Some Relationships Between Cronbach's Alpha and the Spearman-Brown Formula

Cronbach's alpha is an estimate of the reliability of a test score if the items are essentially tau-equivalent. Several authors have derived results that provide alternative interpretations of alpha. These interpretations are also valid if essential tau-equivalency does not hold. For example, alpha is the mean of all split-half reliabilities if the test is split into two halves that are equal in size. This note presents several connections between Cronbach's alpha and the Spearman-Brown formula. The results provide new interpretations of Cronbach's alpha, the stepped down alpha, and standardized alpha, that are also valid in the case that essential tau-equivalency or parallel equivalency do not hold. The main result is that the stepped down alpha is a weighted average of the alphas of all subtests of a specific size, where the weights are the denominators of the subtest alphas. Thus, the stepped down alpha can be interpreted as an average subtest alpha. Furthermore, we may calculate the stepped down alpha without using the Spearman-Brown formula

Plataforma Moodle y actitud hacia el aprendizaje de las matemáticas, en estudiantes de una universidad privada, Lima, 2020

El presente trabajo de investigación tuvo como objetivo principal determinar cómo se relacionan el uso de la plataforma Moodle y la actitud hacia el aprendizaje de las matemáticas, en estudiantes de una Universidad Privada, Lima, 2020. Para ello, se realizó el estudio de la variable uso de la plataforma Moodle, que cuenta con las dimensiones de herramientas de aprendizaje, herramientas de comunicación y herramientas de productividad. Así mismo, se investigó sobre la variable actitud hacia el aprendizaje de las matemáticas y sus dimensiones actitud hacia el aprendizaje cognitivo, actitud hacia el aprendizaje afectivo y actitud hacia el aprendizaje conductual. La investigación desarrollada fue de tipo básica y enfoque cuantitativo. El nivel fue correlacional y el diseño no experimental descriptivo, de corte transversal. La población fue 98 estudiantes, con lo cual se obtuvo como muestra 78 estudiantes de la carrera de ingeniería de sistemas e informática matriculados en el curso de Matemática I y el muestreo fue aleatorio simple. La técnica empleada para la recolectar datos fue la encuesta y el instrumento fue el cuestionario. Luego de realizada la recolección de datos, se tuvo como resultados descriptivos que el uso de la plataforma Moodle se encuentra en un nivel regular, en un 37, 2%. Así mismo, la actitud hacia el aprendizaje de las matemáticas se encuentra en un nivel desfavorable, en un 59%. En cuanto al análisis inferencial, se concluye que existe relación en un grado positivo alto entre el uso de la plataforma Moodle y la actitud hacia el aprendizaje de las matemáticas, lo cual se verifica con el nivel de significancia de 0,00<0,05 y el coeficiente de correlación de Spearman de 0,801

Leadership Characteristics of Protective Force Instructors

The National Nuclear Security Administration, the governmental agency responsible for safeguarding and security the United States’ nuclear weapons production and research facilities, employs an armed protective force that responds to the full spectrum of threats. Governmental reports previously identified protective force performance in need of improvement. The purpose of this quantitative study, through the use of correlational research, is to identify the beneficial leadership characteristics of instructors, from the full range of leadership model, that enhance training and increase officer performance during training and improve mission performance. The Multifactor Leadership Questionnaire (MLQ) was used to identify instructor leadership characteristics and student outcomes. Consistent with previous research results, transformational leadership had a stronger significant positive relationship with student outcomes than transactional and passive-avoidant leadership

The Relationship Between Information Quality and Construction Safety

Fatal occupational injury is a construction and management problem in the United States. Fatality rates among specialty trade contractors made up the largest percent of fatalities in construction at 62% per year. The purpose of this nonexperimental study was to examine the relationship between the quality of information in construction safety plans and construction safety among specialty trade contractors. The theoretical foundations for the study were Petersen\u27s accident/incident theory and work systems theory. The key research question was to examine the relationship between information quality and construction safety among specialty trade contractors. A survey with closed-ended questions was used to collect primary data from a self-selection sample of 134 specialty trade contractors in the United States. Spearman rank correlation coefficient (rs) was used to measure the strength of the relationship between information quality and construction safety. Results indicated that the quality of information in construction safety plans (measured by the relevance, accuracy, timeliness, and completeness of information) did not have any statistically significant relationships with construction safety among U.S. specialty trade contractors. Further research is needed to understand if the variables used in this study are relevant predictors for construction safety. This study connects with positive social change by bringing into focus quality information systems research required to improve safety among U.S. specialty trade contractors and provide safety professionals a direction for continuous safety improvement in the U.S. construction industry, thus benefitting construction stake holders