The psychometric characteristics of a phonological processing battery were examined using kindergarten (n = 95), first grade (n = 49), and second grade (n = 89) subjects enrolled in public schools. The phonological battery consisted of subtests measuring phonological awareness, phonological access, and phonological coding. The battery also included reading achievement, general intellectual ability, and letter naming/sound knowledge subtests as criterion measures. / The reliability of the battery was assessed by examining both internal consistency estimates and test-retest reliability across all three grades. The internal consistency coefficients for the battery across all ages were satisfactory, with coefficients in the general range of.72 to.95. Test-retest reliabilities over an average interval of 12 weeks were considerably lower (range of.59 to.79 across subtests and grades). / Evidence for the construct validity of the battery included significant correlations among measures of phonological awareness, phonological coding, and phonological access across all three grade levels. For the kindergarten and second grade samples, phonological awareness subtests were significantly correlated, even when the effects of IQ were removed from the matrices. Although the correlations between subtests measuring the three types of phonological processing abilities were minimally significant, factor analytic data supported the existence of separate factors, each of which included subtests representing the three types of phonological processing abilities. / Finally, concurrent validity evidence supported a moderate relationship between the phonological processing measures and reading achievement. Multiple regression analyses identified several subtests which accounted for significant proportions of the variance in reading achievement. Based on the reliability and validity data obtained using this data, a condensed battery was recommended for future research on phonological processing and reading. / Source: Dissertation Abstracts International, Volume: 51-02, Section: B, page: 1015. / Major Professor: Joseph K. Torgesen. / Thesis (Ph.D.)--The Florida State University, 1989.

Children who have been sexually victimized are disadvantaged individuals and members of an oppressed segment of society who clearly merit the assistance of social workers. Responsible practice entails the evaluation of social work practice. The goals of this project were the construction and initial validation of a rapid assessment self-report measurement tool to be used with child and adolescent sexual abuse victims to ascertain the effectiveness of psychotherapeutic intervention. One hundred and three 10 to 17 year old girls who had been the targets of intrafamilial child sexual abuse (incest) participated in the research. Child and adolescent participants completed the draft instrument, the Child Report of Treatment Issue Resolution, as well as the Trauma Symptom Checklist for Children and the Children's Social Desirability Questionnaire. The research participants' caretakers completed the Achenbach Child Behavior Checklist and a background questionnaire. Clinicians provided an opinion as to the progress toward treatment issue resolution for each youngster. Reliability of the study instrument is found to be.94. Content validity was quantified through a process of expert ratings of individual item relevance. Criterion and construct validity are supported by a substantial correlation between the study instrument and the Trauma Symptom Checklist for Children ($-$.74) and a moderate correlation between the study instrument and the Child Behavior Checklist for Children ($-$.40). Evidence for construct validity with regard to the correlations between the CRTIR and Clinicians' Judgement is not provided by the sample data. The correlation between the study instrument and the Children's Social Desirability Questionnaire (.45) does not provide evidence of discriminate validity. Perhaps one of the most intriguing aspects of the results of this study has to do with the issue of social desirability and measurement issues when working with sexually abused youngsters. / Source: Dissertation Abstracts International, Volume: 56-11, Section: A, page: 4556. / Adviser: Dianne Harrison Montgomery. / Thesis (Ph.D.)--The Florida State University, 1995.

Thesis advisor: Pamela J. Grace / Background: As established in professional codes of ethics, critical care nurses must be equipped to provide good (ethical) patient care. This requires ethical awareness, which involves recognizing the ethical implications of all nursing actions (ranging from the mundane to the dilemmatic). Ethical awareness is imperative in successfully addressing patient needs, however, evidence suggests that the ethical import of everyday issues may often go unnoticed by nurses in practice. Assessing nurses’ ethical awareness is a necessary first step in preparing nurses to identify and manage ethical issues in the highly dynamic critical care environment. Purpose: To use Rasch principles to develop a psychometrically sound instrument to assess the nature and extent of critical care nurses’ ethical awareness in the context of everyday nursing practice, and to assess the success of scale development using a Rasch model. Method: An item bank representing nursing actions was developed (33 items). Content validity testing with nursing ethics experts (n = 5) was performed (CVI-I = 1). Eighteen items were selected for face validity testing with graduate nursing students (n = 7). After revisions, two full-scale pilot administrations were performed to run item analyses. Sample: Critical care nurses (n = 116) at a large academic teaching hospital in New England. Results: Pilot test analyses suggest sufficient item invariance across samples and sufficient construct validity. Final analyses demonstrate a progression of items uniformly along a hierarchical continuum; items that match respondent ability levels; response categories that are sufficiently used; a Principle Components Analysis demonstrating randomness of residuals, and adequate internal consistency (Cronbach’s α = 0.83). Mean ethical awareness scores were in the low/moderate range (M = 34.9/54; logit = -0.21). Conclusion: The results of this study suggest the Ethical Awareness Scale (EAS) is a psychometrically sound, reliable, and valid measure of ethical awareness in critical care nurses. / Thesis (PhD) — Boston College, 2017. / Submitted to: Boston College. Connell School of Nursing. / Discipline: Nursing.

A versão infantil do Teste de Ler a Mente nos Olhos (Reading the Mind in Eyes Test - Child Version ) de Simon Baron-Cohen, é composto por 28 fotografias da região dos olhos de indivíduos com diferentes expressões e tem como objetivo uma quantificação da habilidade do indivíduo em inferir estados mentais a partir de expressões faciais, sendo usualmente utilizado como um instrumento para avaliação de Teoria da Mente. Neste trabalho foi feito um estudo de validade de uma versão em português do teste, visando maiores esclarecimentos acerca de suas propriedades psicométricas. O teste foi aplicado em uma amostra controle de 434 crianças de dois estados brasileiros, São Paulo e Santa Catarina, cursando o ensino fundamental e em uma amostra clínica de 20 crianças diagnosticadas com Transtornos do Espectro do Autismo. Foram encontrados um índice de consistência interna (alfa de Cronbach) de 0,718 e variância estatisticamente significativa de acordo com o ano escolar. Não foram encontradas diferenças significativas com relação ao sexo e Estado. Não houve diferença estatisticamente significativa nos escores dos grupos controle e clínico. Os resultados foram, portanto, parcialmente favoráveis para validade de construto, mas não foram encontradas evidências de validade critério / The \"Reading the Mind in Eyes Test - Child Version\" by Simon Baron-Cohen, consists of 28 photographs of the eye region of people with different expressions and aim a quantification of the individual\'s ability to infer mental states from facial expressions, and is usually used as an instrument for assessing Theory of Mind. This paper is a study of validity of a Portuguese version of the test, seeking further clarification about its psychometric properties. The test was applied to a control group of 434 children from two Brazilian states, Sao Paulo and Santa Catarina, in elementary school and a clinical group of 20 children diagnosed with Autism Spectrum Disorders. We found an index of internal consistency (Cronbach\'s alpha) of 0.718 and statistically significant variance in accordance with the school year. There were no significant differences with regard to gender and state. There was no statistically significant difference in the scores of clinical and control groups. The results were therefore partially favorable to construct validity, but there was no evidence of criterion validity

O número de indivíduos obesos quase dobrou desde 1980. Sendo assim, a obesidade torna-se uma ameaça para o equilíbrio físico, mental e social destes indivíduos. Entre os tratamentos psicológicos, destaca-se a Terapia Cognitivo Comportamental, na qual explica que o sistema de crenças de um indivíduo interfere no desenvolvimento de seus sentimentos e comportamentos e, quando distorcido, pode causar tendências disfuncionais de raciocínio. Adaptar instrumentos a fim de aprofundar os estudos em relação ao comportamento alimentar de indivíduos obesos, pode levar a promover ações para promoção de saúde destes. A Dieting Beliefs Scale, composta por 16 afirmações, divididas entre lócus de controle interno (fator 1), lócus que estão além do controle, (fator 2) e lócus externo (fator 3), avalia a relação entre peso e comportamento na dieta. O objetivo deste estudo é adaptar esta escala em adultos para a amostra não clínica (alunos e funcionários da Universidade de Ribeirão Preto - UNAERP) de ambos os sexos e aplicar a versão adaptada para amostra clínica (pacientes da clínica de Nutrição da UNAERP). A análise dos dados da adaptação foi realizada com 197 sujeitos da amostra não clínica e foram realizadas a tradução, análise das evidências de validade (Análise Fatorial Exploratória - AFE - e Análise Fatorial Confirmatória - AFC) e precisão ou fidedignidade (alpha de Cronbach e teste-reteste). A aplicação da escala adaptada foi realizada na amostra clínica (n=114). Em relação aos resultados da tradução, a amostra não clínica não apresentou dúvidas em relação à versão traduzida. Sendo assim, esta foi aplicada em 197 sujeitos desta amostra. Já em relação aos resultados das evidências de validade a AFE constatou que os itens 2, 9, 10, 11 e 15 apresentaram uma carga fatorial alta para o fator 1; os itens 5, 6 e 7 apresentaram alta carga fatorial para o fator 2 e os itens 8, 12 e 13, para o fator 3. Foram excluídos os itens 1, 3, 4 e 16 por terem apresentado carga fatorial abaixo de 0,40. Na AFC, o modelo re-especificado da escala original apresentou ajuste razoável. Os resultados da Precisão ou fidedignidade foi realizada por meio do Alpha de Cronbach (0,404), classificado como moderado e do Teste-reteste (n=96), onde se observou que o fator 1 possui maior índice de correlação (0,620), comparados com os fatores 2 (0,499) e 3 (0,381). Os resultados da aplicação da escala na amostra clínica mostram que há evidências da não relação estatisticamente significativa entre o IMC e os fatores da Escala de Crenças sobre Dieta. Esta amostra pode ter compreensão da importância dos fatores internos em um processo de perda de peso. Assim, as análises estatísticas demonstraram qualidades psicométricas razoáveis. Recomenda-se a utilização deste instrumento para pesquisas a fim de compreender as crenças dos indivíduos em processo de perda de peso e o fator que pode estar interferindo em seu comportamento / The number of obese people has nearly doubled since 1980. Thus, obesity becomes a threat to the physical, mental and social balance of these individuals. Among the psychological treatments, Cognitive Behavioral Therapy stands out, in which it explains that the belief system of an individual interferes in the development of their feelings and behaviors and, when distorted, can cause dysfunctional tendencies of reasoning. Adapting instruments to deepen the studies regarding the eating behavior of obese individuals may lead to actions to promote their health. The Dieting Beliefs Scale, composed of 16 statements, divided between internal control locus (factor 1), locus that are beyond the control (factor 2) and external locus (factor 3), evaluates the relationship between weight and behavior in the diet. The aim of this study is to adapt this scale in adult non-clinical sample (students and staff at the University of Ribeirão Preto - UNAERP) of both genders and apply the version adapted for clinical sample (clinic patients Nutrition UNAERP). The analysis of the adaptation data was performed with 197 subjects from the non-clinical sample and the translation, analysis of the validity evidence (Exploratory Factor Analysis - AFE - and Confirmatory Factor Analysis - AFC) and accuracy or reliability (Cronbach\'s alpha and test -retested). The application of the adapted scale was performed in the clinical sample (n = 114). Regarding the results of the translation, the non-clinical sample showed no doubts about the translated version. Therefore, it was applied in 197 subjects of this sample. Regarding the results of the validity evidence, AFE found that items 2, 9, 10, 11 and 15 presented a high factor load factor 1; Items 5, 6 and 7 presented a high factor load for factor 2 and items 8, 12 and 13 for factor 3. Items 1, 3, 4 and 16 were excluded because they presented a factorial load below 0.40. In the AFC, the re-specified model of the original scale presented a reasonable fit. The results of Accuracy or reliability were performed using Cronbach\'s Alpha (0.404), classified as moderate and Test-retest (n = 96), where it was observed that factor 1 had a higher correlation index (0.620), compared with Factors 2 (0.499) and 3 (0.381). The results of scale application in the clinical sample show that there is evidence of a non-statistically significant relationship between BMI and Dietary Belief Scale factors. This sample may have an understanding of the importance of internal factors in a weight loss process. Thus, the statistical analyzes demonstrated reasonable psychometric qualities. It is recommended to use this tool for research in order to understand the beliefs of individuals in the process of weight loss and the factor that may be interfering in their behavior

Reading comprehension emerges as an important skill set in the early elementary grades. It is supported by component skills including decoding, linguistic knowledge including vocabulary and syntactic knowledge, as well as more complex, higher-level components such as inference making and comprehension monitoring. Theoretical understanding of reading comprehension has historically included reader-focused models, as well as models that include reader-text interaction and text-task interaction. Together, the dimensions of reader, text, and task represent the conceptual space in which comprehension can occur. Using a crossed random-effects model, the probability of a correct item response can be modeled as a function of reader, text, and item characteristics. This approach has been used in several studies of reading comprehension, with informative results. However, to date this work has focused on older readers, or has used relatively small samples of readers. In this study, a crossed random-effects modeling approach was used to analyze a large data set consisting of item response data from a sample of 2,723 Grade 3 students. Student-level predictors of vocabulary knowledge, syntactic knowledge, and word recognition, as well as several categorizations of item type, and passage-level predictors of lexile and several indices of passage complexity were found to be significant predictors of reading comprehension. Cross-level interactions were investigated, and significant interactions were found between student and item predictors, and between student and passage predictors. Approximately 50% of variance in reading comprehension across students was explained by the student-level predictors, but only 18-22% of variance across items was explained by the passage-level and item-level predictors. Results from this study suggest that for Grade 3 readers, the strong predictive relations between student predictors of syntactic and vocabulary knowledge to reading comprehension may be moderated by some aspects of item and task demands. However, for this large-scale, multiple choice assessment of reading comprehension, variability in items and passages was largely unexplained. Results are discussed in the context of theoretical accounts of reading comprehension, from which the item and passage predictors are derived. / A Dissertation submitted to the School of Communication Science and Disorders in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester 2017. / July 26, 2017. / Florida Assessments for Instruction in Reading, grade three, item response modeling, multilevel modeling, reader-text interactions, reading comprehension / Includes bibliographical references. / Hugh W. Catts, Professor Directing Dissertation; Christopher Schatschneider, University Representative; Carla Wood, Committee Member; Donald Compton, Committee Member.

Bem-Estar Psicológico é um construto multidimensional baseado no funcionamento psicológico positivo. Para mensurar sua teoria, Ryff propôs uma escala de seis dimensões, com versões de 120, 84, 54 e 18 itens. Este trabalho tem como um de seus objetivos revisar sistematicamente estudos de validação das versões da Escala de Bem-Estar Psicológico de Ryff, sumarizando as propriedades psicométricas das mesmas. Foram incluídos estudos quantitativos que utilizaram a escala de Bem-Estar Psicológico, considerando as versões originais de 120, 84, 54 e 18 itens. Foram considerados elegíveis apenas os estudos sobre a validação da escala de Ryff em quaisquer versões e estudos com diferente número de itens oriundos das versões originais citadas anteriormente. Como estratégia de busca incluiu-se às bases de dados indexados Scopus e National Library of Medicine (Pubmed). A primeira estratégia de busca consistiu de palavras e descritores de Bem-Estar Psicológico. A segunda estratégia de busca adicionou palavras para especificar publicações na área de psicometria. Foram encontrados 38 artigos, totalizando 54 estudos, pois alguns artigos possuem mais de um estudo. A versão de 18 itens foi a mais validada, com 16 estudos, o espanhol foi a língua mais utilizada, a maioria dos artigos realizou análise fatorial e grande parte das amostras era composta por adultos com alto nível de escolaridade. O outro objetivo é realizar a análise fatorial exploratória com diferentes versões da Escala de Bem-estar Psicológico de Ryff de 18 itens e realizar a análise fatorial confirmatória com o modelo que apresentou melhor ajuste. Trata-se de um estudo transversal aninhado a uma coorte, cuja amostra foi de 389 idosos. Os dados desse estudo foram obtidos a partir da coorte de Carlos Barbosa que tinha como objetivo avaliar a saúde geral, bucal e psicológica e estado nutricional de idosos vivendo de maneira independente neste município. Foi realizada análise fatorial exploratória para avaliar a estrutura dimensional da escala de 18 itens e análise fatorial confirmatória para o modelo de melhor ajuste. Conclui-se que a escala de Bem-Estar Psicológico não é culturalmente dependente e que há necessidade de modificação de alguns itens para que o construto seja corretamente aplicado e compreendido na amostra estudada. / Psychological Well-Being is a multidimensional construct based on positive psychological functioning. To measure his theory, Ryff proposed a six-dimensional scale, with versions of 120, 84, 54, and 18 items. This work has as one of its objectives to systematically review validation studies of Ryff's Psychological Well-Being Scale versions, summarizing their psychometric properties. We included quantitative studies that used the Psychological Well-Being scale, considering the original versions of 120, 84, 54 and 18 items. Only studies on the validation of the Ryff scale in any versions and studies with different numbers of items from the original versions mentioned above were considered eligible. As a search strategy, the indexed databases Scopus and National Library of Medicine (Pubmed) were included. The first search strategy consisted of words and descriptors of Psychological Well-Being. The second search strategy added words to specify publications in the area of psychometrics. We found 38 articles, totaling 54 studies, once some articles have more than one study. The 18-item version was the most validated, with 16 studies, Spanish was the most used language, most of the articles performed factorial analysis and most of the samples were composed of adults with a high level of education. The other objective is to perform the exploratory factorial analysis with different versions of the Ryff’s Psychological Well-Being Scale of 18 items and perform the confirmatory factorial analysis with the model that presented the best fit. It is a cross-sectional study nested with a cohort, whose sample was 389 elderly. The data from this study were obtained from the Carlos Barbosa cohort whose objective was to evaluate the general, oral and psychological health and nutritional status of elderly people living independently in this municipality. An exploratory factorial analysis was performed to evaluate the dimensional structure of the 18-item scale and confirmatory factorial analysis for the best fit model. It is concluded that the Psychological Well-Being scale is not culturally dependent and that there is a need to modify some items so that the construct is correctly applied and understood in the sample studied.

Ringo M.H. Ho. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 75-81). / ACKNOWLEDGMENT --- p.2 / ABSTRACT --- p.3 / TABLE OF CONTENTS --- p.5 / LIST OF TABLES --- p.8 / Chapter CHAPTER 1 --- PREVIOUS STUDIES ON USING PROCRUSTES ROTATION TO ASSESS FACTORIAL INVARIANCE --- p.10 / Factorial invariance problem --- p.10 / Procrustes rotation with congruent coefficient as a way to test factorial invariance --- p.11 / Quantifying the Procrustes fit --- p.14 / Outline of the present study --- p.15 / Chapter CHAPTER 2 --- A CRITICAL EVALUATION OF THE PERMUTATION METHOD --- p.18 / Introduction --- p.18 / Method --- p.19 / Results and Discussions --- p.21 / Chapter CHAPTER 3 --- BOOTSTRAP TESTING PROCEDURE FOR A FULLY SPECIFIED TARGET --- p.24 / Introduction --- p.24 / A brief introduction to the bootstrap procedure --- p.24 / The bootstrap testing procedure for a fully specified target --- p.26 / Method --- p.28 / Results and Discussions --- p.28 / Chapter CHAPTER 4 --- BOOTSTRAP TESTING FOR A PARTIALLY SPECIFIED TARGET --- p.33 / Introduction --- p.33 / The bootstrap testing procedure for a partially specified target --- p.36 / Method --- p.38 / Quantifying the fit - congruence coefficients for the partial target rotation --- p.39 / Results and Discussions --- p.40 / Chapter CHAPTER 5 --- FURTHER EXTENSIONS OF THE BOOTSTRAP METHOD --- p.45 / Introduction --- p.45 / First extension - when correlation matrix is used --- p.45 / The modified bootstrap procedure --- p.45 / Method --- p.48 / Results and Discussions --- p.48 / Second extension - when raw data of the target sample is not available --- p.49 / The conditional bootstrap procedure for a fully specified target --- p.49 / Method --- p.50 / Results and Discussions --- p.51 / Chapter CHAPTER 6 --- THREE REAL EXAMPLES --- p.54 / Example 1 - Testing factorial invariance of CPAI between two random split samples --- p.54 / Results --- p.55 / Example 2 - Testing factorial invariance of CPAI between Chinese males and females --- p.56 / Results --- p.57 / Example 3 - Cross-cultural comparison of the Big Five Model between U. S. and Chinese samples --- p.58 / Results --- p.59 / Chapter CHAPTER 7 --- CONCLUSIONS --- p.62 / Practical remarks on the bootstrap procedure --- p.62 / A note on the transformation on the sample for constructing correct resampling space --- p.64 / Remarks on utilizing the congruence coefficients --- p.65 / How good are the congruence coefficients in detecting discrepancy between two factor structures? --- p.68 / Rule of thumb for factor congruence coefficient in checking factor replicability --- p.68 / Sample size requirement --- p.69 / Limitations of the present study --- p.70 / Direction of future studies --- p.71 / Concluding remarks --- p.73 / REFERENCES --- p.75 / NOTES --- p.82 / APPENDIX1 --- p.83 / TABLES 1 TO TABLES17 --- p.84

Apathy is characterised by a lack of motivation towards goal directed behaviour and is a symptom of various neurodegenerative diseases. There are various tools that can be used to assess apathy but a caveat of these is that they usually assess it as a unidimensional concept. Apathy has been recognised to have a multidimensional substructure. The Dimensional Apathy Scale is the only comprehensive measure designed to quantify neurobiologically-based subtypes, called Executive, Emotional and Initiation apathy. The first aim of this study was to explore multidimensional apathy, and its associations with demographic variables, in healthy, community dwelling adults. Secondly, multidimensional apathy was explored in neurodegenerative diseases, specifically Amyotrophic lateral sclerosis (ALS), Parkinson’s disease (PD) and Alzheimer’s disease (AD). For each disease group, the validity and reliability of both the self rated and carer rated DAS were also determined. Finally, the association between specific apathy subtype impairments and executive dysfunction was explored in ALS patients. Four hundred healthy community dwelling adults, eighty-three ALS patients (seventy-five carers), thirty-four PD patients (thirty carers) and forty-nine AD patients (eighty-nine carers) were recruited for the questionnaire study. In the healthy community dwelling adults, Executive apathy decreased with age, whereas Emotional increased with age. Gender differences were also shown with higher apathy in males on Emotional apathy. There were also employment differences, in that Executive apathy was higher in unemployed individuals compared to those who were employed. Emotional apathy showed difference in type of employment, where full time employed individuals were significantly more apathetic than those employed part time. These findings were taken into account in selecting the appropriate control samples to match our patient groups. In the patient groups, ALS patients were found to be significantly more impaired on the Initiation subscale when compared to controls. Furthermore, Initiation apathy was found to be the most frequent impairment above abnormality cut-off on the carer rated DAS. PD patients were significantly more impaired on Executive and Initiation apathy when compared to controls. These two subscales were most frequently above abnormality cut-off in the carer rated DAS. Finally, AD patients were significantly more impaired on all subscales when compared to controls and, on the carer rated DAS, global impairment over all subscales was most often reported as above abnormality cut-off. Additionally in AD, there was a significant disparity between carer and patient ratings on Executive and Initiation apathy, indicating patients’ impaired awareness. When comparing patient groups, there was a significant difference between carer rated apathy subtype impairments for each patient group. Validity and reliability of the DAS was found to be robust when compared to standard measures of apathy and depression. In the experimental study, a sample of ALS patients (and their carers) and healthy controls (and their informants) were recruited to complete a battery of neuropsychological tests, the DAS, other apathy and depression measures. ALS patients were impaired on tasks of executive functioning when compared to controls. Furthermore, apathy subtype deficits were associated with executive dysfunction in ALS. In conclusion, apathy is a multidimensional concept that manifests in different subtype profiles dependent on neurodegenerative disease. This has further implications for understanding and assessment of cognitive dysfunction and neuropsychiatric symptoms, such as apathy, in ALS and other neurodegenerative disease patient groups.

Academic writing is an important part of undergraduate study that tutors recognise as central to success in higher education. Across the academy, writing is used to assess, develop and facilitate student learning. However, there are growing concerns that students appropriate written work from other sources and present it as their own, committing the academic offence of plagiarism. Conceptualising plagiarism as literary theft, current institutional practices concentrate on deterring and detecting behaviours that contravene the rules of the academy. Plagiarism is a topic that often elicits an emotional response in academic tutors, who are horrified that students commit these ‘crimes’. Recently, educators have suggested that deterring and detecting plagiarism is ineffective and described moralistic conceptualisations of plagiarism as unhelpful. These commentaries highlight the need for credible alternative approaches to plagiarism that include pedagogic aspects of academic writing. The authorial identity approach to reducing plagiarism concentrates on developing understanding of authorship in students using pedagogy. This thesis presents three studies that contribute to the authorial identity approach to student plagiarism. Building on the findings of previous research, the current studies used a sequential mixed-methods approach to expand psychological knowledge concerning authorial identity in higher education contexts. The first, qualitative, study used thematic analysis of interviews with 27 professional academics teaching at institutions in the United Kingdom. The findings from this multidisciplinary sample identified that academics understood authorial identity as composed of five themes; an individual with authorial identity had confidence; valued writing; felt attachment and ownership of their writing; thought independently and critically; and had rhetorical goals. In addition, the analysis identified two integrative themes representing aspects of authorial identity that underlie all of the other themes: authorial identity as ‘tacit knowledge’ and authorial identity as ‘negotiation of identities’. The themes identified in the first study informed important aspects of the two following quantitative studies. The second study used findings from the first study to generate a pool of questionnaire items, assess their content validity and administer them to a multidisciplinary sample of 439 students in higher education. Psychometric analyses were used to identify a latent variable model of student authorial identity with three factors: ‘authorial confidence’, ‘valuing writing’ and ‘identification with author’. This model formed the basis of a new psychometric tool for measuring authorial identity. The resultant Student Attitudes and Beliefs about Authorship Scale (SABAS) had greater reliability and validity when compared with alternative measures. The third study used confirmatory factor analysis to validate the SABAS model with a sample of 306 students. In addition, this study identified aspects of convergent validity and test-retest reliability that allow the SABAS to be used with confidence in research and pedagogy. The overall findings of the combined studies present a psycho-social model of student authorial identity. This model represents an important contribution to the theoretical underpinnings of the authorial identity approach to student plagiarism. Differing from previous models by including social aspects of authorial identity, the psycho-social model informs future pedagogy development and research by outlining a robust, empirically supported theoretical framework.