Illustrating psychometric tests, scales, and constructs: An R package for Item Pool Visualization.

Researchers assessing psychological constructs have to understand and choose between several competing measures. Item Pool Visualization (IPV, Dantlgraber et al., 2019) was developed to offer a systematic and detailed portrayal of the actual content and internal balance of competing measures. To enable the use of IPV, we developed and present here the IPV R package. Its aim is to allow researchers to add IPV to their repertoire with minimal effort. Creating IPV charts from raw data requires two simple function calls, because the package streamlines model specification, model estimation, and chart creation. It improves IPV conceptually by introducing the aggregate center distance and the item overview chart. It provides many customization options and generates high-quality, vector-based PDF output. The workflow of the package is explained using a reproducible open data example from a personality assessment.

Functional neurological symptoms are a frequent and relevant comorbidity in patients with multiple sclerosis.

Introduction: Functional neurological symptoms (FNS) in multiple sclerosis (MS) have shown to be underinvestigated even though neurological diseases such as MS represent a risk factor for developing FNS. Comorbidity of FNS and MS can produce high personal and social costs since FNS patients have high healthcare utilization costs and a quality of life at least as impaired as in patients with disorders with underlying structural pathology. This study aims to assess comorbid FNS in patients with MS (pwMS) and investigate whether FNS in pwMS are associated with poorer health-related quality of life and work ability. Methods: Newly admitted patients (234) with MS were studied during their stay at Kliniken Schmieder, a neurological rehabilitation clinic in Konstanz, Germany. The degree to which the overall clinical picture was explained by MS pathology was rated by neurologists and allied health practitioners on a five-point Likert scale. Additionally, neurologists rated each symptom reported by the patients. Health-related quality of life was assessed using a self-report questionnaire and work ability was assessed using the mean number of hours worked per day and information regarding disability pension as reported by patients. Results: In 55.1% of cases, the clinical picture was completely explained by structural pathology due to MS. 17.1% of pwMS presented an overall clinical picture half or less of which could be explained by underlying structural pathology. PwMS with a higher comorbid FNS burden had a lower health-related quality of life and reported fewer working hours per day than pwMS with symptoms explained by structural pathology. Furthermore, pwMS with a full disability pension had a higher comorbid FNS burden than pwMS with no or partial disability pension. Discussion: These results show that FNS should be addressed diagnostically and therapeutically since such symptoms are an important comorbidity in MS that is related to poorer health-related quality of life and lower work ability.

Conceptual fluency in inductive reasoning.

Psychological effects connected with fluent processing are called fluency effects. In a sample of 403 participants we test whether conceptual fluency effects can be found in the context of inductive reasoning, a context that has not been investigated before. As a conceptual manipulation we vary the use of symbols (persons and crosses) in reasoning tasks. These symbols were chosen to provide hints for the solution of the implemented tasks and thus manipulate fluency. We found evidence that these hints influence ease of processing. The proportion of solved tasks increased by 11% on average in the condition with conceptual hints, F(1,399) = 13.47, partial η2 = .033, p < .001. However, we did not find an effect of the conceptual manipulation on the temporal perception of the task. In a second study (n = 62) we strengthened our findings by investigating solution strategies for the tasks in more detail, 79% of the participants described the tasks in a way they were intended. Our results illustrate the advantages of the separation of ease of processing, fluency experience, and judgments.

Investigating measurement equivalence of visual analogue scales and Likert-type scales in Internet-based personality questionnaires.

Visual analogue scales (VASs) have shown superior measurement qualities in comparison to traditional Likert-type response scales in previous studies. The present study expands the comparison of response scales to properties of Internet-based personality scales in a within-subjects design. A sample of 879 participants filled out an online questionnaire measuring Conscientiousness, Excitement Seeking, and Narcissism. The questionnaire contained all instruments in both answer scale versions in a counterbalanced design. Results show comparable reliabilities, means, and SDs for the VAS versions of the original scales, in comparison to Likert-type scales. To assess the validity of the measurements, age and gender were used as criteria, because all three constructs have shown non-zero correlations with age and gender in previous research. Both response scales showed a high overlap and the proposed relationships with age and gender. The associations were largely identical, with the exception of an increase in explained variance when predicting age from the VAS version of Excitement Seeking (B10 = 1318.95, ΔR(2) = .025). VASs showed similar properties to Likert-type response scales in most cases.

Simple construct evaluation with latent class analysis: An investigation of Facebook addiction and the development of a short form of the Facebook Addiction Test (F-AT).

In psychological research, there is a growing interest in using latent class analysis (LCA) for the investigation of quantitative constructs. The aim of this study is to illustrate how LCA can be applied to gain insights on a construct and to select items during test development. We show the added benefits of LCA beyond factor-analytic methods, namely being able (1) to describe groups of participants that differ in their response patterns, (2) to determine appropriate cutoff values, (3) to evaluate items, and (4) to evaluate the relative importance of correlated factors. As an example, we investigated the construct of Facebook addiction using the Facebook Addiction Test (F-AT), an adapted version of the Internet Addiction Test (I-AT). Applying LCA facilitates the development of new tests and short forms of established tests. We present a short form of the F-AT based on the LCA results and validate the LCA approach and the short F-AT with several external criteria, such as chatting, reading newsfeeds, and posting status updates. Finally, we discuss the benefits of LCA for evaluating quantitative constructs in psychological research.