Introduction This study involved a systematic literature review to document the sources behind publications and citations that comprise knowledge about rates of braille usage/literacy among people with visual impairments in the United States. Methods Predefined search criteria were used to extract publications that potentially mentioned claims about braille literacy and usage rates, dating back as far as the early 20th century. Systematic analyses narrowed the set of publications to a collection of 95 articles and manuscripts that made specific statements about the prevalence of braille readership. Results The analysis revealed that even in peer-reviewed publications, many claims about braille literacy are made without citations to dependable sources. All identified citations used as the basis for braille literacy rates since the 1970s can be traced back to two primary sources: a National Library Service report from 1979 and the American Printing House for the Blind (APH) Federal Quota data (which should not be used as a source for braille literacy rates). Discussion This research explains the source of the often-cited “10%” statistic. The findings also challenge the field to question the bases for statements about braille literacy rates, including asking, “What do we mean by braille literacy?” Implications for Practitioners There is no current source of data that succinctly measures braille literacy rates in the United States, and there are no data that explain whether braille literacy rates are rising or declining. Making effective, data-based decisions requires asking the right questions and being informed readers of research in the field of visual impairment.

It is well known that people who read print or braille sometimes make eye or finger movements against the reading direction. The way these regressions are elicited has been studied in detail by manipulating linguistic aspects of the reading material. Actually, it has been shown that reducing the physical intensity or clarity of the visual input signal can also lead to increased regressions during reading. We asked whether the same might be true in the haptic realm while reading braille. We set the height of braille dots at three different levels (high, medium, and low) and asked adult blind, practiced braille readers to read standardized texts without any repetition of content. The results show that setting the braille dot height near the tactile threshold significantly increased the frequency of regressive finger movements. Additionally, at the lowest braille dot height, braille reading speed significantly diminished. These effects did not occur at braille dot heights that were closer to the height of standard braille (medium and high). We tentatively conclude that this effect may be due to a heightened sense of uncertainty elicited by perception near the threshold that seems to be common to the reading process, independent of the sensory input modality. Furthermore, the described effect may be a feature of a brain area that contributes to the reading process mediated by vision as well as touch.

Attachment studies with diverse populations enrich the understanding of infants' socioemotional development by documenting both universal and idiosyncratic aspects of attachment. Given the effects of attachment in children's socioemotional outcomes, such studies are necessary to investigate the impact of children's sensory impairments on attachment development. Yet, very little attachment research has focused on infants with visual impairment (VI infants), a population in which infant-caregiver emotional exchanges through visual means are reduced/absent. We investigated the applicability of the Strange Situation Paradigm (SSP), with added instructions to compensate for degraded visual input, in 20 VI infants (with no additional disabilities and who were receiving developmental counseling). In all but 1 of the SSPs coded, VI infants displayed observable attachment behavior that was classifiable. Nineteen VI infants showed attachment by 12 months of age. Across the ages tested (fractional age range = 0.9-2.33 months), most VI infants' attachment patterns were classified as secure and organized.

Fingertip positions can be conceptualized as Brownian particles within a force field. Using stochastic differential equations (SDEs) the force field and its associated potential function can be formally related to observed fingertip positions. Using observed fingertip positions the force field can then be “solved.” This provides a means of describing, comparing, and simulating finger-movement trajectories without formulating the kinematics of the hand. Through discretization of SDEs, the resulting mathematical forms are merely regression equations, which can be solved using familiar mathematical tools such as ordinary least squares and maximum likelihood estimation. Experimental “effects” are specified in the force-field part of the regression, and the Brownian perturbances as the random error of the regression. Using SDEs to specify potential functions can support haptic scientists performing exploratory data analysis, wishing to summarize finger-movement trajectories, compare and test differences in finger-movement trajectories between participants, groups of participants, or experimental conditions, and simulate/predict finger-movement trajectories.

Fingertip positions can be tracked using a variety of motion capture methods, raising the question of how to describe, compare, measure effects on, and simulate finger-movement trajectories. This paper provides a solution using stochastic differential equations (SDEs). In this approach, finger positions are conceptualized as Brownian particles. Effects on finger positions, from the stimulus and experimental manipulations, are formalized using a potential function and associated force field. Unlike previous SDE approaches to model animal movements, the current treatment relates fingertip positions and potential functions using SDEs that account for movement persistence. Using the SDE approach, observed fingertip positions can be used to “solve” the potential function through conventional regression methods. The resulting potential functions can be used to summarize finger-movement trajectories, and to compare and simulate trajectories.

Intelligence (IQ) tests are used to determine a child's intellectual abilities relative to his or her age group. Results are used to diagnose learning disabilities, intellectual disabilities, and giftedness; and to inform psychoeducational interventions and student education plans. The majority of tasks on intelligence tests require vision, such as visual pattern recognition. Therefore, psychologists typically use verbal sections, especially vocabulary tests, to assess students who have visual impairments. In a recent study (Morash & McKerracher, 2016), we investigated whether a common vocabulary test produced scores from children with visual impairments that were reliable. We found that reliability was not high enough to be used for high-stakes decisions, such as determining diagnoses or educational programming. Therefore, we do not recommend common verbal tests developed for sighted children be used with children who have visual impairments. Practitioners need to be wary and watchful of any diagnoses based on inappropriate intelligence measures. Previously noted issues with sighted-normed verbal tests Prior to our study, other researchers had not considered whether administering common verbal tests to children with visual impairments may produce scores with low reliability (see, for example, Crepeau-Hobson & Vujeva, 2012; Nelson, Dial, & Joyce, 2002). Instead the literature noted that using only verbal tests neglects important nonverbal abilities, such as spatial reasoning, which results in an incomplete assessment of intellectual functioning (Bauman & Kropf, 1979; Dekker, 1993; Gutterman, Ward, & Genshaft, 1985; Lund, Miller, & Ganz, 2014; Miller & Skillman, 2003). In addition, scores on common verbal tests are compared to normative data (norms) from sighted children, which may not be appropriate (see, for example, Dekker, 1993; Hull & Mason, 1995; Tillman & Bashaw, 1968; Vander Kolk, 1977). Comparison to norms reveals whether the child scored below or above average for his age group, and by how much; resulting in an IQ score and possible diagnosis of learning disability, intellectual disability, or giftedness. However, children with visual impairments tend to score higher or lower than their sighted peers on many tasks, for reasons other than their intelligence. For example, they tend to score higher on tests of verbal working memory (see, for example, Hull & Mason, 1995), presumably due to daily practice using verbal working memory strategies, such as counting steps, to complete tasks without vision. Although scores may be inflated or deflated due to using sighted norms, it has been suggested that sighted-normed verbal tests can be useful in providing insight into the child's functioning relative to sighted peers (Dial & Dial, 2010), to track a child's performance over time, and to compare children with visual impairments to one another. Unfortunately, these uses are invalidated by low reliability. Low reliability of sighted-normed verbal tests Reliability refers to the consistency of test scores. Low reliability is a separate, and possibly more severe, problem than inflated or deflated scores. If test scores have low reliability, an unacceptably large part of the score is due to random error--as if a coin flip determines a large part of a child's score and diagnosis. Scores with low reliability have limited value for comparing performance over time and across children, since psychologists cannot trust that scores reflect meaningful variations instead of random errors. Although common verbal tests produce scores with good reliability for sighted children, they are not guaranteed to do so with children who have visual impairments (Loevinger, 1957). It is not unreasonable to expect differential functioning, because children who have visual impairments can experience atypical conceptual and semantic development (see, for example, Pring, Freestone, & Katan, 1988). …

The most common and advocated assessment approach when a child cannot access visual materials is to use the verbal subscales of a test the psychologist already has and is familiar with. However, previous research indicates that children with visual impairments experience atypical verbal development. This raises the question of whether verbal subscale scores retain their reliability and interpretation validity when given to children with visual impairments. To answer this question, we administered a vocabulary subscale from a common intelligence test along with several nonverbal subscales to 15 early-blind adolescents (onset of ≤2 years). Reliability of only the vocabulary test scores was insufficient for high-stakes testing. This finding points to the broader issue of difficulties in assessing populations of exceptional children who experience atypical development trajectories, possibly making their assessment with common tests inappropriate. (PsycINFO Database Record

Coordination of attention between a social partner and an external focus of shared interest, called joint engagement, is associated with positive developmental outcomes such as better language, socio-emotional, and theory of mind skills in sighted infants. Current measures of joint engagement rely on an infant's visual behaviors, making it difficult to study joint engagement in infants with low or no vision. In a naturalistic observational study, 20 infants with various levels of visual impairments - mean ages: 1.08 years (N=9) and 1.62 years (N=18), were videotaped during 30-min free play sessions with their caregivers. Seven infants were tested at both ages. Videos were coded to determine the percentage of time the dyads participated in joint engagement. Results showed that all visually impaired infants participated in joint engagement, with a significant increase between earlier and later ages. Infants' visual impairment levels were described in terms of visual acuity and contrast sensitivity as measured using both visual evoked potential and preferential looking techniques. Of the visual measurements, infants' reduction in contrast sensitivity measured with preferential looking, alone, predicted the infants' percentage of time in joint engagement across ages. Contrary to prior research that exclusively focused on visual acuity, this finding supports the need to include contrast sensitivity measurements in studies with visually impaired infants.

Refreshable displays for tactile graphics are typically composed of pins that have smaller diameters and spacing than standard braille dots. We investigated configurations of high-density pins to form braille text on such displays using non-refreshable stimuli produced with a 3D printer. Normal dot braille (diameter 1.5 mm) was compared to high-density dot braille (diameter 0.75 mm) wherein each normal dot was rendered by high-density simulated pins alone or in a cluster of pins configured in a diamond, X, or square; and to “blobs” that could result from covering normal braille and high-density multi-pin configurations with a thin membrane. Twelve blind participants read MNREAD sentences displayed in these conditions. For high-density simulated pins, single pins were as quickly and easily read as normal braille, but diamond, X, and square multi-pin configurations were slower and/or harder to read than normal braille. We therefore conclude that as long as center-to-center dot spacing and dot placement is maintained, the dot diameter may be open to variability for rendering braille on a high density tactile display.

Assistive technology (AT) is critical for K-12 students who have visual impairments to engage with their education and is predictive of positive postsecondary outcomes and future employment. Teachers of students with visual impairments (TVIs) act as the primary gatekeepers of AT for these students. Unfortunately, only about 40% of TVIs integrate AT into their practice. Efforts to predict TVIs’ AT proficiency based on their preservice training have been unsuccessful. The current study proposes and confirms that TVIs’ AT proficiency is related to their identification with a social community of practice (CoP) that values AT. Results from n = 505 North American TVIs produced a Spearman’s correlation of ρ = 0.49 between estimated AT proficiency and CoP identification. The relationship was strongest among TVIs with lower AT proficiency and CoP identification. Results have implications for industry, researchers, teacher preparation programs, personnel who administer and train assistive technologies, and policymakers concerned with ensuring that AT is available to students who have visual impairments. Mere availability of AT is insufficient to ensure its successful introduction to K-12 students with visual impairments, which relies on TVIs’ AT proficiency for meaningful implementation. Developers and advocates of AT for K-12 students with visual impairments must consider the social context in which AT proficiency develops and provide appropriate social supports.

Finger tracking has the potential to expand haptic research and applications, as eye tracking has done in vision research. In research applications, it is desirable to know the bias and variance associated with a finger-tracking method. However, assessing the bias and variance of a deterministic method is not straightforward. Multiple measurements of the same finger position data will not produce different results, implying zero variance. Here, we present a method of assessing deterministic finger-tracking variance and bias through comparison to a non-deterministic measure. A proof-of-concept is presented using a video-based finger-tracking algorithm developed for the specific purpose of tracking participant fingers during a psychological research study. The algorithm uses ridge detection on videos of the participant’s hand, and estimates the location of the right index fingertip. The algorithm was evaluated using data from four participants, who explored tactile maps using only their right index finger and all right-hand fingers. The algorithm identified the index fingertip in 99.78 % of one-finger video frames and 97.55 % of five-finger video frames. Although the algorithm produced slightly biased and more dispersed estimates relative to a human coder, these differences (x=0.08 cm, y=0.04 cm) and standard deviations (σ x =0.16 cm, σ y =0.21 cm) were small compared to the size of a fingertip (1.5–2.0 cm). Some example finger-tracking results are provided where corrections are made using the bias and variance estimates.

Movement strategies were investigated in a one-handed haptic search task in which blindfolded-sighted participants used either one or five fingers to find a landmark on an unstructured tactile map. Search theory predicts that systematic strategies, such as spirals, zigzags, and parallel sweeps, should be more prevalent when the searcher's detection radius is small (one finger) and less common when the detection radius is large (five fingers). As predicted, systematic strategies were more common in one-finger than five-finger search. Participants were able to exploit the larger detection radius during five-finger searches to detect targets with any of their fingers, and in one-finger search used more systematic strategies. For the most part, participants' fingers moved together during five-finger search, expanding and moving quickly when looking for search targets/distractors, and contracting and moving slowly when examining search targets/distractors. There was no evidence of fingers being used as spatial anchors or other independent finger movements in five-finger search. While targets could be found with any fingers, examination was primarily accomplished using the index and middle fingers. Overall, these results indicate that untrained sighted participants will use optimal systematic strategies during haptic search, and this behavior is appropriately modulated by detection radius.

Movement strategies were investigated in a one-handed haptic search task where blindfolded sighted participants used either one or five fingers to find a landmark on an unstructured tactile map. Search theory predicts that systematic strategies, such as parallel sweeps and spirals, should be more prevalent when the searcher's detection radius is small (one finger) than when the detection radius is large (five fingers). Movement patterns were classified as either non-systematic or systematic. As predicted by search theory, systematic strategies were more common in one-finger than five-finger searches. Overall, these results indicate that systematic haptic search strategies are used and modulated by detection radius for untrained sighted participants.

This article compares two methods of employing novice Web workers to author descriptions of science, technology, engineering, and mathematics images to make them accessible to individuals with visual and print-reading disabilities. The goal is to identify methods of creating image descriptions that are inexpensive, effective, and follow established accessibility guidelines. The first method explicitly presented the guidelines to the worker, then the worker constructed the image description in an empty text box and table. The second method queried the worker for image information and then used responses to construct a template-based description according to established guidelines. The descriptions generated through queried image description (QID) were more likely to include information on the image category, title, caption, and units. They were also more similar to one another, based on Jaccard distances of q-grams, indicating that their word usage and structure were more standardized. Last, the workers preferred describing images using QID and found the task easier. Therefore, explicit instruction on image-description guidelines is not sufficient to produce quality image descriptions when using novice Web workers. Instead, it is better to provide information about images, then generate descriptions from responses using templates.

Tactile graphics use raised lines, textures, and elevations to provide individuals with visual impairments access to graphical materials through touch. Tactile graphics are particularly important for students in science, technology, engineering, and mathematics (STEM) fields, where educational content is often conveyed using diagrams and charts. However, providing a student who has a visual impairment with a tactile graphic does not automatically provide the student access to the graphic's educational content. Instead, the student may struggle to decipher subtle differences between textures or line styles, and must deal with cramped and confusing placement of lines and braille. These format-related issues prevent students with visual impairments from accessing educational content in graphics independently, because they necessitate the students ask for sighted clarification. We propose a machine-vision based "tactile graphics helper" (TGH), which tracks a student's fingers as he/she explores a tactile graphic, and allows the student to gain clarifying audio information about the tactile graphic without sighted assistance. Using an embedded mixed-methods case study with three STEM university students with visual impairments, we confirmed that format-related issues prevent these students from accessing some graphical content independently, and established that TGH provides a promising approach for overcoming tactile-graphic format issues.

Introduction: This article presents an instrument that measures the assistive technology proficiency of teachers of students with visual impairments and their identification with a community of practice that values assistive technology. Teachers' deficits in assistive technology proficiency negatively impact students who are visually impaired by stunting the development of assistive technology skills, ultimately resulting in poorer postsecondary education and employment outcomes. Identification with a community of practice that values assistive technology may be supportive of the technological proficiency of teachers of students with visual impairments. Method: Assistive technology proficiency and community of practice identification dimensions were defined and outlined in rubric-like "construct maps." A survey that was created to place teachers of students with visual impairments within each construct map was completed by 33 Californian teachers. Survey performance was evaluated by estimating Rasch models, which provided information on relative question difficulty and question performance. Results: Estimated question difficulties revealed expected patterns. Only two survey questions performed irregularly (infit > 1.33). Internal reliability was good (Cronbach's Alpha = 0.80) for assistive technology proficiency, and acceptable (Cronbach's Alpha = 0.70) for community of practice identification. Discussion: The findings suggest the survey reliably measured the assistive technology proficiency and identification with a community of practice that values technology in this sample of teachers. Utilization of this tool may enable the objective evaluation of assistive technology proficiency of teachers pre-and post-training. Implications for practitioners: Creation of a reliable instrument that measures these constructs will support investigations in how one relates to the other, and will consider how professional development may be designed to better support the use of assistive technology by teachers.

It remains controversial whether using two hands and multiple fingers provides any perceptual advantage over a single index finger. The present study examines this long-running question in the haptic-exploration literature by applying rigorous, psychophysical, and mathematical modeling techniques. We compared the performance of fourteen blindfolded sighted participants on seven tactile-map tasks using seven finger conditions. All tasks were benefited by multiple fingers, but it varied whether multiple fingers were beneficial on one hand, two hands, or both. Line-tracing tasks were performed faster when two hands were used, but not more than one finger per hand. Local and global search tasks were faster with multiple fingers, but not two hands. Distance comparison tasks were also performed faster with multiple fingers, and sometimes with two hands. Lastly, moving in a straight line was faster with multiple fingers, but was especially difficult with just two index fingers. These results provide empirical evidence that multiple hands and fingers benefit haptic perception, but the benefits are more complex than simply extending the tactile field of 'view'. This analogy between touch and vision fails to account for the autonomous movements and sensations of the fingers, which we show benefit the haptic perceptual system.