Difficult Items Research Articles

Evaluation of three patient reported outcome measures following operative fixation of closed ankle fractures

BackgroundSeveral patient reported outcome measures (PROMs) are available for assessing the outcomes of ankle fracture but few have been compared for recommended measurement properties. This study compares the measurement properties of the Lower Extremity Function Scale (LEFS), Olerud Molander Ankle Score (OMAS) and Self-Reported Foot and Ankle Score (SEFAS) following ankle surgery.MethodsThe retrospective cohort study included 959 patients aged 18 years and over who underwent surgical treatment (ORIF) for unstable and closed ankle fractures in SE Norway. The PROMs were included in a postal questionnaire sent to patients’ homes in 2015, three years after surgery. Missing data, structural validity, internal consistency, test-retest reliability and validity were assessed.ResultsConfirmatory factor analysis results showed model fit for the SEFAS and a bi-dimensional LEFS with scales of easy and difficult items. The OMAS performed less satisfactorily. Cronbach’s alpha and test-retest correlations ranged from 0.82 to 0.96 and 0.91 to 0.93 respectively. The smallest detectable differences for group and individual comparisons were 14.1 to 20.6 and 0.93 to 1.55; SEFAS performed best. As hypothesised, instrument scores were highly correlated and with those for the EQ-5D and SF-36 physical functioning. Mean imputation where half or more items are completed increased usable scores by 1.4–15.7% without affecting measurement properties.ConclusionsThe three instruments largely performed satisfactorily in relation to important measurement properties but the LEFS had evidence for two dimensions relating to easier and more difficult aspects of function. Mean imputation where half or more items are completed increased the number of usable responses for all three instruments. The three instruments represent different approaches to measuring outcomes and their content should be considered carefully when choosing between them. The SEFAS is designed for a range of foot disorders including ankle fractures and has the best measurement properties in this population.

Examining Teachers’ Knowledge of Line Graph Task: a Case of Travel Task

Teachers should possess a robust knowledge of graph interpretation in a world that requires increasingly scientific citizens. This study aimed to investigate teachers’ knowledge of interpreting a context-based line graph, by understanding the types of difficulties teachers have in interpreting such graphs. The study also sought to determine whether there were gender differences in teachers’ graph interpretation skills and determine whether these interpretation skills were different among teachers with varying teaching experiences. Sixty-one teachers from ten districts in one Indonesian province participated in this study. Empirically derived items were developed to identify the teacher’s conceptual understanding of line graphs with Curcio’s (Journal for Research in Mathematics Education, 18(5), 382–393, 1987) level of interpretation applied to explain the difficulties encountered. This study revealed that most of the teachers had difficulty answering questions that required ‘reading beyond the data’. Specifically, these teachers interpreted the graph as an iconic representation of a real event rather than an abstract representation of data (i.e., speed vs. time). Performance differences in teachers’ understanding of the graph were dependent on the grade level they taught, with differences especially evident in the interpretation of moderate and difficult items. There were no differences in teachers’ understanding by gender or years of teaching experience. The results highlight the importance of focusing on teacher professional development centering on teachers’ knowledge of graph comprehension.

Item Analysis of Multiple Choice Questions at the Department of Paediatrics, Arabian Gulf University, Manama, Bahrain.

The current study aimed to carry out a post-validation item analysis of multiple choice questions (MCQs) in medical examinations in order to evaluate correlations between item difficulty, item discrimination and distraction effectiveness so as to determine whether questions should be included, modified or discarded. In addition, the optimal number of options per MCQ was analysed. This cross-sectional study was performed in the Department of Paediatrics, Arabian Gulf University, Manama, Bahrain. A total of 800 MCQs and 4,000 distractors were analysed between November 2013 and June 2016. The mean difficulty index ranged from 36.70-73.14%. The mean discrimination index ranged from 0.20-0.34. The mean distractor efficiency ranged from 66.50-90.00%. Of the items, 48.4%, 35.3%, 11.4%, 3.9% and 1.1% had zero, one, two, three and four nonfunctional distractors (NFDs), respectively. Using three or four rather than five options in each MCQ resulted in 95% or 83.6% of items having zero NFDs, respectively. The distractor efficiency was 91.87%, 85.83% and 64.13% for difficult, acceptable and easy items, respectively (P <0.005). Distractor efficiency was 83.33%, 83.24% and 77.56% for items with excellent, acceptable and poor discrimination, respectively (P <0.005). The average Kuder-Richardson formula 20 reliability coefficient was 0.76. A considerable number of the MCQ items were within acceptable ranges. However, some items needed to be discarded or revised. Using three or four rather than five options in MCQs is recommended to reduce the number of NFDs and improve the overall quality of the examination.

The efficacy of learners' testing choices.

Practice tests provide large mnemonic benefits over restudying, but learners judge practice tests as less effective than restudying. Consequently, learners infrequently utilize testing when controlling their study and often choose to be tested only on well-learned items. In 5 experiments, we examined whether learners' choices about testing and restudying are effective for improving subsequent memory performance. Learners studied a list of word pairs and chose which items to restudy and which to test. Some of learners' choices were honored (by assigning those items to the chosen activity) and some of learners' choices were dishonored (by assigning those items to the opposite study activity). Surprisingly, and in contrast with all work to date on the metacognitive monitoring of testing effects, honoring learners' testing choices consistently resulted in better memory performance than dishonoring choices. This effect occurred principally because learners often chose to restudy difficult items, and those items did not benefit from testing. The effectiveness of learners' choices about testing casts the metacognition of testing in a new light: learners may not appreciate the benefits of testing, but they do have an understanding of circumstances in which the benefits of testing are minimal. (PsycINFO Database Record

Rasch Analysis of the Activities-Specific Balance Confidence Scale in Older Adults Seeking Outpatient Rehabilitation Services.

Background The Activities-specific Balance Confidence (ABC) scale measures confidence in performing various ambulatory activities without falling or experiencing a sense of unsteadiness. Objectives This study (1) examined the ABC scale (0-100) using Rasch analysis, (2) assessed statistically reliable change, and (3) developed a functional staging to guide clinical interpretation of a patient's improvement. Methods The authors examined rating-scale structure, item difficulty hierarchy, item fit, person-item match, separation index, differential item functioning, test precision, and unidimensionality. Additionally, this cross-sectional study of 5012 older patients seeking outpatient rehabilitation therapy in 123 clinics estimated the minimal detectable change and developed a functional staging. Results The item "walk outside on icy sidewalks" was the most difficult item, while the item "reach for a small can off a shelf at eye level" was the easiest item. Overall, average patient ability estimates of 56.2 ± 20.3 were slightly higher than the average item difficulty estimates of 45.9 ± 7.8. With a separation index equal to 3.65, the ABC scale items can differentiate individuals into 5.2 statistically distinct strata. Most ABC scale items were free of differential item functioning. For example, "walk outside on icy sidewalks" was easier for patients who were underweight. Results supported unidimensionality of the ABC scale, with the first factor explaining 77% of the total variance. The estimated minimal detectable change was 15 points. The authors provided an example of functional staging application. Conclusion Results supported sound psychometric properties and clinical usage of the ABC scale for older adults seeking outpatient rehabilitation therapy. J Orthop Sports Phys Ther 2018;48(7):574-583. Epub 30 Mar 2018. doi:10.2519/jospt.2018.8023.

Peripheral Oxytocin Predicts Higher-Level Social Cognition in Men Regardless of Empathy Quotient.

Pharmaceutical oxytocin (OT) administration is being tested as a novel treatment for social deficits in various psychiatric populations. However, little is known about how naturally occurring variation in peripheral OT relates to differences in social cognition. This study investigates whether healthy individuals with very high or very low levels of empathy differ in endogenous OT and whether OT plasma levels can predict performance in a mentalizing task. 40 healthy men were included based upon their score above the 85th or below the 15th percentile of the empathy quotient inventory 1. Participants' abilities to interpret social information was assessed via the Social Detection Task 2. Plasma OT levels were analyzed using enzyme immunoassay. OT plasma levels predicted mentalizing performance for more ambiguous social scenes (i. e., difficult items) for all participants. We found no group differences in OT plasma levels between subjects with high and low empathy. These findings confirm a link between peripheral OT and the ability to read subtle nonverbal social cues in healthy individuals, which is independent of self-reported empathy.

ANALYSIS OF MEASURES ITEMS IN DEVELOPMENT OF INSTRUMENTS SELF-ASSESSMENT (RASCH MODELING APPLICATION)

This analysis aims to determine the quality of the instrument items that have been developed in the empirical test phase one. Tests were carried out on 46 items to 219 respondents in SMA Ksatrya Jakarta. The item quality is seen from the fit or not fit and the level of difficulty of the item that has been developed. The fit or unfit criteria are seen in INFIT and OUTFIT, both MNSQ and ZSTD, and Pt-Measure Correlation values. The level of difficulty of the item is seen in the entry number column which is indicated by the magnitude of the logit value and has been sorted from the hardest to the easiest. Based on the results of analysis with the help of software winstep obtained 39 items statement fit with the model and the number of respondents 194, the three criteria above (MNSQ, ZSTD, and Pt.Measure Correlation) has been met. This means that 39 items are valid. The result of the analysis also shows the most difficult item sequence is item 5 with logit value 63,32, and the easiest item is item 44 with logit value 36,13. The resulting fit instrument must have gone through several stages of analysis. When there are items that are not fit, the item is issued, as well as the respondent. So that obtained a set of measuring instruments that are valid / fit with the model and can be used for the purposes of assessment.&#x0D; &#x0D; &#x0D; Keyword: self-assessment, infit, outfit, ZSTD, and Rasch Model.

ANALYSIS OF MEASURES ITEMS IN DEVELOPMENT OF INSTRUMENTS SELF-ASSESSMENT (RASCH MODELING APPLICATION)

This analysis aims to determine the quality of the instrument items that have been developed in the empirical test phase one. Tests were carried out on 46 items to 219 respondents in SMA Ksatrya Jakarta. The item quality is seen from the fit or not fit and the level of difficulty of the item that has been developed. The fit or unfit criteria are seen in INFIT and OUTFIT, both MNSQ and ZSTD, and Pt-Measure Correlation values. The level of difficulty of the item is seen in the entry number column which is indicated by the magnitude of the logit value and has been sorted from the hardest to the easiest. Based on the results of analysis with the help of software winstep obtained 39 items statement fit with the model and the number of respondents 194, the three criteria above (MNSQ, ZSTD, and Pt.Measure Correlation) has been met. This means that 39 items are valid. The result of the analysis also shows the most difficult item sequence is item 5 with logit value 63,32, and the easiest item is item 44 with logit value 36,13. The resulting fit instrument must have gone through several stages of analysis. When there are items that are not fit, the item is issued, as well as the respondent. So that obtained a set of measuring instruments that are valid / fit with the model and can be used for the purposes of assessment.&#x0D; &#x0D; &#x0D; Keyword: self-assessment, infit, outfit, ZSTD, and Rasch Model.

Initial training with difficult items does not facilitate category learning

In the phenomenon of transfer along a continuum (TAC), initial training on easy items facilitates later learning of a harder discrimination. TAC is a widely replicated cross-species phenomenon that is well predicted by certain kinds of associative theory. A recent report of an approximately opposite phenomenon (i.e., facilitation by initial training on hard items) poses a puzzle for such theories, but is predicted by a dual-system model (COVIS). However, across four experiments, we present substantial evidence that this counterintuitive finding was in error. Rather, the result appears to be a false positive and, as such, should not form part of the evidence base for COVIS nor be considered as a counter-example to the pervasive TAC phenomenon.

Measuring metacognitive ability based on science literacy in dynamic electricity topic

This study aims to produce an instrument of metacognition ability assessment based on science literacy on theoretically and empirically feasible dynamic electrical material. The feasibility of the assessment instrument includes theoretical validity on material, construction, and language aspects, as well as empirical validity, reliability, difficulty, distinguishing, and distractor indices. The development of assessment instruments refers to the Dick and Carey development model which includes the preliminary study stage, initial product development, validation and revision, and piloting. The instrument was tested to 32 students of class IX in SMP Negeri 20 Bandar Lampung, using the design of One Group Pretest-Postest Design. The result shows that the metacognition ability assessment instrument based on science literacy is feasible theoretically with theoretical validity percentage of 95.44% and empirical validity of 43.75% for the high category, 43.75% for the medium category, and 12.50 % for low category questions; Reliability of assessment instruments of 0.83 high categories; Difficulty level of difficult item is about 31.25% and medium category is equal to 68.75%. Item that has very good distinguishing power is 12.50%, 62.50% for good stage, and medium category is 25.00%; As well as the duplexing function on a matter of multiple choice is 80.00% including good category and 20.00% for medium category.

Exploring the Conceptual and Psychometric Properties of Alternative Assessment using the Rasch Measurement Model

The aim of this study is to develop and provide the evidence of psychometric evaluation of an instrument to measure the implementation of an alternative assessment in the context of Islamic education teachings at primary school level. In order to conceptualize alternative assessment implementation, a 32-item questionnaire was designed and administered to a group of 105 primary school teachers teaching Islamic education subject. The respondents were selected through purposive sampling. Content validity is conducted by two experts in the field from an education university. Then, the construct validity and reliability are assessed using the Rasch Measurement Model by identifying the scale rating, uni-dimensionality, item polarity, item fit, item difficulty index, item reliability, person reliability and separation index. The findings revealed that the structure calibration value with the difference of threshold is between 1.4 and 5.0. The values of PMC range from 0.46 to 0.72. All items are in the range of 0.6 to 1.4. Item C17 is removed, and it is the most difficult item. Item reliability is 0.88, person reliability is 0.97 and the separation index is 8.82 for items and 3.68 for person. The overall item quality is good. Obviously, this study does look into the implementation of AA from the sources available, the teaching strategies used by teachers and also the challenges they face in the Malaysian educational context. This validated instrument could be used for real study and also as a self-assessment tools for teachers. Teachers could then determine their strength and weaknesses.

An empirical study of the variables affecting site planning and design in green buildings

Site planning and design (SPD) is a key issue for site sustainability in green building development. This research study explores participants’ perception of SPD in green buildings. A questionnaire survey was conducted to investigate how the participants rated the importance and difficulty of SPD-related variables and items. The Kendall concordance test and Mann–Whitney U test were used to analyse and compare the responses of participants involved directly and indirectly in SPD, where the participants were divided into Group 1 and Group 2 respectively. The results showed a good consensus between the rankings provided by the two groups. The Relative Importance Index was used to calculate the scores and rankings. The top 5 most important variables and the most difficult ones to realize, and the top 5 most important items and the most difficult ones to realize, were identified and analysed respectively. Environmental protection was regarded as the most important variable, and open space was considered as the most difficult one to achieve. The most important item was water pollution reduction, and the most difficult one was rational underground space utilisation. When considering the correlation between the importance and difficulty of the items and variables, the participants show different concerns on the most important and most difficult items while hold similar opinions on the most important and most difficult variables. The findings deepen the understanding of variables which are most important and which are most difficult to achieve in the SPD of green buildings, which helps the practitioners to implement effective SPD in green buildings.

Analysis and comparison of the psychometric properties of two balance scales for elderly adults

Background/Aims: The aim of this research was to verify psychometric properties of the Berg Balance Scale and the Fullerton Advanced Balance Scale, and compare the item difficulty between the two scales. Methods: A total of 97 community-dwelling older adults participated in this study. All participants were assessed on their degree of balance ability by the Berg Balance Scale and the Fullerton Advanced Balance Scale, respectively. We identified the psychometric properties and compared the item difficulty of the two scales using the Rasch analysis. Findings: Among the items on the Berg Balance Scale, the Standing to sitting and Transfers items showed misfit statistics. The most difficult item was Standing on one foot, whereas the easiest item was Sitting unsupported. In the case of the Fullerton Advanced Balance Scale, the Standing with feet together and eyes closed, Stand on foam, eyes closed and Walk with head turns items showed misfit statistics. Also, the most difficult item was Stand on one leg (logit value, 2.93), whereas the easiest item was Turn in full circle. Among the 24 items of the combined Berg Balance Scale and Fullerton Advanced Balance Scale, 13 items (nine items for the Fullerton Advanced Balance Scale and four items on the Berg Balance Scale) had positive logit values, and 11 items (one item on the FAB and 10 on the Berg Balance Scale) had negative logit values. Conclusions: Both the Berg Balance Scale and the Fullerton Advanced Balance appear to be reliable and valid tools to assess balance function in older adults. However, the Berg Balance Scale is suitable for assessing balance ability in a group of lower functioning older adults, whereas, the Fullerton Advanced Balance is suitable for assessing balance ability in a group of higher functioning older adults.

Multiple true-false items: a comparison of scoring algorithms.

Multiple true-false (MTF) items are a widely used supplement to the commonly used single-best answer (Type A) multiple choice format. However, an optimal scoring algorithm for MTF items has not yet been established, as existing studies yielded conflicting results. Therefore, this study analyzes two questions: What is the optimal scoring algorithm for MTF items regarding reliability, difficulty index and item discrimination? How do the psychometric characteristics of different scoring algorithms compare to those of Type A questions used in the same exams? We used data from 37 medical exams conducted in 2015 (998 MTF and 2163 Type A items overall). Using repeated measures analyses of variance (rANOVA), we compared reliability, difficulty and item discrimination of different scoring algorithms for MTF with four answer options and Type A. Scoring algorithms for MTF were dichotomous scoring (DS) and two partial credit scoring algorithms, PS50 where examinees receive half a point if more than half of true/false ratings were marked correctly and one point if all were marked correctly, and PS1/n where examinees receive a quarter of a point for every correct true/false rating. The two partial scoring algorithms showed significantly higher reliabilities (αPS1/n=0.75; αPS50=0.75; αDS=0.70, αA=0.72), which corresponds to fewer items needed for a reliability of 0.8 (nPS1/n=74; nPS50=75; nDS=103, nA=87), and higher discrimination indices (rPS1/n=0.33; rPS50=0.33; rDS=0.30; rA=0.28) than dichotomous scoring and Type A. Items scored with DS tend to be difficult (pDS=0.50), whereas items scored with PS1/n become easy (pPS1/n=0.82). PS50 and Type A cover the whole range, from easy to difficult items (pPS50=0.66; pA=0.73). Partial credit scoring leads to better psychometric results than dichotomous scoring. PS50 covers the range from easy to difficult items better than PS1/n. Therefore, for scoring MTF, we suggest using PS50.

Rasch Analysis of the Korean Version of the Fullerton Advanced Balance Scale

Background: Rasch analysis has the advantage of placing both the items and the person along a single ratio scale and calibrates person ability and item difficulty onto an interval scale by logits. Therefore, Rasch analysis has been recommended as a better method for evaluating functional outcome questionnaires than traditional analyses. Objects: The aim of current study was to investigate item fit, item difficulty, rating scale, and separation index of the Korean version of the Fullerton Advanced Balance (KFAB) scale using Rasch analysis. Methods: In total, 93 patients with stroke (male=58, female=35) participated in this study. To investigate the item fit, difficulty, rating scale, and separation index of the KFAB scale, Rasch analysis was completed by the Winsteps software program. Results: In this study, all items of the KFAB scale were included in the Rasch model. The most difficult item was ‘standing with feet together and eyes closed’, and the easiest item was ‘two-footed jump’. The rating scale was a 4-point scale instead of the original 5-point scale. Person and item separation indices showed high values that can identify a person with a wide range of balance ability. Conclusion: The KFAB scale appears to be a reliable and valid tool to assess balance function in patients with stroke. Furthermore, the scale was found to discriminate among stroke patients of varying balance abilities.

Agency attributions of mental effort during self-regulated learning.

Previous results suggest that the monitoring of one's own performance during self-regulated learning is mediated by self-agency attributions and that these attributions can be influenced by poststudy effort-framing instructions. These results pose a challenge to the study of issues of self-agency in metacognition when the objects of self-regulation are mental operations rather than motor actions that have observable outcomes. When participants studied items in Experiment 1 under time pressure, they invested greater study effort in the easier items in the list. However, the effects of effort framing were the same as when learners typically invest more study effort in the more difficult items: Judgments of learning (JOLs) decreased with effort when instructions biased the attribution of effort to nonagentic sources but increased when they biased attribution to agentic sources. However, the effects of effort framing were constrained by parameters of the study task: Interitem differences in difficulty constrained the attribution of effort to agentic regulation (Experiment 2) whereas interitem differences in the incentive for recall constrained the attribution of effort to nonagentic sources (Experiment 3). The results suggest that the regulation and attribution of effort during self-regulated learning occur within a module that is dissociated from the learner's superordinate agenda but is sensitive to parameters of the task. A model specifies the stage at which effort framing affects the effort-JOL relationship by biasing the attribution of effort to agentic or nonagentic sources. The potentialities that exist in metacognition for the investigation of issues of self-agency are discussed.

Development of the Hand Assessment for Infants: evidence of internal scale validity.

The aim of this study was to develop a descriptive and evaluative assessment of upper limb function for infants aged 3 to 12 months and to investigate its internal scale validity for use with infants at risk of unilateral cerebral palsy. The concepts of the test items and scoring criteria were developed. Internal scale validity and aspects of reliability were investigated on the basis of 156 assessments of infants at 3 to 12 months corrected age (mean 7.2mo, SD 2.5) with signs of asymmetric hand use. Rasch measurement model analysis and non-parametric statistics were used. The new test, the Hand Assessment for Infants (HAI), consists of 12 unimanual and five bimanual items, each scored on a 3-point rating scale. It demonstrated a unidimensional construct and good fit to the Rasch model requirements. The excellent person reliability enabled person separation to six significant ability strata. The HAI produced an interval-level measure of bilateral hand use as well as unimanual scores of each hand, allowing a quantification of possible asymmetry expressed as an asymmetry index. The HAI can be considered a valid assessment tool for measuring bilateral hand use and quantifying side difference between hands among infants at risk of developing unilateral cerebral palsy. The Hand Assessment for Infants (HAI) measures the use of both hands and quantifies a possible asymmetry of hand use. HAI is valid for infants at 3 to 12 months corrected age at risk of unilateral cerebral palsy.

Use of Item Analysis to Improve the Quality of Single Best Answer Multiple Choice Question in Summative Assessment of Undergraduate Medical Students in Malaysia.

Background: Single best answer (SBA) as multiple-choice items are often advantageous to use for its reliability and validity. However, SBA requires good number of plausible distractors to achieve reliability. Apart from psychometric evaluation of assessment it is important to perform item analysis to improve quality of items by analysing difficulty index (DIF I), discrimination index (DI) and distractor efficiency (DE) based on number of non-functional distractors (NFD). Objective: To evaluate quality of SBA items administered in professional examination to apply corrective measures determined by DIF I, DI and DE using students’ assessment score. Method: An evaluation of post summative assessment (professional examination) of SBA items as part of psychometric assessment is performed after 86 weeks of teaching in preclinical phase of MD program. 40 SBA items and 160 distractors inclusive of key were assessed using item analysis. 136 students’ score of SBA was analysed for mean and standard deviation, DIF I, DI and DE using MS Excel 2007. Unpaired t -test was applied to determine DE in relation to DIF I and DI with level of significance. Item-total correlation (r) and internal consistency by Cronbach’s alpha and parallel-form method was also computed. Result: 15 items had DIF I=.31-.61 and 25 items had DIF I ≤.30 or ≥0.61). 26 items had DI = 0.15 - ≥.25 compared to 14 items with DI (≤0.15). There were 26 (65%) items with 1-3 NFD and 14 (35%) items without any NFD. 39 (32.50%) distractors were with choice frequency=0. Overall mean DE was 65.8% and NFD was 49 (40.5%). DE in relation to DIF I and DI were statistically significant with p = .010 and .020 respectively. Item-total correlation for most items was <.3. Internal consistency by Cronbach’s alpha in SBA test 1 and 2 was .51 and .41 respectively and constancy by parallel-form method was .57 between SBA test 1 and 2. Conclusion: The high frequency of difficult or easy items and moderate to poor discrimination suggest the need of items corrective measure. Increased number of NFD and low DE in this study indicates difficulty of teaching faculty in developing plausible distractors for SBA questions. This has been reflected in poor reliability established by alpha. Item analysis result emphasizes the need of evaluation to provide feedback and to improve quality of SBA items in assessment.

Asymptotically Normally Distributed Person Fit Indices for Detecting Spuriously High Scores on Difficult Items.

Snijders developed a family of person fit indices that asymptotically follow the standard normal distribution, when the ability parameter is estimated. So far, , U*, W*, , and from this family have been proposed in previous literature. One common property shared by , U*, and W* (also and in some specific conditions) is that they employ symmetric weight functions and thus identify spurious scores on both easy and difficult items in the same manner. However, when the purpose is to detect only the spuriously high scores on difficult items, such as cheating, guessing, and having item preknowledge, using symmetric weight functions may jeopardize the detection rates of the target aberrant response patterns. By specifying two types of asymmetric weight functions, this study proposes SHa(λ)* (λ = 1/2 or 1) and SHb(β)* (β = 2 or 3) based on Snijders's framework to specifically detect spuriously high scores on difficult items. Two simulation studies were carried out to investigate the Type I error rates and empirical power of SHa(λ)* and SHb(β)*, compared with , U*, W*, , and . The empirical results demonstrated satisfactory performance of the proposed indices. Recommendations were also made on the choice of different person fit indices based on specific purposes.

The influence of transcranial alternating current stimulation (tACS) on fluid intelligence: An fMRI study

The past decades have witnessed a huge interest in uncovering the neural bases of intelligence (e.g., Stelmack, & Houlihan, 1995; Stelmack, Knott, & Beauchamp, 2003). This study investigated the influence of transcranial alternating current stimulation (tACS) on fluid intelligence performance and corresponding brain activation. Previous findings showed that left parietal theta tACS leads to a transient increase in fluid reasoning performance. In an attempt to extend and replicate these findings, we combined theta tACS with fMRI. In a double-blind sham-controlled experiment, N=20 participants worked on two intelligence tasks (matrices and paper folding) after theta tACS was applied to the left parietal cortex. Stimulation-induced brain activation changes were recorded during task processing using fMRI. Results showed that theta tACS significantly increased fluid intelligence performance when working on difficult items in the matrices test; no effect was observed for the visuo-spatial paper folding test. Whole-brain analyses showed that left parietal brain stimulation was accompanied by lower activation in task-irrelevant brain areas. Complemental ROI analyses revealed a tendency towards lower activation in the left inferior parietal cortex. These findings corroborate the functional role of left parietal theta activity in fluid reasoning and are in line with the neural efficiency hypothesis.