How to handle missing data: A comparison of different approaches

Many researchers face the problem of missing data in longitudinal research. Especially, high risk samples are characterized by missing data which can complicate analyses and the interpretation of results. In the current study, our aim was to find the most optimal and best method to deal with the missing data in a specific study with many missing data on the outcome variable. Therefore, different techniques to handle missing data were evaluated, and a solution to efficiently handle substantial amounts of missing data was provided. A simulation study was conducted to determine the most optimal method to deal with the missing data. Results revealed that multiple imputation (MI) using predictive mean matching was the most optimal method with respect to lowest bias and the smallest confidence interval (CI) while maintaining power. Listwise deletion and last observation carried backward also scored acceptable with respect to bias; however, CIs were much larger and sample size almost halved using these methods. Longitudinal research in high risk samples could benefit from using MI in future research to handle missing data. The paper ends with a checklist for handling missing data.     

Pro- and Antisaccades: Dissociating Stimulus and Response Influences the Online Control of Saccade Trajectories

The authors examined whether the diminished online control of antisaccades is related to a trade-off between movement planning and control or the remapping of target properties to a mirror-symmetrical location (i.e., vector inversion). Pro- and antisaccades were examined in a standard no-delay schedule wherein target onset served as the movement imperative and a delay cuing schedule wherein responses were initiated 2,000 ms following target onset. Importantly, the delay cuing schedule was employed to equate pro- and antisaccade reaction times. Online control was evaluated by indexing the strength of trajectory amendments at normalized increments of movement time. Antisaccades exhibited fewer online corrections than prosaccades, and this result was consistent across cuing schedules. Thus, the diminished online control of antisaccades cannot be tied to a trade-off between movement planning and control. Rather, the authors propose that the intentional nature of dissociating stimulus and response (i.e., vector inversion) engenders a slow mode of cognitive control that is not optimized for fast oculomotor corrections.     

Disclosure of Tests and Raw Test Data to the Courts: A Need for Reform

Psychologists' current practices with respect to the disclosure of tests and raw test data to courts are damaging their reputations as scientists, undermining their credibility as honest professionals acting in good faith, and contrary to the best interests of consumers. The profession is conducting itself in a contradictory fashion that deserves reform. There is need for an interdisciplinary panel drawn from the American Psychological Association and American Bar Association to develop reasonable procedures for disclosure of tests and test data in legal proceedings. These procedures should be developed with input from experienced psychological expert witnesses, attorneys, and judges from a variety of state and federal jurisdictions, diverse geographical areas, and different types of legal proceedings. This expert panel should also address the issue of attorney coaching of clients in preparation for assessment by psychologists.     

Evaluating interobserver reliability of interval data

Previous recommendations to employ occurrence, nonoccurrence, and overall estimates of interobserver reliability for interval data are reviewed. A rationale for comparing obtained reliability to reliability that would result from a random-chance model is explained. Formulae and graphic functions are presented to allow for the determination of chance agreement for each of the three indices, given any obtained per cent of intervals in which a response is recorded to occur. All indices are interpretable throughout the range of possible obtained values for the per cent of intervals in which a response is recorded. The level of chance agreement simply changes with changing values. Statistical procedures that could be used to determine whether obtained reliability is significantly superior to chance reliability are reviewed. These procedures are rejected because they yield significance levels that are partly a function of sample sizes and because there are no general rules to govern acceptable significance levels depending on the sizes of samples employed.     

Reserve price and competing bids: Reference points for product evaluations in online auctions?

With an increasing number of products sold in online auctions, the effect of reference points on consumers' product valuations has received much attention in the literature. Two potentially relevant factors affecting bidders' preferences are the sellers' reserve price and the competing bids by other bidders. The current evidence regarding these reference points is mixed. We argue that a focus on studying bids prevents a clear identification of reference point effects. Directly observing product valuations, in two experiments, we find that willingness to pay in online auctions is affected by both reserve prices and competing bids, supporting the constructed values paradigm. Copyright © 2015 John Wiley & Sons, Ltd.     

La protection des données personnelles des patients face à la modernisation de notre système de santé

With the Internet and the artificial intelligence, the collection of personal data is becoming a strategic element for the digital economy. The collection of information touching the health or the body must respect the patients’ rights. The GDPR came into effect on May 25th, 2018. The healthcare professionals who are established in a Member state, must be careful because they can base their exercise on clinical or biological elements of their patients.     

An informal online learning community for student mental health at university: a preliminary investigation

As a potential solution to increasing demands on mental health services at universities, this project seeks to develop an informal online learning community for mental health support and education. Students' use of the Internet and Information and Communication Technologies (ICT), especially to access health information, provides a supporting rationale for this project. The design for this study is grounded in the pedagogical principles of informal learning and the practices for building successful online communities. The student online mental health community has been implemented at the authors' university (University of Dublin, Trinity College) for one academic term and the initial analysis of its usage is positive. Features that are being positively evaluated are the role of the reader participant, disinhibition that arises from anonymity, online provision acting as a gateway to further support, and online provision reaching an audience who ordinarily do not use face-to-face services. At the same time, difficulties specific to this type of community have surfaced, including technical issues, implications of anonymity and user safety.     

“Sherry’s Secret”

The case and commentaries below were developed as part of a project, Graduate Research Ethics Education, undertaken by the Association for Practical and Professional Ethics with funding from the National Science Foundation (NSF Grant No. SBR 9421897 and NSF Grant No. 9817880). The project aims at training graduate students in research ethics and building a community of scientists and engineers who are interested in and capable of teaching research ethics. As part of the project, each graduate student participant develops a case for use in teaching and writes a commentary to go with the case, and then a staff member is asked to write additional commentary on the case. The case below was written in the second year of the project and was published in Research Ethics: Cases and Commentaries edited by B. Schrag, Association for Practical and Professional Ethics, Bloomington, Indiana, Vol. II (1998). Publication of these cases and commentaries will be a recurring feature of Science and Engineering Ethics.     

The Short Mood and Feelings Questionnaire (SMFQ): A Unidimensional Item Response Theory and Categorical Data Factor Analysis of Self-Report Ratings from a Community Sample of 7-through 11-Year-Old Children

Item response theory (IRT) and categorical data factor analysis (CDFA) are complementary methods for the analysis of the psychometric properties of psychiatric measures that purport to measure latent constructs. These methods have been applied to relatively few child and adolescent measures. We provide the first combined IRT and CDFA analysis of a clinical measure (the Short Mood and Feelings Questionnaire—SMFQ) in a community sample of 7-through 11-year-old children. Both latent variable models supported the internal construct validity of a single underlying continuum of severity of depressive symptoms. SMFQ items discriminated well at the more severe end of the depressive latent trait. Item performance was not affected by age, although age correlated significantly with latent SMFQ scores suggesting that symptom severity increased within the age period of 7–11. These results extend existing psychometric studies of the SMFQ and confirm its scaling properties as a potential dimensional measure of symptom severity of childhood depression in community samples.     

Weighted least squares fitting using ordinary least squares algorithms

A general approach for fitting a model to a data matrix by weighted least squares (WLS) is studied. This approach consists of iteratively performing (steps of) existing algorithms for ordinary least squares (OLS) fitting of the same model. The approach is based on minimizing a function that majorizes the WLS loss function. The generality of the approach implies that, for every model for which an OLS fitting algorithm is available, the present approach yields a WLS fitting algorithm. In the special case where the WLS weight matrix is binary, the approach reduces to missing data imputation.This research has been made possible by a fellowship from the Royal Netherlands Academy of Arts and Sciences to the author.