, challenging, and/or confusing. Both groups of students reported that they preferred the revised versions—which included the modifications recommended by the EFCA—over the original versions of the assessment items presented to them. The findings suggest that most of the modifications employed in the EFCA are effective in mitigating linguistically complex elements of written assessments items about limiting reactant and percent yield in general chemistry and support the assessment of both ELL and NES students

Faculty Perceptions of the Factors Influencing Success in STEM fields

The recent decline in the number of graduates in the fields of Science, Technology, Engineering and Mathematics (STEM) has significant implications for the nation’s economic and societal well-being (PCAST, 2012). Because university faculty members’ interactions with students—both in and out of the classroom—have a significant impact on student recruitment and retention and because faculty beliefs have a significant impact on faculty practices (Astin & Astin, 1992), we have interviewed university faculty members in order to examine their perceptions of successful STEM students. Here, we report faculty members’ perceptions of the characteristics of successful tertiary STEM students, as well as their perceptions of the major obstacle to student success in STEM courses and programs of study. While faculty perceptions of the characteristics of successful STEM students generally align with the research literature, faculty did not mention experiences or instructional strategies they could implement in their classrooms to help students develop these characteristics. The results of the current study could inform the design of faculty professional development to ensure that faculty are aware of the various ways they can support student success in STEM fields

Faculty Perceptions of Student Recruitment and Retention in STEM Fields

According to the President's Council of Advisors on Science and Technology (PCAST, 2012), there is a need to produce one million more STEM (Science, Technology, Engineering, and Mathematics) graduates in the U.S. over the next decade. Thus, more students must be recruited into and retained in STEM degrees of study. Because faculty are considered influential in students' choices to pursue and remain in STEM disciplines, we interviewed university STEM faculty in order to identify their perceptions of student recruitment and retention in STEM fields. Our data indicate that faculty are generally unaware of or not worried about the need to produce additional STEM graduates. Additionally, faculty seem to be unaware of the actions they might take to positively influence STEM recruitment and retention at the post-secondary level. Here, we specifically discuss faculty perceptions of (1) the gap between the number of STEM graduates and the number of STEM workers available for STEM-related jobs, (2) why students may not be going into or remaining in STEM fields, and (3) their own roles in recruiting and retaining students in STEM fields

High-resolution topography and anthropogenic feature extraction: testing geomorphometric parameters in floodplains

In floodplains, anthropogenic features such as levees or road scarps, control and influence flows. An up-to-date and accurate digital data about these features are deeply needed for irrigation and flood mitigation purposes. Nowadays, LiDAR Digital Terrain Models (DTMs) covering large areas are available for public authorities, and there is a widespread interest in the application of such models for the automatic or semiautomatic recognition of features. The automatic recognition of levees and road scarps from these models can offer a quick and accurate method to improve topographic databases for large-scale applications. In mountainous contexts, geomorphometric indicators derived from DTMs have been proven to be reliable for feasible applications, and the use of statistical operators as thresholds showed a high reliability to identify features. The goal of this research is to test if similar approaches can be feasible also in floodplains. Three different parameters are tested at different scales on LiDAR DTM. The boxplot is applied to identify an objective threshold for feature extraction, and a filtering procedure is proposed to improve the quality of the extractions. This analysis, in line with other works for different environments, underlined (1) how statistical parameters can offer an objective threshold to identify features with varying shapes, size and height; (2) that the effectiveness of topographic parameters to identify anthropogenic features is related to the dimension of the investigated areas. The analysis also showed that the shape of the investigated area has not much influence on the quality of the results. While the effectiveness of residual topography had already been proven, the proposed study underlined how the use of entropy can anyway provide good extractions, with an overall quality comparable to the one offered by residual topography, and with the only limitation that the extracted features are slightly wider than the investigated one