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The aim of the study was to assess the effects of high concentrations (10 % w/w, data projected for 2030) of commercial bioplastics, i.e. starch based shopping bags (SBSB) and polylactic acid (PLA) tableware, in the organic fraction of municipal solid wastes (MSW) on compost quality obtained by pilot-scale dry mesophilic anaerobic digestion and subsequent composting of the digestate. After the biological processes, 48.1 % total solids (TS) of SBSB and 15 % TS of PLA degraded, resulting in a high bioplastics content (about 18 % TS) in compost. Subsequent compost incubation in soils indicated that bioplastics degraded by pseudo-zero order kinetics (0.014 and 0.010 mg C cm−2 d-1 for SBSB and PLA, respectively), i.e. complete degradation was expected in 1.6 years (SBSB) and 7.2 years (PLA), confirming the intrinsic biodegradability of bioplastics. Nevertheless, enhancing the rate and amount of bioplastics degradation during waste management represents a goal to decrease the amount of bioplastics reaching the environment.

The aim of this study is to characterize the digestates from three plastic tubular digesters implemented in Colombia fed with: i) cattle manure; ii) cattle manure mixed with cheese whey; iii) pig manure. All the digesters worked under psychrophilic conditions. Physico-chemical characteristics, heavy metals, pathogens, and agronomic quality were investigated. All the digestates were characterized by physico-chemical characteristics and nutrients concentration suitable for their reuse as biofertilizer. However, these digestates may only partially replace a mineral fertilizer due to the high nutrients dilution. Heavy metals were under the detection limit of the analytical method (Pb, Hg, Ni, Mo, Cd, Chromium VI) or present at low concentration (Cu, Zn, As, Se) in all the digestates. Biodegradable organic matter and pathogens (coliform, helminths and Salmonella spp.) analysis proved that all the digestates should be post-treated before soil application in order to prevent environmental and health risks, and also to reduce residual phytotoxicity effects. The digestate from pig manure had a higher nutrient percentage (0.2, 0.6 and 0.05 % w/w of total N, P2O5 and K2O, respectively), but also higher residual phytotoxicity than the other digestates. Co-digestion seemed not to significantly improve the digestate fertilizing potential. Finally, further studies should address how to improve fertilizing potential of digestates from plastic tubular digesters, avoiding environmental and health risks. This research was funded by the Centre for Development Cooperation, Universitat Politècnica de Catalunya·BarcelonaTech (Project CCD2018-U003) and the Universidad Industrial de Santander, Colombia (Jerarquización de alternativas de gestión y valorización de digeridos anaerobios provenientes de digestores tubulares rurales alimentados con estiércol bovino, estiércol porcino y co-digestión estiércol bovino-lactosuero Proyecto 2504). Ivet Ferrer and Marianna Garfí are grateful to the Government of Catalonia (Consolidated Research Group 2017 SGR 1029). Marianna Garfí is grateful to the Spanish Ministry of Economy and Competitiveness (RYC-2016-20059). Peer Reviewed Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant Objectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables

Supervisors' opportunity to observe incumbents' performance (i.e., how often a supervisor typically sees an employee's performance) has been suggested to be important for accurate performance rating and to be a moderator of criterion‐related validity. Here we test these suggestions and present empirical evidence for the effects of opportunity to observe. In Study 1, supervisors in a multi‐occupation/organization criterion‐related validation study for a biodata measure indicated the opportunity they had to observe incumbents. The data were split according to different levels of opportunity to observe. Higher validities were found when opportunity to observe was maximal. In Study 2, this finding was replicated using a cognitive ability test. These results suggest that psychologists should consider measuring opportunity to observe in criterion‐related validity studies.

The aim of this paper was to deepen the knowledge of anaerobic co-digestion of lignocellulosic residues and evaluate the role of soluble organic matter during co-digestion. Buckwheat milling residue (buckwheat hull) was co-digested with different organic wastes to evaluate the effect of co-digestion on biomethane yield, process stability, and their relationship with soluble organic matter. Results showed that co-digestion increased the biomethane yields of buckwheat hull and the best result was achieved from the co-digestion with slaughterhouse wastes (+254% of cumulative biomethane production). Kinetic analysis showed that fruit wastes and brewery trub affected positively anaerobic digestion of lignocellulosic residues, enhancing biomethane potential (+84% and +166%, respectively) and reducing lag phase duration. A positive correlation was found between the soluble organic matter and the biomethane yields during co-digestion experiments. Nevertheless, co-digestion with fruit wastes was affected by an excessive acidification in the early stage of AD (pH 5.7) caused by the rapid conversion of sugars into volatile fatty acids (7 g L-1 at day 15). Although all the digestates showed high concentrations of plant nutrients (the average content of total N was 7.8% dry weight), they were also characterized by residual phytotoxicity (germination index was always 0.0%). results. Increasing the amount of easy biodegradable organic matter during lignocellulosic residues treatment should be the main goal when selecting co-digestion substrates. Chemical composition of co-digestion substrates should be carefully considered, with particular regard to soluble organic matter, to ensure the optimal development of anaerobic digestion with lignocellulosic residues.

When used in conjunction with employee surveys, focus groups can provide valuable qualitative data to support the employee survey process. Focus groups held prior to survey development and administration can uncover issues worthy of investigation and evaluate draft survey questions for sensitivity and readability. Post-survey focus groups can elucidate issues identified by the survey, solicit organizational members’ suggestions for resolving these issues, and gain management and employee feedback on possible programs to address identified issues. After describing how focus groups fit into the context of industrial–organizational psychology methodology, the authors outline steps for designing and conducting focus group studies and for analyzing the resulting data and reporting findings. The chapter concludes with an annotated list of additional resources for conducting focus groups.

Purpose The purpose of this paper is to examine the presence of generational differences in items measuring workplace attitudes (e.g. job satisfaction, employee engagement). Design/methodology/approach Data from two empirical studies were used; the first study examined generational differences in large sample, multi-organizational administrations of an employee survey at both the item and general-factor levels. The second study compared job satisfaction ratings between parents and their children from a large nationwide longitudinal survey. Findings Although statistically significant, most generational differences in Study 1 did not meet established cutoffs for a medium effect size. Type II error was ruled out given the large power. In Study 2, generational differences again failed to reach Cohen’s cutoff for a medium effect size. Across both studies, over 98 percent of the variance in workplace attitudes lies within groups, as opposed to between groups, and the distributions of scores on these variables overlap by over 79 percent. Originality/value Prior studies examining generational differences in workplace attitudes focused on scale-level constructs. The present paper focused on more specific item-level constructs and employed larger sample sizes, which reduced the effects of sampling error. In terms of workplace attitudes, it appears that generations are more similar than they are different.

We investigated the effects of empirical keying on scoring personality measures. To our knowledge, this is the first published study to investigate the use of empirical keying for personality in a selection context. We hypothesized that empirical keying maximizes use of the information provided in responses to personality items. We also hypothesized that it reduces faking since the relationship between response options and performance is not obvious to respondents. Four studies were used to test the hypotheses. In Study 1, the criterion-related validity of empirically keyed personality measures was investigated using applicant data from a law enforcement officer predictive validation study. A combination of training and job performance measures was used as criteria. In Study 2, two empirical keys were created for long and short measures of the five factors. The criterion-related validities of the empirical keys were investigated using Freshman GPA (FGPA) as a criterion. In Study 3, one set of the empirical keys from Study 2 was applied to experimental data to examine the effects of empirical keying on applicant faking and on the relationship of personality scores and cognitive ability. In Study 4, we examined the generalizability of empirical keying across different organizations. Across the studies, option- and item-level empirical keying increased criterion-related validities for academic, training, and job performance. Empirical keying also reduced the effects of faking. Thus, both hypotheses were supported. We recommend that psychologists using personality measures to predict performance should consider the use of empirical keying as it enhanced validity and reduced faking.

Bioplastics are becoming more and more widespread as substitutes for petroleum-derived plastics due to their biodegradability. Bioplastics degradation under different environments has been described and reported to depend mainly on bioplastics' compositions and the environmental conditions. Incomplete degradation during waste management processes and leakage of bioplastics into the environment are becoming major concerns that need to be further investigated. In this context, the present paper aimed to review recent literature dealing with biodegradation of bioplastics under industrial (e.g. anaerobic digestion and composting) and natural (e.g. soil and water) environments, and to link it to the potential bioplastics' leakage into the environment. Reviewed data were used to estimate the potential role of waste management processes in decreasing the potential leakage of bioplastics. Depending on bioplastics' type and processing conditions, waste management can effectively reduce bioplastics' potential leakage, decreasing the concentration of these materials that can reach the natural environments.

One of the typical roles of industrial–organizational (I-O) psychologists working as practitioners is administering employee surveys measuring job satisfaction/engagement. Traditionally, this work has involved developing (or choosing) the items for the survey, administering the items to employees, analyzing the data, and providing stakeholders with summary results (e.g., percentages of positive responses, item means). In recent years, I-O psychologists moved into uncharted territory via the use of survey key driver analysis (SKDA), which aims to identify the most critical items in a survey for action planning purposes. Typically, this analysis involves correlating (or regressing) a self-report criterion item (e.g., “considering everything, how satisfied are you with your job”) with (or on) each of the remaining survey items in an attempt to identify which items are “driving” job satisfaction/engagement. It is also possible to use an index score (i.e., a scale score formed from several items) as the criterion instead of a single item. That the criterion measure (regardless of being a single item or an index) is internal to the survey from which predictors are drawn distinguishes this practice from linkage research. This methodology is not widely covered in survey methodology coursework, and there are few peer-reviewed articles on it. Yet, a number of practitioners are marketing this service to their clients. In this focal article, a group of practitioners with extensive applied survey research experience uncovers several methodological issues with SKDA. Data from a large multiorganizational survey are used to back up claims about these issues. One issue is that SKDA ignores the psychometric reality that item standard deviations impact which items are chosen as drivers. Another issue is that the analysis ignores the factor structure of survey item responses. Furthermore, conducting this analysis each time a survey is administered conflicts with the lack of situational and temporal specificity. Additionally, it is problematic to imply causal relationships from the correlational data seen in most surveys. Most surprisingly, randomly choosing items out of a hat yields validities similar to those from conducting the analysis. Thus, we recommend that survey providers stop conducting SKDA until they can produce science that backs up this practice. These issues, in concert with the lack of literature examining the practice, make rigorous evaluations of SKDA a timely inquiry.

Abstract. Varimax rotated principal component scores (VRPCS) have previously been offered as a possible solution to the non-orthogonality of scores for the Big Five factors. However, few researchers have examined the reliability and validity of VRPCS. To address this gap, we use a lab study and a field study to investigate whether using VRPCS increase orthogonality, reliability, and criterion-related validity. Compared to the traditional unit-weighting scoring method, the use of VRPCS enhanced the reliability and discriminant validity of the Big Five factors, although there was little improvement in criterion-related validity. Results are discussed in terms of the benefit of using VRPCS instead of traditional unit-weighted sum scores.

Summary In recent years, there has been an increasing emphasis on the role of theory in organizational behavior (OB) research. Authors are strongly encouraged to develop “theory” in their manuscripts and to make “theoretical contributions.” This trend is in stark contrast to the process used in other fields of science. Our counterparts in those fields follow the scientific method and define theory as a concise and elegant hypothesis that has survived extensive empirical testing. Rather than being based on extensive empirical research, many of OB's theories are based on a limited number of primary studies (at best) or speculation and conjecture (at worst). OB researchers are discouraged from testing other researchers' theories or replicating previously published work. Consequently, many OB theories do not meet the criteria for a true scientific theory. We propose that OB researchers should re-embrace the scientific method and focus on creating a body of empirical research that could be used in the future to establish true scientific theories (through extensive hypothesis testing, empirical research, and conceptual replications) rather than concocting pseudotheories. Research in the personnel selection subfield of OB provides a reasonable exemplar of this model, yet it has been derided of late for being too atheoretical. Copyright © 2016 John Wiley & Sons, Ltd.

It is well-known that some students earn higher grades than others; however, published research on the mental abilities that are correlated with high school grades is sparse. Two studies examined the relationship between different mental abilities and high school grades. Study 1 showed that the personality trait conscientiousness predicted high school grades (r = .32) almost as well as g (r = .37 to .40). In Study 2, the relationship between general mental ability (g) and high school grades was linear and fairness analyses indicated slight overprediction for Hispanics and Blacks and underprediction for females. Validity was lowered slightly by group preferences. With the exception of mathematical knowledge, the correlation between mental abilities and high school grades in both studies was largely attributable to g rather than specific abilities (s) measured by each test. Additional analyses showed that grade point averages are reliable and conscientiousness and g do not interact when predicting high school grades.

The positive relationship between complexity of work and the validity of general mental ability (GMA) measures across a variety of occupations is well supported by research and provides important practical and theoretical support for cognitive ability measures. However, there is currently no research demonstrating a systematic relationship between the size of the validities of any personality measure and the personality requirements of jobs, thus leaving open to question the predictive and construct validity of personality measures for applicant selection. We compared the validities of two biodata measures – one scored to measure social competence and one to measure GMA – across six job families that varied in social requirements. The validity of the GMA measure generalized at approximately the same level across the job families while the validity of the social competence measure decreased as social requirements diminished.

A conceptual rationale is presented for the use of a high-fidelity simulation: a video-based test (VBT), in which applicants view job-related scenarios, respond orally, and are later scored on five dimensions by trained raters. Using applicant data, we empirically investigate the criterion-related validity, reliability, and utility of the VBT. Overall, we found that the VBT predicted performance in training and on the job. In addition, different raters strongly agreed with one another on each applicant's scores. Despite somewhat higher development costs, the VBT demonstrated high utility. We suggest that organizations consider the use of VBTs as a selection instrument for jobs that require the use of applied social and interpersonal skills.

It is often said that the federal government needs to be more like the private sector (Brooks, 2013; Campbell, 2011; Harvey, 2012; Miller, 2013; Neal, 2013; Schnurer, 2013). However, after reading Jones and Stout's (2015) summary of private-sector antinepotism policies, we wonder whether the opposite is true when it comes to nepotism and cronyism: Should the private sector be more like the federal government? According to Jones and Stout, many organizations have antinepotism policies that prohibit the employment of the friends and family of current employees. We believe that these policies might go too far, and we propose that the policies used by the federal government could serve as a model for private-sector organizations. We also think that the federal government can shed some light on why organizations want to prohibit nepotism and cronyism.

Past research has shown that mental ability tests predict training and job performance by virtue of measuring general mental ability (g). After removing the effects of g, mental ability tests no longer predict performance, with the exception of perceptual speed and spatial abilities for certain occupations. In our study, we found evidence for a third exception: Meaningful Memory, the ability to learn and recall information that has meaningfully-related content predicts training performance (ρ = .511), even after removing the effects of g. Therefore, Meaningful Memory tests show promise in enhancing the effectiveness of mental ability tests to predict training performance.

The factor structure of mental abilities has most often been depicted using a higher-order model. Under this model, general mental ability (g) is placed at the top of a pyramid, with “loading” arrows going from it to the other factors of intelligence, which in turn go to subtest scores. In contrast, under the bifactor model (also known as the nested factors/direct hierarchical model), each subtest score has its own direct loading on g; the non-g factors (e.g., the broad abilities) do not mediate the relationships of the subtest scores with g. Here we summarized past research that compared the fit of higher-order and bifactor models using confirmatory factor analysis (CFA). We also analyzed additional archival datasets to compare the fit of the two models. Using a total database consisting of 31 test batteries, 58 datasets, and 1,712,509 test takers, we found stronger support for a bifactor model of g than for the traditional higher-order model. Across 166 comparisons, the bifactor model had median increases of 0.076 for the Comparative Fit Index (CFI), 0.083 for the Tucker-Lewis Index (TLI), and 0.078 for the Normed Fit Index (NFI) and decreases of 0.028 for the root mean square error of approximation (RMSEA) and 1343 for the Akaike Information Criterion (AIC). Consequently, researchers should consider using bifactor models when conducting CFAs. The bifactor model also makes the unique contributions of g and the broad abilities to subtest scores more salient to test users.

Five quasi-rational biodata scales were developed by empirically keying biodata items to predict scores on a measure of the Big Five dimensions of personality. The criterion-related validities of the quasi-rational scales were compared to empirical and rational biodata keying methods using supervisory ratings of job performance as the criterion. Empirical keying outperformed the quasi-rational and rational methods (which had similar validities).

Recently emerging evidence suggests that the dominant structural model of mental abilities-the Cattell-Horn-Carroll (CHC) model-may not adequately account for observed scores for mental abilities batteries, leading scholars to call into question the model's validity. Establishing the robustness of these findings is important since CHC is the foundation for several contemporary mental abilities test batteries, such as the Woodcock-Johnson III (WJ-III). Using confirmatory factor analysis, we investigated CHC's robustness across 4 archival samples of mental abilities test battery data, including the WJ-III, the Kaufman Adolescent & Adult Intelligence Test (KAIT), the Kaufman Assessment Battery for Children (KABC), and the Differential Ability Scales (DAS). We computed omega hierarchical (ωH) and omega subscale (ωS) coefficients for g and the broad factors, which estimated the relationship of composite scores to g and the broad factors, respectively. Across all 4 samples, we found strong evidence for a general ability, g. We additionally found evidence for 3 to 9 residualized, orthogonal broad abilities existing independently of g, many of which also explained reliable variance in test battery scores that cannot be accounted for by g alone. The reliabilities of these broad factors, however, were less than desirable (i.e.

The criterion-related validities of empirical, rational, and hybrid keying procedures for a biodata inventory were compared at different sample sizes. Rational keying yielded the lowest validities. Hybrid keying performed best at the smallest sample sizes studied, followed by empirical keying at moderate sizes, and stepwise regression weighting of items at the largest sample sizes.

This study investigated linear and curvilinear relationships between performance at a US law enforcement training academy and both facet and factor personality scales linking to conscientiousness (i.e. dependability and achievement) and emotional stability (i.e. stress resistance and frustration tolerance). For both conscientiousness and emotional stability, the use of separate facet scales provided the best prediction of training grades when linear and quadratic effects were considered. In all cases, the curvilinear relationships indicated that differences in scores at the low end of the distribution were more predictive of training grades than were differences in scores at the high end of the distribution. Results are discussed in terms of the value of using facet scales to predict performance and the importance of considering curvilinear relationships between personality and specific criteria, such as training grades.

This study examined the effects of item format (single-stimulus vs. forced-choice) and response motivation (honest vs. applicant) on scores for personality scales measuring Conscientiousness and Openness to Experience. Consistent with the hypotheses, cognitive ability was related to forced-choice personality scores in the applicant condition but not in the honest condition. Cognitive ability was unrelated to single-stimulus personality scores in both the applicant and honest conditions. The results suggest that controlling for cognitive ability can reduce the incremental predictive validity of forced-choice personality scales in applicant settings. Findings are discussed in terms of the importance of considering how item format influences the construct and criterion-related validity of personality tests used to make selection decisions.

This study tested the hypothesis that personality-based job analysis (PBJA) ratings are correlated with subject matter expert (SME) personality scale scores (through a self-serving bias). Some support was found for the hypothesis. However, PBJA ratings were somewhat predictive of the criterion-related validity of scale scores for the big five personality dimensions.

This study investigated whether scores of item response accuracy (AC) and item response latencies (RLs) from a computer based artificial language test (ALT) uniquely predicted grades in a Spanish language course at a U.S. law enforcement training academy. As expected, ALT–RLs added to the prediction of course grades provided by ALT–AC. This finding held even after controlling for scores on a logical reasoning test. Results are discussed in terms of the potential benefits of using RLs to predict performance in training.

This article evaluated the validity of two traditional traitedness measures (i.e., standard deviation traitedness measures and global, single-item traitedness measures) and three new traitedness measures (i.e., multi-item, ranking, and facet traitedness measures). Overall, there was poor construct validity for both the traditional and new measures of traitedness. Furthermore, traitedness was a spurious moderator of the relationship between openness to experience and academic performance. Finally, evidence of nonlinear personality-academic performance relationships was discovered.

The purpose of this study was to investigate whether worker-oriented job analysis importance ratings were influenced by subject matter experts' (SME) standing (as measured by self-rated performance) on a competency. This type of relationship (whereby SMEs indicate that the traits they have are important for successful job performance) is an example of the self-serving bias (which is widely described in the social cognition literature and rarely described in the industrial/organizational psychology literature). An archival dataset covering 57 clerical and technical occupations with 26,682 participants was used. Support was found for the relationship between self-rated performance and importance ratings. Significant relationships (typically in the .30s) were observed for all 31 competencies that were studied. Controls were taken to account for common method bias and differences in the competencies required for each of the 57 occupations. Past research has demonstrated the effects of the self-serving bias on personality-based job analysis ratings. This study was the first to extend these findings to traditional job analysis, which covers other competencies in addition to personality. In addition, this study is the first to use operational field data instead of laboratory data.

This article presents the results of 2 studies that examine the effect of presenting a warning of response verification by others on the relationship between measures of personality and cognitive ability. In both a field study and a laboratory study, stronger correlations were generally found between measures of personality and cognitive ability when a warning of verification was present. The results from the studies also showed that the warning of verification was associated with slower item response latencies for certain personality scales, suggesting that exposure to the warning increased the complexity of the response decision. Results are discussed in terms of the effects of altering test instructions on the construct validity of personality measures used in applied settings.

Recent behavioral experiments on auditory masking and waveform discriminations using harmonic complexes as stimuli have shown significant differences in performance between birds and humans. In humans, but not in birds, Schroeder‐phase harmonic complexes constructed with monotonically increasing (positive Schroeder) or decreasing (negative Schroeder) component phases are differentially effective as maskers, even though they have identical temporal envelopes and long‐term spectra. The similarity in masking effectiveness of these harmonic complexes notwithstanding, birds can easily discriminate the fine‐structure differences between the positive and negative Schroeder waveforms even with harmonic periods as short as 2 ms. By contrast, humans are unable to make these discriminations unless the periods are greater than about 5–6 ms. These behavioral discrimination and masking results have now been replicated by measuring evoked‐potential responses in budgerigars. Amplitude and waveform shapes of the compound action potentials reflect the behavioral discriminations between the two Schroeder stimuli, but cochlear microphonics do not. The similarity in results between the behavioral and the electrophysiological studies, using the same stimuli, suggest differences in both temporal and spectral processing in avian versus mammalian cochleas. [Work supported by NIH R01 DC00198, DC00626, and NRSA DC00046.]