1,379 research outputs found
Scatteract: Automated extraction of data from scatter plots
Charts are an excellent way to convey patterns and trends in data, but they
do not facilitate further modeling of the data or close inspection of
individual data points. We present a fully automated system for extracting the
numerical values of data points from images of scatter plots. We use deep
learning techniques to identify the key components of the chart, and optical
character recognition together with robust regression to map from pixels to the
coordinate system of the chart. We focus on scatter plots with linear scales,
which already have several interesting challenges. Previous work has done fully
automatic extraction for other types of charts, but to our knowledge this is
the first approach that is fully automatic for scatter plots. Our method
performs well, achieving successful data extraction on 89% of the plots in our
test set.Comment: Submitted to ECML PKDD 2017 proceedings, 16 page
Changing the ideological roots of prejudice: Longitudinal effects of ethnic intergroup contact on social dominance orientation
Social Dominance Orientation (SDO) has been reported to be strongly related to a multitude of intergroup phenomena, but little is known about situational experiences that may influence SDO. Drawing from research on intergroup contact theory, we argue that positive intergroup contact is able to reduce SDO-levels. The results of an intergroup contact intervention study among high school students (Study 1, N=71) demonstrated that SDO-levels were indeed attenuated after the intervention. Furthermore, this intervention effect on SDO was especially pronounced among students reporting a higher quality of contact. A cross-lagged longitudinal survey among adults (Study 2, N=363) extended these findings by demonstrating that positive intergroup contact is able to decrease SDO over time. Moreover, we did not obtain evidence for the idea that people high in SDO would engage less in intergroup contact. These findings indicate that intergroup contact erodes one of the important socio-ideological bases of generalized prejudice and discrimination
Parenting for Lifelong Health for young children: a randomized controlled trial of a parenting program in South Africa to prevent harsh parenting and child conduct problems
Background:
Parenting programs suitable for delivery at scale in low‐resource contexts are urgently needed. We conducted a randomized trial of Parenting for Lifelong Health (PLH) for Young Children, a low‐cost 12‐session program designed to increase positive parenting and reduce harsh parenting and conduct problems in children aged 2–9.
Methods:
Two hundred and ninety‐six caregivers, whose children showed clinical levels of conduct problems (Eyberg Child Behavior Inventory Problem Score, >15), were randomly assigned using a 1:1 ratio to intervention or control groups. At t0, and at 4–5 months (t1) and 17 months (t2) after randomization, research assistants blind to group assignment assessed (through caregiver self‐report and structured observation) 11 primary outcomes: positive parenting, harsh parenting, and child behavior; four secondary outcomes: parenting stress, caregiver depression, poor monitoring/supervision, and social support. Trial registration: ClinicalTrials.gov (NCT02165371); Pan African Clinical Trial Registry (PACTR201402000755243); Violence Prevention Trials Register (http://www.preventviolence.info/Trials?ID=24).
Results:
Caregivers attended on average 8.4 sessions. After adjustment for 30 comparisons, strongest results were as follows: at t1, frequency of self‐reported positive parenting strategies (10% higher in the intervention group, p = .003), observed positive parenting (39% higher in the intervention group, p = .003), and observed positive child behavior (11% higher in the intervention group, p = .003); at t2, both observed positive parenting and observed positive child behavior were higher in the intervention group (24%, p = .003; and 17%, p = .003, respectively). Results with p‐values < .05 prior to adjustment were as follows: At t1, the intervention group self‐reported 11% fewer child problem behaviors, 20% fewer problems with implementing positive parenting strategies, and less physical and psychological discipline (28% and 14% less, respectively). There were indications that caregivers reported 20% less depression but 7% more parenting stress at t1. Group differences were nonsignificant for observed negative child behavior, and caregiver‐reported child behavior, poor monitoring or supervision, and caregiver social support.
Conclusions:
PLH for Young Children shows promise for increasing positive parenting and reducing harsh parenting
Putting theory oriented evaluation into practice
Evaluations of gaming simulations and business games as teaching devices are typically end-state driven. This emphasis fails to detect how the simulation being evaluated does or does not bring about its desired consequences. This paper advances the use of a logic model approach which possesses a holistic perspective that aims at including all elements associated with the situation created by a game. The use of the logic model approach is illustrated as applied to Simgame, a board game created for secondary school level business education in six European Union countries
How can we evaluate the effectiveness of grammar schools in England? A regression discontinuity approach
Previous research evaluating grammar school effectiveness has generally relied on snapshot or longitudinal regression models to deal with pre‐existing differences between grammar school pupils and those in non‐selective schools. These passive designs are based on correlations, and cannot demonstrate clear positive causal relationships between grammar school attendance and subsequent attainment. After accounting for the variables available for the analysis, pupils in different schools might still have distinct and unmeasured characteristics which threaten the validity of any conclusions drawn. Given that a randomised trial is not feasible under current conditions, this study addresses the limitations of previous research, using a regression discontinuity design (RDD) approach. This is the first use of RDD to attempt to make a robust causal inference about the effectiveness of grammar schools in one local authority in England. However, the authority, the Department for Education and the schools would not provide the individual data on pupils’ 11+ entry test scores, and the scores obtained could not be uniquely matched to Key Stage 4 outcomes. While the model presented suggests that there is an advantage to grammar school attendance, the incomplete data means that the study is more a feasibility trial of this strong design than any kind of definitive test intended to settle the debate on grammar school effectiveness. Conducting this design with national data on grammar school selection would create the most powerful evidence so far. To promote an effective and equitable education system for generations to come, those advocating the expansion of grammar schools should make the responsible decision to disclose all grammar school selection data for the purposes of research
Validación de un documento de Word bajo la norma NTC1486 a partir de la metadata
Investigación TecnológicaEn el presente documento se encuentra contemplado el fundamento teórico de los tipos de datos y de los modelos de datos que se manejan en la actualidad, así como la web semántica y aspectos de ingeniería de software requeridos para la construcción de un prototipo de software que automatice el proceso de extracción de metadatos en un documento de Word, validando que la información contenida en este cumpla con la NTC 1486 en su totalidad, siendo una herramienta que facilite el proceso de calificación y caracterización de trabajos de grado y documentos de tipo investigativo. Esta investigación tiene un impacto dentro de la comunidad investigativa en la medida en que genera un prototipo de software que facilita el proceso de revisión de documentos investigativos en construcción.Glosario RESUMEN INTRODUCCIÓN 1.JUSTIFICACIÓN
2. PLANTEAMIENTO DEL PROBLEMA
3. OBJETIVO GENERAL
4. MARCO TEÓRICO
5. MARCO CONCEPTUAL
6. ESTADO DEL ARTE
7. METODOLOGÍA
8. RESULTADOS
9. CONCLUSIONES
10. TRABAJOS FUTUROS
11. BIBLIOGRAFÍAPregradoIngeniero de Sistema
Factors associated with dropout during recruitment and follow-up periods of a mHealth-based randomized controlled trial for Mobile.Net to encourage treatment adherence for people with serious mental health problems
Background: Clinical trials are the gold standard of evidence-based practice. Still many papers inadequately report methodology in randomized controlled trials (RCTs), particularly for mHealth interventions for people with serious mental health problems. To ensure robust enough evidence, it is important to understand which study phases are the most vulnerable in the field of mental health care.
Objective: We mapped the recruitment and the trial follow-up periods of participants to provide a picture of the dropout predictors from a mHealth-based trial. As an example, we used a mHealth-based multicenter RCT, titled “Mobile.Net,” targeted at people with serious mental health problems.
Methods: Recruitment and follow-up processes of the Mobile.Net trial were monitored and analyzed. Recruitment outcomes were recorded as screened, eligible, consent not asked, refused, and enrolled. Patient engagement was recorded as follow-up outcomes: (1) attrition during short message service (SMS) text message intervention and (2) attrition during the 12-month follow-up period. Multiple regression analysis was used to identify which demographic factors were related to recruitment and retention.
Results: We recruited 1139 patients during a 15-month period. Of 11,530 people screened, 36.31% (n=4186) were eligible. This eligible group tended to be significantly younger (mean 39.2, SD 13.2 years, P<.001) and more often women (2103/4181, 50.30%) than those who were not eligible (age: mean 43.7, SD 14.6 years; women: 3633/6514, 55.78%). At the point when potential participants were asked to give consent, a further 2278 refused. Those who refused were a little older (mean 40.2, SD 13.9 years) than those who agreed to participate (mean 38.3, SD 12.5 years; t1842=3.2, P<.001). We measured the outcomes after 12 months of the SMS text message intervention. Attrition from the SMS text message intervention was 4.8% (27/563). The patient dropout rate after 12 months was 0.36% (4/1123), as discovered from the register data. In all, 3.12% (35/1123) of the participants withdrew from the trial. However, dropout rates from the patient survey (either by paper or telephone interview) were 52.45% (589/1123) and 27.8% (155/558), respectively. Almost all participants (536/563, 95.2%) tolerated the intervention, but those who discontinued were more often women (21/27, 78%; P=.009). Finally, participants’ age (P<.001), gender (P<.001), vocational education (P=.04), and employment status (P<.001) seemed to predict their risk of dropping out from the postal survey.
Conclusions: Patient recruitment and engagement in the 12-month follow-up conducted with a postal survey were the most vulnerable phases in the SMS text message-based trial. People with serious mental health problems may need extra support during the recruitment process and in engaging them in SMS text message-based trials to ensure robust enough evidence for mental health care
Web-based alcohol intervention:study of systematic attrition of heavy drinkers
Background: Web-based alcohol interventions are a promising way to reduce alcohol consumption because of their anonymity and the possibility of reaching a high numbers of individuals including heavy drinkers. However, Web-based interventions are often characterized by high rates of attrition. To date, very few studies have investigated whether individuals with higher alcohol consumption show higher attrition rates in Web-based alcohol interventions as compared with individuals with lower alcohol consumption. Objectives: The aim of this study was to examine the attrition rate and predictors of attrition in a Web-based intervention study on alcohol consumption. Methods: The analysis of the predictors of attrition rate was performed on data collected in a Web-based randomized control trial. Data collection took place at the University of Konstanz, Germany. A total of 898 people, which consisted of 46.8% males (420/898) and 53.2% females (478/898) with a mean age of 23.57 years (SD 5.19), initially volunteered to participate in a Web-based intervention study to reduce alcohol consumption. Out of the sample, 86.9% (781/898) were students. Participants were classified as non-completers (439/898, 48.9%) if they did not complete the Web-based intervention. Potential predictors of attrition were self-reported: alcohol consumption in the last seven days, per week, from Monday to Thursday, on weekends, excessive drinking behavior measured with the Alcohol Use Disorder Identification Test (AUDIT), and drinking motives measured by the Drinking Motive Questionnaire (DMQ-R SF). Results: Significant differences between completers and non-completers emerged regarding alcohol consumption in the last seven days (B=-.02, P=.05, 95% CI [0.97-1.00]), on weekends (B=-.05, P=.003, 95% CI [0.92-0.98]), the AUDIT (B=-.06, P=.007, 95% CI [0.90-0.98], and the status as a student (B=.72, P=.001, 95% CI [1.35-3.11]). Most importantly, non-completers had a significantly higher alcohol consumption compared with completers. Conclusions: Hazardous alcohol consumption appears to be a key factor of the dropout rate in a Web-based alcohol intervention study. Thus, it is important to develop strategies to keep participants who are at high risk in Web-based interventions
Within study comparisons and risk of bias in international development: Systematic review and critical appraisal
Background Many systematic reviews incorporate nonrandomised studies of effects, sometimes called quasi‐experiments or natural experiments. However, the extent to which nonrandomised studies produce unbiased effect estimates is unclear in expectation or in practice. The usual way that systematic reviews quantify bias is through “risk of bias assessment” and indirect comparison of findings across studies using meta‐analysis. A more direct, practical way to quantify the bias in nonrandomised studies is through “internal replication research”, which compares the findings from nonrandomised studies with estimates from a benchmark randomised controlled trial conducted in the same population. Despite the existence of many risks of bias tools, none are conceptualised to assess comprehensively nonrandomised approaches with selection on unobservables, such as regression discontinuity designs (RDDs). The few that are conceptualised with these studies in mind do not draw on the extensive literature on internal replications (within‐study comparisons) of randomised trials. Objectives Our research objectives were as follows: Objective 1: to undertake a systematic review of nonrandomised internal study replications of international development interventions. Objective 2: to develop a risk of bias tool for RDDs, an increasingly common method used in social and economic programme evaluation. Methods We used the following methods to achieve our objectives. Objective 1: we searched systematically for nonrandomised internal study replications of benchmark randomised experiments of social and economic interventions in low‐ and middle‐income countries (L&MICs). We assessed the risk of bias in benchmark randomised experiments and synthesised evidence on the relative bias effect sizes produced by benchmark and nonrandomised comparison arms. Objective 2: We used document review and expert consultation to develop further a risk of bias tool for quasi‐experimental studies of interventions (ROBINS‐I) for RDDs. Results Objective 1: we located 10 nonrandomised internal study replications of randomised trials in L&MICs, six of which are of RDDs and the remaining use a combination of statistical matching and regression techniques. We found that benchmark experiments used in internal replications in international development are in the main well‐conducted but have “some concerns” about threats to validity, usually arising due to the methods of outcomes data collection. Most internal replication studies report on a range of different specifications for both the benchmark estimate and the nonrandomised replication estimate. We extracted and standardised 604 bias coefficient effect sizes from these studies, and present average results narratively. Objective 2: RDDs are characterised by prospective assignment of participants based on a threshold variable. Our review of the literature indicated there are two main types of RDD. The most common type of RDD is designed retrospectively in which the researcher identifies post‐hoc the relationship between outcomes and a threshold variable which determines assignment to intervention at pretest. These designs usually draw on routine data collection such as administrative records or household surveys. The other, less common, type is a prospective design where the researcher is also involved in allocating participants to treatment groups from the outset. We developed a risk of bias tool for RDDs. Conclusions Internal study replications provide the grounds on which bias assessment tools can be evidenced. We conclude that existing risk of bias tools needs to be further developed for use by Campbell collaboration authors, and there is a wide range of risk of bias tools and internal study replications to draw on in better designing these tools. We have suggested the development of a promising approach for RDD. Further work is needed on common methodologies in programme evaluation, for example on statistical matching approaches. We also highlight that broader efforts to identify all existing internal replication studies should consider more specialised systematic search strategies within particular literatures; so as to overcome a lack of systematic indexing of this evidence
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