A simple proof of the spearman-brown formula for continuous test lengths

A direct proof is given for the generalized Spearman-Brown formula for any real multiple of test length.     

Perceptions of Forgetfulness in Adulthood

Abstract

In two experiments, we examined younger and older participants’ appraisals of memory failures in fictitious characters portrayed as younger (in their 20’s to 30’s) or older (in their 60’s to 70’s) adults. Participants read vignettes where forgetful behavior had minor or more severe consequences for the target character (Experiment 1) or for the character and others in the social environment (Experiment 2). Participants rated potential causes of the forgetfulness and opinions concerning the target character’s cognitive health. In Experiment 1, an age-based double standard was observed, where both age groups rated ability as a cause of forgetting more often for older than younger characters. Ratings of forgetfulness as a sign of mental difficulty, need for memory training, and professional evaluation were also higher for older compared to younger characters. In Experiment 2, the Attribution Type by Target Age interaction effect was replicated. Ability and effort contributed to the significance of the interaction, confirming the reliability and generalizability of the age-based double standard. Forgetfulness was rated as a sign of mental difficulty more often for the older than younger characters, replicating Experiment 1. In both experiments, the consequences of the forgetting had a large impact on the attribution and opinion ratings for younger and older forgetful characters. These data suggest that people of all ages evaluate forgetful characters in light of situational outcomes as well as ageist presumptions of cognitive frailty in later life.     

Exploring tensions of using interpretative phenomenological analysis in a domain with conflicting cultural practices

ABSTRACT

The philosophical foundations of interpretative phenomenological analysis (IPA)—phenomenology, hermeneutics, and idiography—guide its practice and use. However, this foundation is often at odds with cultural practices of disciplines that value post-positivist perspectives emphasizing that reality can be objectively known. The conflict between the philosophical underpinnings of the methodology and the cultural practices of particular disciplines can serve to limit the use and acceptance of IPA. This article highlights ways researchers can use IPA even when the underlying tenets of that methodological approach may be in conflict with disciplinary norms. As such, we have set out to explore the tensions that accompany the choice to use IPA in the context of engineering education research within the United States. As a group of engineering education researchers, we drew upon collaborative inquiry to systematically examine our use of IPA. Our exploration of using IPA, as connected to everyday practice in a discipline that takes a postpositivist stance toward knowledge generation, provides examples for the use of IPA in tension with these disciplinary norms.     

An Examination of the Connections Between Eating Disorder Symptoms,Perceived Burdensomeness,Thwarted Belongingness,and Suicide Risk Among Undergraduate Students

Suicide attempts and premature mortality due to suicide are elevated in people with eating disorders. Informed by the interpersonal theory of suicide, two studies examined the role of perceived burdensomeness and thwarted belongingness in explaining the association between eating disorder symptoms and suicide risk. Results indicated that various eating disorder symptoms had an indirect effect on suicide risk through perceived burdensomeness and thwarted belongingness. Targeting perceived burdensomeness and thwarted belongingness may be useful for decreasing suicide risk among undergraduates with eating disorder symptoms.     

Characterizing perceptual learning with external noise

Performance in perceptual tasks often improves with practice. This effect is known as ‘perceptual learning,’ and it has been the source of a great deal of interest and debate over the course of the last century. Here, we consider the effects of perceptual learning within the context of signal detection theory. According to signal detection theory, the improvements that take place with perceptual learning can be due to increases in internal signal strength or decreases in internal noise. We used a combination of psychophysical techniques (external noise masking and double-pass response consistency) that involve corrupting stimuli with externally added noise to discriminate between the effects of changes in signal and noise as observers learned to identify sets of unfamiliar visual patterns. Although practice reduced thresholds by as much as a factor of 14, internal noise remained virtually fixed throughout training, indicating learning served to predominantly increase the strength of the internal signal. We further examined the specific nature of the changes that took place in signal strength by correlating the externally added noise with observer’s decisions across trials (response classification). This technique allowed us to visualize some of the changes that took place in the linear templates used by the observers as learning occurred, as well as test the predictions of a linear template-matching model. Taken together, the results of our experiments offer important new theoretical constraints on models of perceptual learning.     

Mapping Word to World in ASL: Evidence from a Human Simulation Paradigm

Across languages, children map words to meaning with great efficiency, despite a seemingly unconstrained space of potential mappings. The literature on how children do this is primarily limited to spoken language. This leaves a gap in our understanding of sign language acquisition, because several of the hypothesized mechanisms that children use are visual (e.g., visual attention to the referent), and sign languages are perceived in the visual modality. Here, we used the Human Simulation Paradigm in American Sign Language (ASL) to determine potential cues to word learning. Sign-naïve adult participants viewed video clips of parent–child interactions in ASL, and at a designated point, had to guess what ASL sign the parent produced. Across two studies, we demonstrate that referential clarity in ASL interactions is characterized by access to information about word class and referent presence (for verbs), similarly to spoken language. Unlike spoken language, iconicity is a cue to word meaning in ASL, although this is not always a fruitful cue. We also present evidence that verbs are highlighted well in the input, relative to spoken English. The results shed light on both similarities and differences in the information that learners may have access to in acquiring signed versus spoken languages.