A Didactic Sequence of Elementary Geometric Optics Informed by History and Philosophy of Science

The concepts and instruments required for the teaching and learning of geometric optics are introduced in the didactic process without a proper didactic transposition. This claim is secured by the ample evidence of both wide- and deep-rooted alternative concepts on the topic. Didactic transposition is a theory that comes from a reflection on the teaching and learning process in mathematics but has been used in other disciplinary fields. It will be used in this work in order to clear up the main obstacles in the teaching-learning process of geometric optics. We proceed to argue that since Newton’s approach to optics, in his Book I of Opticks, is independent of the corpuscular or undulatory nature of light, it is the most suitable for a constructivist learning environment. However, Newton’s theory must be subject to a proper didactic transposition to help overcome the referred alternative concepts. Then is described our didactic transposition in order to create knowledge to be taught using a dialogical process between students’ previous knowledge, history of optics and the desired outcomes on geometrical optics in an elementary pre-service teacher training course. Finally, we use the scheme-facet structure of knowledge both to analyse and discuss our results as well as to illuminate shortcomings that must be addressed in our next stage of the inquiry.     

How fast can we read in the mind? Developmental trajectories of silent reading fluency

The silent reading fluency is not an observable behaviour and, therefore, its evaluation is perceived as more challenging and less reliable than oral reading fluency. The present research is aimed to measure the silent reading speed in a sample of proficient students, assessed by an original silent reading fluency task, based on behavioural indicators of the silent reading speed. A total of 325 high school and university skilled students (age range 14–23 years) have been assessed using 3 tasks aimed to evaluate the oral reading speed (lists of words, lists of pseudowords and narrative text) and one task aimed to measure the silent reading speed. The average silent reading speed in our sample was around 12.5 syll/sec, almost double than the oral reading speed rate. The silent reading speed had an increase from 9.13 to 12.38 syll/sec from the first year of high school (ninth grade) to the fifth year of University. Conversely, the oral reading speed remained substantially unchanged for the entire academic course. Our results showed that the reading fluency in silent mode tends to increase up to the last years of University and it may be considered the most rapid and efficient reading mode. This study highlights the importance of including both silent and oral reading modes in the assessment of the older students and young adults, since silent reading is the main reading mode for proficient readers.     

Indexed Captioned Searchable Videos: A Learning Companion for STEM Coursework

Videos of classroom lectures have proven to be a popular and versatile learning resource. A key shortcoming of the lecture video format is accessing the content of interest hidden in a video. This work meets this challenge with an advanced video framework featuring topical indexing, search, and captioning (ICS videos). Standard optical character recognition (OCR) technology was enhanced with image transformations for extraction of text from video frames to support indexing and search. The images and text on video frames is analyzed to divide lecture videos into topical segments. The ICS video player integrates indexing, search, and captioning in video playback providing instant access to the content of interest. This video framework has been used by more than 70 courses in a variety of STEM disciplines and assessed by more than 4000 students. Results presented from the surveys demonstrate the value of the videos as a learning resource and the role played by videos in a students learning process. Survey results also establish the value of indexing and search features in a video platform for education. This paper reports on the development and evaluation of ICS videos framework and over 5 years of usage experience in several STEM courses.     

Students’ Development of Representational Competence Through the Sense of Touch

Electromagnetism is an umbrella encapsulating several different concepts like electric current, electric fields and forces, and magnetic fields and forces, among other topics. However, a number of studies in the past have highlighted the poor conceptual understanding of electromagnetism concepts by students even after instruction. This study aims to identify novel forms of “hands-on” instruction that can result in representational competence and conceptual gain. Specifically, this study aimed to identify if the use of visuohaptic simulations can have an effect on student representations of electromagnetic-related concepts. The guiding questions is How do visuohaptic simulations influence undergraduate students’ representations of electric forces? Participants included nine undergraduate students from science, technology, or engineering backgrounds who participated in a think-aloud procedure while interacting with a visuohaptic simulation. The think-aloud procedure was divided in three stages, a prediction stage, a minimally visual haptic stage, and a visually enhanced haptic stage. The results of this study suggest that students’ accurately characterized and represented the forces felt around a particle, line, and ring charges either in the prediction stage, a minimally visual haptic stage or the visually enhanced haptic stage. Also, some students accurately depicted the three-dimensional nature of the field for each configuration in the two stages that included a tactile mode, where the point charge was the most challenging one.     

To Apply or Not to Apply: FAFSA Completion and Financial Aid Gaps

In the United States, college students must complete the Free Application for Student Federal Aid (FAFSA) to access federal aid. However, many eligible students do not apply and consequently forgo significant amounts of financial aid. If students have perfect information about aid eligibility, we would expect that all eligible students complete FAFSA and no aid would go unclaimed. Using data from the National Postsecondary Student Aid Survey, I estimate a multinomial logit model which controls for all variables that contribute to aid eligibility and other student characteristics that may deter FAFSA completion. I find that students who are lower middle income, white, male and independent from parents are less likely to complete FAFSA even when they are eligible for aid. Using propensity score matching, I find that each year applicants forgo $9,741.05 in total aid (including grant and loan aid) which includes $1,281.00 of Pell Grants, $2,439.50 of the balance subsidized student loans, $1,986.65 of the balance of unsubsidized student loans, and $1,016.04 of institutional grants. These aid totals aggregate to $24 billion annually.     

Strategic Use of FAFSA List Information by Colleges

Students filling out the FAFSA list colleges and universities where they wish their data, sent. Until recently, colleges were provided this list, and the practice was suspended, given concerns that colleges were using the list to strategically allocate aid. Using the, 2011–2012 NPSAS, we analyze student financial aid packages to determine if list position, affects aid. We find little evidence that it does.     

Two teacher quality measures and the role of context: evidence from Chile

This research examines empirically the relationship between two measures of teacher quality: one based on professional standards and a second one using teacher value-added estimates. It also studies the extent to which teacher observable characteristics, such as teacher training variables, are associated to better performance on either of these measures and whether any of these two assessments is able to effectively measure teacher quality isolated from the effect of the context where teachers work. Context in this article is defined as any variable that is not under the direct control of the teacher but plays an important role on student learning and we believe is captured by school and municipal variables. The study uses hierarchical linear models and information from national and standardized assessments from Chile, specifically from the municipal education sector. Results show a small correlation between the two measures of teacher quality, in the lower end of results from previous studies conducted in the USA, and suggest that there is only a limited relationship between both measures of teacher quality. Teacher initial education type and professional development were statistically associated only to the standard-based measure of teacher quality. Context (both the school and municipal levels) plays an important role in the teacher effect measure, and in the standard-based measures, therefore, we conclude that neither of these measures are context-free. We expect that these results will contribute to the discussion about how to best measure teacher quality and how to evaluate teacher performance both in Chile and other parts of the world.