Browsing by Subject "accuracy"
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- ItemOpen AccessAnalysis of tender sum forecasting by quantity surveyors and contractors in South Africa(2003) Pearl, R G; Akintoye, A; Bowen, P A; Hardcastle, CAlthough extensive research has been undertaken on the accuracy of quantity surveyors' tender price forecasts, very little of this research contains information relating to the factors affecting tender sum forecasting by quantity surveyors and contractors. The primary objective of this empirical study was to gain insight into the factors influencing both quantity surveyors' and contractors' tender price forecasts. This was achieved through an analysis of tender information relating to 278 projects for a fifteen-year period and collected from 30 quantity-surveying practices and MBATA tender records. The analysis of South African tender information reported in this article indicates an average forecast performance by quantity surveyors of 8.33% (std dev (standard deviation) = 11,183, CV (coefficient of variation) = 134,2%). The variability of contractors' tenders ranged from 0,37% to 46,53%, with a mean of 5,65% (std dev = 5,22, SE (standard error) = 0,313). Furthermore, there is no evidence to suggest that forecast performance is dependent on type of project, client, function of project, size of project, location of project and number of bidders. The contractor's results suggest that local authority projects are associated with high variability of their tender sum forecasts. The only factor, which shows significance for quantity surveyors, is the date of tender which may tend to point to the importance of market conditions and economic cycle in the tender sum forecast performance of South African quantity surveyors.
- ItemOpen AccessAnalysis of tender sum forecasting by quantity surveyors and contractors in South Africa(2003) Pearl, R G; Akintoye, A; Bowen, P A; Hardcastle, CAlthough extensive research has been undertaken on the accuracy of quantity surveyors' tender price forecasts, very little of this research contains information relating to the factors affecting tender sum forecasting by quantity surveyors and contractors. The primary objective of this empirical study was to gain insight into the factors influencing both quantity surveyors' and contractors' tender price forecasts. This was achieved through an analysis of tender information relating to 278 projects for a fifteen-year period and collected from 30 quantity-surveying practices and MBATA tender records. The analysis of South African tender information reported in this article indicates an average forecast performance by quantity surveyors of 8.33% (std dev (standard deviation) = 11,183, CV (coefficient of variation) = 134,2%). The variability of contractors' tenders ranged from 0,37% to 46,53%, with a mean of 5,65% (std dev = 5,22, SE (standard error) = 0,313). Furthermore, there is no evidence to suggest that forecast performance is dependent on type of project, client, function of project, size of project, location of project and number of bidders. The contractor's results suggest that local authority projects are associated with high variability of their tender sum forecasts. The only factor, which shows significance for quantity surveyors, is the date of tender which may tend to point to the importance of market conditions and economic cycle in the tender sum forecast performance of South African quantity surveyors.
- ItemOpen AccessConsidering Broad vs. Narrow Personality Traits of Raters as Predictors of Rating Accuracy in Social Media Judgements of Personality(2022) Visser, Selene; de Kock, FrancoisPrevious research has shown that the personality characteristics of raters seem to play a minor role in shaping the accuracy of their personality judgments of other people. However, as prior research studies relied largely on broad (i.e., dimension-level) trait measures to operationalise rater personality, it is unclear if raters' narrow (i.e., facet-level) trait measures may predict their rating accuracy. There are reasons to believe that narrow traits may relate more strongly to accuracy compared to broad traits, due to enhanced conceptual correspondence and improved fidelity (rather than bandwidth) relative to accuracy criteria. The aim of the present study was to determine whether narrow traits of raters predict accuracy, and if so, whether these narrow traits increment prediction of accuracy beyond broad traits. To this end, a secondary research design was used. Primary data from a previous study of 456 students' personality judgments of five target social media profiles were reanalysed. Personality traits of judges were operationalised at both broad vs. narrow traits and accuracy criteria were regressed against these predictors. In line with prior research on broad personality traits, the findings revealed that specific narrow traits were not generally predictive of personality rating accuracy from Facebook social media information. However, compared to broad traits, narrow traits were marginally better predictors of accuracy. Overall, results support the growing consensus that rater personality traits are not important to produce accurate ratings of personality, irrespective of the level at which we measure them (broad vs. narrow traits). The study adds to the growing momentum of research indicating raters can be accurate regardless of their personality traits. Therefore, organisations that wish to enhance their rating screening and training programmes might find more value in focusing on rater cognitive factors, rather than on their personality traits.
- ItemOpen AccessDo Rater Personality Traits Moderate the Relationship Between Intelligence and Rating Accuracy in Interviews?(2021) Bassier, Laeeqa; de Kock, FrancoisResearch on judgment accuracy in human resource management shows that various rater characteristics predict accuracy, but emerging findings suggest that these individual differences may interact with one another (rather than being direct effects). The present study aimed to add to this area of research by determining how rater personality traits may moderate the relationship between GMA and rating accuracy. Secondary data collected in a prior study of police managers undergoing a seven-week managerial training course in South Africa (N =146) were analysed. The findings supported that selected rater personality traits may moderate the relationship between intelligence and rating accuracy. For example, rater intelligence was a better predictor of accuracy when the judge was more agreeable. Intellectance and conscientiousness were found to have no significant moderating effect on the relationship between intelligence and rating accuracy. Only three out of the Big Five Personality traits were examined in this research study. Importantly, the study contributed to theory by expanding the Good Judge model (De Kock et al., 2020), analysing how individual differences in the ability and trait domains may potentially interact to influence accuracy. In addition to enhancing our understanding of how rater personality constructs may affect accuracy, the study discusses important implications for practices, such as rater training and selection.
- ItemOpen AccessTell me about your (Facebook) self: recruiter personality traits and accuracy of personality judgement of candidate Facebook profiles(2018) Rauch, Philippa; de Kock, FrancoisThe use of social networking sites, such as Facebook, in the job application screening process has changed the recruitment landscape. Many human resource (HR) professionals and recruiters have begun to use social networking sites as a tool to attract, source and screen potential candidates. When screening candidates’ Facebook profiles, recruiters make personality judgements that have important consequences for hiring decisions. However, little is known about what makes a good judge of personality in the world of online screening for recruitment. This study investigated the relationship between recruiters’ Big Five personality traits (extraversion, agreeableness, conscientiousness, openness to experience and neuroticism) and their ability to judge accurately candidates’ personality traits from their Facebook profiles. In particular, distinctive accuracy measures were employed which account for personality profile normativeness, or the degree to which applicants being rated are generally alike – an important limitation of earlier profile accuracy measures. Results from 456 university students who judged five actual Facebook profiles for which ‘true score’ estimates on personality traits were possible, revealed that recruiters were generally able to infer applicants’ personality traits from their Facebook profiles. However, recruiter personality was not an important factor in their judgement accuracy, neither when accuracy was operationalised as traditional profile accuracy measures, nor as distinctive accuracy.
- ItemOpen AccessThe impact of the gas distribution on the determination of dynamical masses of galaxies using unresolved observations(2014) de Blok, W J G; Walter, FabianDynamical mass (M dyn) is a key property of any galaxy, yet a determination of M dyn is not straightforward if spatially resolved measurements are not available. This situation occurs in single-dish H I observations of the local universe, but also frequently in high-redshift observations. M dyn measurements in high-redshift galaxies are commonly obtained through observations of the CO line, the most abundant tracer of the molecular medium. Even though in most cases the CO line width can be determined with reasonable accuracy, a measurement of the size of the emitting region is typically challenging given current facilities. We show how the integrated spectra ("global profiles") of a variety of galaxy models depend on the spatial distribution of the tracer gas as well as its velocity dispersion. We demonstrate that the choice of tracer emission line (e.g., H I tracing extended, "flat," emission versus CO tracing more compact, "exponential," emission) significantly affects the shape of the global profiles. In particular, in the case of high (~50 km s–1) velocity dispersions, compact tracers (such as CO) result in Gaussian-like (non-double-horned) profiles, as is indeed frequently seen in high-redshift observations. This leads to significantly different determinations of M dyn if different distributions of the tracer material ("flat" versus "exponential") are considered. We determine at which radii the rotation curve reaches the rotation velocity corresponding to the velocity width, and find that for each tracer this happens at a well-defined radius: H I velocity widths typically originate at ~5 optical scale lengths, while CO velocity widths trace the rotation velocity at ~2 scale lengths. We additionally explore other distributions to take into account that CO distributions at high redshift likely differ from those at low redshift. Our models, while not trying to reproduce individual galaxies, define characteristic radii that can be used in conjunction with the measured velocity widths in order to define dynamical masses consistent with the assumed gas distribution.
- ItemOpen AccessWhen more is not better: understanding the potential nonlinear relationship between intelligence and rating accuracy(2022) Schade, Marizanne; de Kock, FrancoisEmployers rely on judges or raters to accurately rate the potential or performance of candidates through interviews or assessment centre evaluations. As the judgment process places heavy demands on information processing, cognitive ability (of raters) is important to detect and interpret behavioural cues presented by those being rated. A consistent empirical finding is that intelligence is the strongest predictor of rating accuracy, but prior research has largely been based on linear models. However, researchers have yet to investigate whether these variables could be nonlinearly related. By studying nonlinear models in judgment and accuracy, we can not only deepen our understanding of the ‘good judge' in HRM, but we may further enhance methods to select and train raters in applied practice. This secondary research study re-analysed data from a prior published study to evaluate the relationship between rater intelligence and accuracy of interview ratings provided by 146 South African managers. The predictiveness of an ordinary least squares (OLS) linear regression model was compared to two nonlinear models (quadratic and cubic) to determine which statistical approach explained the most variance in rating accuracy scores. Findings provided further support of a linear relationship between intelligence and rating accuracy suggesting no quadratic or cubic interactions. Judges, therefore, produced more accurate ratings at higher levels of intelligence. Possible explanations of the findings include the sample size and task complexity. Study limitations and recommendations for future research are discussed in detail