Greater Number Of Categories Research Articles

Comparing IRT properties among different category numbers: a case from attitudinal measurement on physics education research

Collapsing different category numbers within attitudinal measurement on learning and instruction can be an option of physics education research (PER) scholars while interpreting categorical responses from participants. Psychometric evaluation of the different category numbers, however, has inconclusive results to date. Item response theory (IRT) offers psychometric framework at the item level that has been approached in this study to explore psychometric properties of five different number of categories. One thousand artificial data within five number of categories were generated based on the underlying marginal distribution and the inter item correlation matrix. Statistical parameters [item estimates and test information functions (TIFs)] from Graded Response Model (GRM) were employed to describe the psychometric behaviors of the studied category numbers. Our findings demonstrated that the discrimination index among the five category numbers remained constant. Global fit indices had no distinguishable information to differentiate the varying category numbers. Based on the item location and TIF, our results confirmed previous works that more information will be raised by the greater number of categories. The implication intended by this study should offer a key recommendation for a case from attitudinal measurement on the PER community or even beyond the psychometric field.

Should Estimated Glomerular Filtration Rate Be Adjusted for Race?

Should Estimated Glomerular Filtration Rate Be Adjusted for Race?

An Investigation of Coding Schemes for Sample Entropy Analysis of Communications Data

An investigation into the effect of coding scheme choice for sample entropy analysis of communications data is presented. Semantic content and speaker encoding of transmissions are explored. The results suggest a scheme with a greater number of categories will more likely pass surrogate testing, whether through finer distinctions of semantic categorization or through the additions of a speaker-content interaction. The results also suggest the way semantic categories are formed affects how well the scheme permits discrimination between workload conditions with a known effect.

Large Scale Analysis of Relative Age Effect on Professional Soccer Players in FIFA Designated Zones

The aim of this study was to analyse the occurrence and the magnitude of the Relative Age Effects (RAEs) in professional soccer players, and whether this effect is different depending on their position, the leagues where they play, the level of the competition, the level of the team in which they play and their nationality. The sample was composed by 12,144 professional players who participated in the professional leagues during the 2014-2015 season. The date of birth of each player was classified into four birth quartile (Q1, Q2, Q3 and Q4). Most professional soccer players are in the nearest quartiles at the beginning of the selection year, resulting in a decrease in birth as far as furthest quartiles are concerned. The RAE was found in the first (Effect Size= small) and second division (ES=medium) of competitions and in all the leagues analysed, except in the Premier League (England) and the K-League Classic (South Korea). Moreover, all playing positions (goalkeeper, defender, midfielder and forward) in soccer was affected by RAEs. In order to reduce RAE several solutions have been proposed by scientific literature that may be adopted by coaches and soccer clubs (i.e. greater number of categories, rotate court dates, or establish technical-coordinative reference values per quartile of birth).

Predictive ability of models for calving difficulty in US Holsteins

The performance of alternative threshold models for analyzing calving difficulty (CD) in Holstein cows was evaluated in terms of predictive ability. Four models were considered, with CD classified into either three or four categories and analysed either as a single trait or jointly with gestation length (GL). The data contained GL and CD records from 90 393 primiparous cows, sired by 1122 bulls and distributed over 935 herd-calving year classes. Predictive ability of each model was evaluated using four criteria: mean squared error of the difference between observed and predicted CD scores; a Kullback-Leibler divergence measure between the observed and predicted distributions of CD scores; Pearson's correlation between observed and predicted CD scores and ability to correctly classify bulls as above or below average for incidence of CD. In general, the four models had similar predictive abilities. The joint analysis of CD with GL produced little, if any, improvement in predictive ability over univariate models. In light of the small difference in predictive ability between models treating CD with three or four categories and considering that a greater number of categories can provide more information, analysis of CD classified into four categories seems warranted.

Pictorial superiority effects in oldest-old people

We examined memory for pictures and words in middle-age (45–59 years), young-old (60–74 years), old-old (75–89 years), and the oldest-old adults (90–97 years) in the Louisiana Healthy Aging Study. Stimulus items were presented and retention was tested in a blocked order where half of the participants studied 16 simple line drawings and the other half studied matching words during acquisition. Free recall and recognition followed. In the next acquisition/test block a new set of items was used where the stimulus format was changed relative to the first block. Results yielded pictorial superiority effects in both retention measures for all age groups. Follow-up analyses of clustering in free recall revealed that a greater number of categories were accessed (which reflects participants’ retrieval plan) and more items were recalled per category (which reflects participants’ encoding strategy) when pictures served as stimuli compared to words. Cognitive status and working memory span were correlated with picture and word recall. Regression analyses confirmed that these individual difference variables accounted for significant age-related variance in recall. These data strongly suggest that the oldest-old can utilise nonverbal memory codes to support long-term retention as effectively as do younger adults.

Effect of the number of scale points on chi‐square fit indices in confirmatory factor analysis

This article investigates the effect of the number of item response categories on chi‐square statistics for confirmatory factor analysis to assess whether a greater number of categories increases the likelihood of identifying spurious factors, as previous research had concluded. Four types of continuous single‐factor data were simulated for a 20‐item test: (a) uniform for all items, (b) symmetric unimodal for all items, (c) negatively skewed for all items, or (d) negatively skewed for 10 items and positively skewed for 10 items. For each of the 4 types of distributions, item responses were divided to yield item scores with 2,4, or 6 categories. The results indicated that the chi‐square statistic for evaluating a single‐factor model was most inflated (suggesting spurious factors) for 2‐category responses and became less inflated as the number of categories increased. However, the Satorra‐Bentler scaled chi‐square tended not to be inflated even for 2‐category responses, except if the continuous item data had both negatively and positively skewed distributions.