Univariate Probability Distributions

We describe a web-based interactive graphic that can be used as a resource in introductory classes in mathematical statistics. This interactive graphic presents 76 common univariate distributions and gives details on (a) various features of the distribution such as the functional form of the probability density function and cumulative distribution function, graphs of the probability density function for various parameter settings, and values of population moments; (b) properties that the distribution possesses, for example, linear combinations of independent random variables from a particular distribution family also belong to the same distribution family; and (c) relationships between the various distributions, including special cases, transformations, limiting distributions, and Bayesian relationships. The interactive graphic went online on 11/30/12 at the URL www.math.wm.edu/ leemis/chart/UDR/UDR.html

Continuance and Satisfaction in Outpatient Psychotherapy: An Exploration of Patient and Treatment Variables

This study explored the effects of various patient, therapist and treatment variables on continuance and treatment satisfaction at an outpatient mental health center. One hundred patients who had terminated treatment between January 1, 1987 and March 31, 1989, were selected for study by stratified proportionate random sampling on the basis of the number of attended sessions. Patient variables included sociodemographic status, fees, degree of stress at time of intake, locus of control (external vs internal) and presenting problem causal attribution type (self, self-in-situation, environmental and situational). Therapist variables included age, gender, years of experience and professional discipline. Treatment variables were comprised of the patients' perceptions of the therapists' skills, the perceived quality of the professional relationship and the perception of concurrent logistical problems. The findings indicated that four variables contributed significantly to the variance in continuance; the quality of the professional relationship, the patient's degree of stress, social class and problem causal attribution type (multiple R² = .61, p ≤ .001). That is: patients who perceived the therapeutic relationship as a poor one, with low degrees of stress, who are from lower social classes, with problem causal attribution types of stimulus (other) or situation, were most likely to terminate within twelve sessions. Four variables were found to contribute significantly to the variance in overall satisfaction: perception of the professional's skills, the quality of the professional relationship, perception of a long initial wait for service and the ability to afford the fee (multiple R² = .83, p ≤ .001). That is: patients who perceived the professional's skills as ineffective, the quality of the professional relationship as a a poor or fair one, who felt they had initially waited too long for service and paid too high a fee, were most likely to be dissatisfied with the overall treatment experience. It was hypothesized that when the relationship between continuance and satisfaction was not a linear one; i.e., patients who dropped out after one session with high degrees of satisfaction, or patients who remained beyond twenty-five sessions with low degrees of satisfaction, the combination of variables for both continuance and satisfaction accounted for this phenomenon

Beliefs about 'stroke' and 'its effects': a study of their association with emotional distress

Emotional distress (symptoms of depression and anxiety) and emotional disorders are commonly experienced following stroke and negatively influence recovery and survival rates. Past research suggests that depressive symptoms are not directly related to lesion location and are only weakly related to actual functional and social losses. Patients' own subjective beliefs have been underresearched. This thesis was developed using cognitive theory, past research on emotional adaptation to emotional disability and observations from piloting. The main study aimed to investigate distress and a set of beliefs about 'stroke' and 'its effects', and to longitudinally test associations between specific beliefs and distress, taking into account relevant background variables. Supplementary studies aimed to explore emotional distress and disorder and relevant beliefs.A consecutive series of 89 patients, without severe cognitive or communication impairment, were interviewed one month (baseline) after admission to a stroke unit and 81 were interviewed again at nine months (follow-up).In the main study, distress was measured using global Hospital Anxiety and Depression scale scores. Specific beliefs about 'stroke' and 'its effects' investigated were: Attributions (Casual controllability, 'Why me?', 'Found meaning?'); Negative self-evaluations (Acceptance of disability, Negative identity change, Shame); Beliefs in recovery and recurrence (Recovery locus of control, Confidence in recovery, Recurrence fear). Background variables measured were: Demographics, Stroke severity, Disability, Pre-stroke depression, Social support and Life events.The first supplementary study used the structured clinical interview (SCID) for DSMIV to assess depressive disorder (major or minor) and common anxiety disorders (generalised anxiety disorder, agoraphobia, social phobia, post traumatic stress disorder) and, additionally, as a means for exploring relevant beliefs. The second supplementary study involved further qualitative interviews with sixty participants at baseline to explore their own experiences and main concerns.Associations were found between distress and most belief variables at baseline, follow-up and across time. Backward linear regression analyses for distress were used to study belief variables taking background variables into account. At baseline and follow-up these analyses supported the statistical significance of associations between distress and negative self-evaluative beliefs and recurrence fear. Across time, a role for causal controllability and acceptance of disability was supported. However, these results also highlighted the pervasive influence of a pre-stroke history of depression and of initial distress levels across time.The SCID interview identified that many patients met criteria for depressive disorder (33% at one and 30% at nine months) or anxiety disorder (35% at one and 33% at nine months) but also yielded information regarding specific stroke-related beliefs relevant to distress versus adaptation. The qualitative interviews provided insight into patients' idiosyncratic concerns. This extended the main findings, for example by illustrating the varied nature of recurrence fear beliefs and highlighting individuals' needs to give as well as receive social support.The SCID interview identified that many patients met criteria for depressive disorder (33% at one and 30% at nine months) or anxiety disorder (35% at one and 33% at nine months) but also yielded information regarding specific stroke-related beliefs relevant to distress versus adaptation. The qualitative interviews provided insight into patients' idiosyncratic concerns. This extended the main findings, for example by illustrating the varied nature of recurrence fear beliefs and highlighting individuals' needs to give as well as receive social support.Emotional distress (symptoms of depression and anxiety) and emotional disorders are commonly experienced following stroke and negatively influence recovery and survival rates. Past research suggests that depressive symptoms are not directly related to lesion location and are only weakly related to actual functional and social losses. Patients' own subjective beliefs have been underresearched. This thesis was developed using cognitive theory, past research on emotional adaptation to emotional disability and observations from piloting. The main study aimed to investigate distress and a set of beliefs about 'stroke' and 'its effects', and to longitudinally test associations between specific beliefs and distress, taking into account relevant background variables. Supplementary studies aimed to explore emotional distress and disorder and relevant beliefs.A consecutive series of 89 patients, without severe cognitive or communication impairment, were interviewed one month (baseline) after admission to a stroke unit and 81 were interviewed again at nine months (follow-up).In the main study, distress was measured using global Hospital Anxiety and Depression scale scores. Specific beliefs about 'stroke' and 'its effects' investigated were: Attributions (Casual controllability, 'Why me?', 'Found meaning?'); Negative self-evaluations (Acceptance of disability, Negative identity change, Shame); Beliefs in recovery and recurrence (Recovery locus of control, Confidence in recovery, Recurrence fear). Background variables measured were: Demographics, Stroke severity, Disability, Pre-stroke depression, Social support and Life events.The first supplementary study used the structured clinical interview (SCID) for DSMIV to assess depressive disorder (major or minor) and common anxiety disorders (generalised anxiety disorder, agoraphobia, social phobia, post traumatic stress disorder) and, additionally, as a means for exploring relevant beliefs. The second supplementary study involved further qualitative interviews with sixty participants at baseline to explore their own experiences and main concerns.Associations were found between distress and most belief variables at baseline, follow-up and across time. Backward linear regression analyses for distress were used to study belief variables taking background variables into account. At baseline and follow-up these analyses supported the statistical significance of associations between distress and negative self-evaluative beliefs and recurrence fear. Across time, a role for causal controllability and acceptance of disability was supported. However, these results also highlighted the pervasive influence of a pre-stroke history of depression and of initial distress levels across time.The SCID interview identified that many patients met criteria for depressive disorder (33% at one and 30% at nine months) or anxiety disorder (35% at one and 33% at nine months) but also yielded information regarding specific stroke-related beliefs relevant to distress versus adaptation. The qualitative interviews provided insight into patients' idiosyncratic concerns. This extended the main findings, for example by illustrating the varied nature of recurrence fear beliefs and highlighting individuals' needs to give as well as receive social support.This study provides qualified support for cognitive theory of distress following stroke by demonstrating associations between distress and beliefs concerning 'stroke' and 'its effects' in the short- and longer-term aftermath of stroke. Over and above measures of disability, a personal sense of being unable to accept reduced capability, which some went so far to describe as 'uselessness', was related to higher levels of distress and disorder. Fear of recurrent stroke was common. Belief in the controllability of risk factors tended to be low; however a greater initial sense of causal controllability appeared protective against distress across time. These results have implications for the development of interventions to address the high prevalence of emotional distress and disorder following stroke

Using SPSS to Understand Research and Data Analysis

https://scholar.valpo.edu/psych_oer/1000/thumbnail.jp

An investigation of firm specific and macroeconomic variables and their influence on emerging market stock returns

Includes bibliographical references.This paper aims to expand on the growing area of asset pricing research in developed markets by extending such analyses to those nations considered to be emerging. Of late the accuracy of a previously established cornerstone of asset pricing theory, namely the Capital Asset Pricing Model (CAPM) has been questioned. The discovery of numerous firm related anomalies that have predictive power over the cross sectional variation of share returns in excess of that explained by established market proxy models has served to fuel interest and speculation as to the true robustness and exploitability of such influences. These firm specific influences have been termed 'style characteristics' . This study employed the use of the DataStream International Emerging Market Index for the extraction of all firm specific and return data. In addition to the considered 'style' characteristics this study explores the broader systematic effects associated with changes in key macroeconomic variables

Comparison of Flickr and Public Participation GIS to characterise the types, spatial patterns and socio-ecological drivers of social values for the Kimberley region

Coastal and marine environments are highly valued for the resources and services they provide. To sustainably manage these environments, we need to understand what people value and where these values occur, but spatial data is not always easily obtainable. Crowdsourcing methods such as the retrieval of geotagged photographs from the photo-sharing social media platform Flickr and Public Participation GIS (PPGIS) that use field-based or online mapping techniques enable the identification, quantification and mapping of social values. This study compared these methods to evaluate whether Flickr provides similar data to PPGIS about values and where they are likely to occur. A total of 5,293 geotagged Flickr photographs of the natural environment were retrieved for the Kimberley region in Western Australia. The relative abundance of the ten evaluated value types differed between Flickr and two previously published PPGIS datasets involving field-based interviews (p < 0.001) and an online survey (p < 0.001), but scenic/aesthetic and nature appreciation were highly valued in all studies. There were clear distinctions in the spatial patterns of where values were recorded; Flickr users tended to take photographs near easily-accessible locations, whereas PPGIS participants mapped values across most of the Kimberley coastline. Spatial modelling performed to investigate the distribution of value types revealed accessibility was the main driver to where Flickr users were likely to take photographs within the Kimberley region. In contrast, values mapped by PPGIS participants were more broadly distributed and therefore the models were less able to identify strong relationships with the evaluated drivers. Despite this, value types mapped by both methods were concentrated near the coastline and the few major towns of the region, likely due to these being familiar places and popular tourism destinations. Values crowdsourced through Flickr and PPGIS can be used together to take advantage of their reinforcing and complementary information. Whilst PPGIS enabled more value types to be identified within the study area and over a greater spatial distribution, Flickr can be used to provide further depth of information, such as insight into certain value types through photograph content analysis and by highlighting locations of visitation that may need management. The findings of this study can be valuable to inform future planning and management of coastal and marine environments, especially where spatial data may be limited