A Comparison of Test-Retest Reliability and Practice Effects of Short Portable Mental State Questionnaire and Montreal Cognitive Assessment in Patients with Stroke.

OBJECTIVE: To compare the test-retest reliabilities and minimal detectable change (MDC) of the Short Portable Mental State Questionnaire (SPMSQ) and the Montreal Cognitive Assessment (MoCA) in patients with stroke. METHODS: 63 patients were recruited from 1 medical center. The SPMSQ and MoCA were administered twice, 2 weeks apart. RESULTS: Both measures showed high intraclass correlation coefficients (SPMSQ: 0.87; MoCA: 0.89) and acceptable MDC%s (SPMSQ: 14.8%; MoCA: 19.6%). A small correlation (r = 0.30) was found between the absolute difference and average in each pair of assessments in the SPMSQ, which was close to the criterion of heteroscedasticity. A small practice effect was observed in the MoCA (Cohen's d = 0.30). CONCLUSION: The SPMSQ demonstrated smaller random measurement error and an absence of practice effect. When comparing the psychometric properties of the SPMSQ and MoCA as outcome measures for assessing cognitive function in patients with stroke, the SPMSQ appears to be a more suitable choice than the MoCA.

Practice-induced SNARC: evidence from a null-SNARC sample.

The mental representation of numbers inherently involves a spatial organization, often positioning smaller numbers to the left and larger numbers to the right. The SNARC effect, characterized by faster responses to small numbers using the left hand and vice versa for large numbers, is typically attributed to this left-to-right oriented mental number line (MNL). However, the direction of the SNARC effect seems to rely on reading direction, with most research exploring these mechanisms conducted within left-to-right reading cultures where the SNARC effect is prevalent. This study takes advantage of a sample from a left-to-right reading culture that does not exhibit the SNARC effect, allowing us to isolate and elucidate the stand-alone effects of recent experiences on SNARC. Therefore, the current study aims to investigate how MNL-compatible and MNL-incompatible practices induce an effect within a sample lacking the SNARC effect. To accomplish this, we reinvited the individuals from the sample which had previously shown no SNARC, and retested those who agreed to take part in the current study after an MNL-compatible or MNL-incompatible practice manipulation. The findings revealed an absence of the SNARC effect with MNL-compatible practices. Conversely, MNL-incompatible practices yielded a reverse SNARC effect. These results prompt a discussion on SNARC mechanisms within the framework of practice effects.

Practice effect and test-retest reliability of the Wechsler Memory Scale-Fourth Edition in people with dementia.

BACKGROUND: The Wechsler Memory Scale-Fourth Edition (WMS-IV) has been widely used to assess memory function in people with dementia. The older adult battery of the WMS-IV includes four indices and seven subtests. The aims of this study were to examine the practice effect and test-retest reliability and calculate the reliable change index modified for practice (RCIp) for the indices and subtests of the older adult battery of the WMS-IV for people with dementia. METHODS: Fifty-six participants completed the WMS-IV twice, two weeks apart. The practice effect was investigated using effect size (Cohen's d) and bootstrapping mixed design analysis of variance while considering the severity of dementia. The test-retest reliability was estimated using intraclass correlation coefficient (ICC). RESULTS: The results showed non-significant practice effects with Cohen's d < 0.20 in different severities of dementia on two indices and five subtests. The ICC values of these indices and subtests were 0.82-0.85 and 0.57-1.00, respectively. The other two indices (i.e., auditory memory and immediate memory) and two subtests (i.e., logical memory delayed recall and visual reproduction immediate recall) demonstrated small to moderate practice effect (d = 0.46-0.74) for people with mild severity of dementia. CONCLUSION: On the whole, the WMS-IV has no to moderate practice effects and moderate to excellent test-retest reliability in people with dementia. The values of the RCIp with 95% confidence interval for the indices and subtests were provided in this study, which are useful to clinicians and researchers for interpreting the real score change in persons with dementia. The two indices (i.e., auditory memory and immediate memory) and two subtests (i.e., logical memory delayed recall and visual reproduction immediate recall) with noticeable practice effect should be used with caution when assessing memory function repeatedly in people with mild severity of dementia.

Mayo-PACC: A parsimonious preclinical Alzheimer's disease cognitive composite comprised of public-domain measures to facilitate clinical translation.

INTRODUCTION: We aimed to define a Mayo Preclinical Alzheimer's disease Cognitive Composite (Mayo-PACC) that prioritizes parsimony and use of public domain measures to facilitate clinical translation. METHODS: Cognitively unimpaired participants aged 65 to 85 at baseline with amyloid PET imaging were included, yielding 428 amyloid negative (A-) and 186 amyloid positive (A+) individuals with 7 years mean follow-up. Sensitivity to amyloid-related cognitive decline was examined using slope estimates derived from linear mixed models (difference in annualized change across A+ and A- groups). We compared differences in rates of change between Mayo-PACC and other composites (A+ > A- indicating more significant decline in A+). RESULTS: All composites showed sensitivity to amyloid-related longitudinal cognitive decline (A+ > A- annualized change p < 0.05). Comparisons revealed that Mayo-PACC (AVLT sum of trials 1-5+6+delay, Trails B, animal fluency) showed comparable longitudinal sensitivity to other composites. DISCUSSION: Mayo-PACC performs similarly to other composites and can be directly translated to the clinic.

Practice effect and test-retest reliability of the Mini-Mental State Examination-2 in people with dementia.

BACKGROUND: The Mini-Mental State Examination-Second Edition (MMSE-2) consists of three visions: a brief version (MMSE-2:BV), a standard version (MMSE-2:SV), and an expanded version (MMSE-2: EV). Each version was equipped with alternate forms (blue and red). There was a lack of evidence on the practice effect and test-retest reliability of the three versions of the MMSE-2, limiting its utility in both clinical and research settings. The purpose of this study was to examine the practice effect and test-retest reliability of the MMSE-2 in people with dementia. METHODS: One hundred and twenty participants were enrolled, of which 60 were administered with the blue form twice (i.e., the same-form group, [SF group]) and 60 were administered with the blue form first and then the red form (alternate-form group, [AF group]). The practice effect was evaluated using a paired t-test and Cohen's d. The test-retest reliability was examined using the intraclass correlation coefficient (ICC). RESULTS: For the practice effects, in the SF group, no statistically significant differences were found for the MMSE-2:BV and MMSE-2: EV total scores and eight subtests (p = 0.061-1.000), except for the MMSE-2:SV total score (p = 0.029). In the AF group, no statistically significant differences were found for all three versions of the total scores and subtests (p = 0.106-1.000), except for the visual-constructional ability subtest (p = 0.010). Cohen's d of all three versions' total scores and subtests were 0.00-0.20 and 0.00-0.26 for SF group and AF group, respectively. For the test-retest reliability, ICC values for all three versions and eight subtests in SF and AF groups were 0.60-0.93 and 0.56-0.93, respectively. CONCLUSION: Our results demonstrated that the practice effect could be minimized when alternate forms of the MMSE-2 were used. The MMSE-2 had good to excellent test-retest reliability, except for three subtests (i.e., visual-constructional ability, registration, and recall). Caution should be taken when interpreting the results of visual-constructional ability, registration, and recall subtests of the MMSE-2.

Test-retest reliability and practice effect of the Leuven Perceptual Organisation Screening Test.

AbstractVisual diagnostic tests must have a high degree of consistency in their measurements (high reliability) to ensure accurate assessment of perceptual abilities. The current study assessed test-retest reliability and practice effects in the Leuven Perceptual Organisation Screening Test (L-POST) in 144 healthy volunteers, with time intervals between 0 and 756 days. We used Pearson's and intraclass correlation analysis, Bland-Altman analysis and multilevel modelling. Results from our analyses converged and supported an adequate reliability of the L-POST. Multilevel modelling demonstrated an absence of practice effect, suggesting that the L-POST is suitable for repeat administration. This study suggests that the L-POST has adequate reliability and is suitable for repeat administration even at short intervals. This study provides the basis for a more systematic evaluation for neuropsychological assessments, which can lead to the development of more reliable assessment batteries.

Effective external reminders impair the practice effect of time-based prospective memory.

The practice effect of time-based prospective memory (TBPM) refers to the phenomenon that TBPM task performance can be significantly improved by repetitive behavioural training. However, reminders are a common strategy for people to perform TBPM tasks in daily life. A large amount of evidence shows that reminders can improve TBPM performance when individuals pay less attention to time information. However, the present study was the first to explore whether external reminders might simultaneously impede the practice effect of TBPM. In this study, 81 undergraduate students were randomly assigned to control group (N = 27, Mage  = 20.00, SDage  = 1.04), reminder group (N = 26, Mage  = 20.35, SDage  = 1.70) and non-reminder group (N = 28, Mage  = 20.25, SDage  = 1.17). In the training stage, the reminder group could receive effective external reminders, while the non-reminder group could not. The results of the training stage revealed that compared with the non-reminder group, the reminder group had fewer time monitoring times and better TBPM performance. In the testing stage, when reminders were removed from the reminder group, we found that compared with the control group without TBPM training, the TBPM performance of the reminder group failed to improve, while that of the non-reminder group improved significantly. Meanwhile, the time estimation ability of the reminder group was not as improved as that of the non-reminder group.

Test-Retest Reliability, Training, and Detraining Effects Associated With the Dynavision D2™ Mode A Visuomotor Reaction Time Test.

CONTEXT: The Dynavision D2™ Mode A test (ModeA) is a 1-minute reaction time (RT) test commonly used in sports science research and clinical rehabilitation. However, there is limited data regarding the effect of repeated testing (ie, training) or subsequent periods of no testing (ie, detraining) on test-retest reliability and RT performance. Therefore, the purpose of this study was to examine the test-retest reliability, training, and detraining effects associated with the D2™ ModeA test. DESIGN: Repeated measures/reliability. METHODS: Twenty-four recreationally active men and women completed 15 training sessions consisting of 2 ModeA tests per session (30 tests). The participants were then randomized to either 1 or 2 weeks of detraining prior to completing 15 retraining sessions (30 tests). The training and retraining periods were separated into 10 blocks for analysis (3 tests per block). The number of hits (hits) and the average RT per hit (AvgRT) within each block were used to determine RT performance. Intraclass correlation coefficients, SEM, and minimum difference were used to determine reliability. Repeated-measures analysis of variance/analysis of covariance were used to determine training and detraining effects, respectively. RESULTS: The ModeA variables demonstrated excellent test-retest reliability (intraclass correlation coefficient2,3 > .93). Significant improvements in hits and AvgRT were noted within training blocks 1 to 5 (P < .05). No further improvements in RT performance were noted between training blocks 6 through 10. There was no effect of detraining period on RT. The RT performance was not different between blocks during retraining. CONCLUSIONS: It appears that 15 tests are necessary to overcome the training effect and establish reliable baseline performance for the ModeA test. Detraining for 1 to 2 weeks did not impact RT performance. The authors recommend that investigators and clinicians utilize the average of 3 tests when assessing RT performance using the D2 ModeA test.

Age-Related Decreases in the Retrieval Practice Effect Directly Relate to Changes in Alpha-Beta Oscillations.

The retrieval (or testing) of information leads to better memory performance compared with reencoding. This phenomenon is known as "testing effect" or "retrieval practice effect" and has been primarily described in behavioral studies with healthy young subjects. However, possible age-related changes and their associated underlying neural processes, in particular neural oscillations, remain unclear. To address this issue, we used a previously established paradigm in healthy young (N = 27) and elderly (N = 28) male and female human adults while their brain activity was being recorded using EEG. Subjects viewed prefamiliarized scene images intermixed with new scenes and classified them as indoor versus outdoor (encoding task) or old versus new (retrieval task). Subsequently, subjects performed a recognition memory task 10 min and 24 h after encoding. Behaviorally, both age groups showed the testing effect at both time points but, importantly, it was less pronounced in the elderly. At the neural level, the retrieval compared with the encoding task was accompanied by power decreases in the alpha (9-12 Hz) and beta bands (13-30 Hz), possibly reflecting task demands, and this difference was more pronounced in the elderly. Finally, a correlation analysis revealed that those elderly who displayed a more pronounced testing effect exhibited a neural pattern that was more similar to the younger subjects. These findings provide evidence that the testing effect decreases across the life span, and they suggest that changes in alpha-beta oscillations play a direct role.SIGNIFICANCE STATEMENT Learning new and retrieving old information is part of everyday human life. Understanding how learning processes can be optimized therefore has direct applications in the realm of educational and rehabilitative contexts. Here, we show that retrieval practice is a strategy to optimize encoding into long-term memory in both young and elderly humans. Importantly, retrieval practice was significantly reduced in the elderly and closely related to changes in alpha (9-13 Hz) and beta band (13-30 Hz) oscillations. Our findings suggest that decreased retrieval practice effects across the life span contribute to, and may reflect, age-related declines in memory performance. They further provide new insights into the underlying neural mechanisms and point toward future avenues for neuro-modulatory interventions.

Effects of Varied Surgical Simulation Training Schedules on Motor-Skill Acquisition.

There have been many studies to evaluate the effect of training schedules on retention; however, these usually compare only 2 drastically different schedules, massed and distributed, and they have tended to look at declarative knowledge tasks. This study examined learning on a laparoscopic surgery simulator using a set of procedural or perceptual-motor tasks with some declarative elements. The study used distributed, massed, and 2 hybrid-training schedules that are neither distributed nor massed. To evaluate the training schedules, 23 participants with no previous laparoscopic experience were recruited and randomly assigned to 1 of the 4 training schedules. They performed 3 laparoscopic training tasks in eight 30-minute learning sessions. We compared how task time decreased with each schedule in a between-participants design. We found participants in all groups demonstrated a decrease in task completion time as the number of training sessions increased; however, there were no statistically significant differences in participants' improvement on task completion time between the 4 different training schedule groups, which suggested that time on task is more important for learning these tasks than the training schedule.

The role of emotion arousal in the retrieval practice effect.

Many studies have shown that practicing retrieval produces better memory retention compared to restudy. Though previous literature has provided valuable insights about the retrieval practice effect, it is still unclear how emotion arousal influences the retrieval practice effect, and whether the effect would be manifested in recollection or familiarity processes. To answer these questions, in the current study, negative and neutral words were used as stimuli and participants were asked to perform a recognition test or restudy the words after initial study. At the end of the experiment, a final recognition test with involving the remember-know paradigm was shown. Behavioral data were collected with EEG recorded throughout the experiment. The behavioral retrieval practice effect was only found for the neutral but not the negative words. Consistently, significant ERP differences between the restudy and retrieval practice conditions were only found for neutral, but not negative items, which was a component from 700 to 900 ms at left-posterior electrode cluster. Moreover, we found that the effects of emotion arousal on the retrieval practice effect were mainly reflected in the recollection process. These findings provide behavioral and neural evidence that emotion arousal can influence the retrieval practice effect.

Aging-related changes of cognitive performance and stress regulation in high functioning elderly individuals.

This article aims to analyse long-term changes in cognitive performance and psychophysiological stress regulation in a specific sample of 10 young-old (age at pre-test: M ± SD = 63.2 ± 1.5) and 12 old-old (age at pre-test: M ± SD = 69 ± 2) persons possessing a high psychosocial status and a physically active lifestyle. Psychophysiological parameters were recorded prior to, during, and after the administration of a cognitive performance test battery. The measurements took place three times within a 6-month period, and again 6 years later in a follow-up test. Considering practice and habituation effects, findings provide no compelling evidence of an aging-associated cognitive decline in attention, multiple choice reaction performance, and information processing speed, either in the young-olds, or in the old-olds. Furthermore, psychophysiological stress regulation showed no long-term alteration regarding skin conductance level and heart rate. Based on these findings, it is assumed that psychosocial health and physical activity might contribute to the preservation of cognitive abilities and stress regulation into the 70s. Finally, this study demonstrated the significance of considering practice and habituation effects elicited through test repetitions in order to estimate long-term effects.

Why does interleaving improve math learning? The contributions of discriminative contrast and distributed practice.

Interleaved practice involves studying exemplars from different categories in a non-systematic, pseudorandom order under the constraint that no two exemplars from the same category are presented consecutively. Interleaved practice of materials has been shown to enhance test performance compared to blocked practice in which exemplars from the same category are studied together. Why does interleaved practice produce this benefit? We evaluated two non-mutually exclusive hypotheses, the discriminative-contrast hypothesis and the distributed-practice hypothesis, by testing participants' performance on calculating the volume of three-dimensional geometric shapes. In Experiment 1, participants repeatedly practiced calculating the volume of four different-sized shapes according to blocked practice, interleaved practice, or remote-interleaved practice (which involved alternating the practice of volume calculation with non-volume problems, like permutations and fraction addition). Standard interleaving enhanced performance compared to blocked practice but did not produce enhanced performance compared to remote interleaving. In Experiment 2, we replicated this pattern and extended the results to include a remote-blocked group, which involved blocking volume calculation with non-volume problems. Performance on key measures was better for remote-interleaved groups compared to remote-blocked groups, a finding that supports the distributed-practice hypothesis.

Examining Practice and Learning Effects With Serial Administration of the Clinical Reaction Time Test in Healthy Young Athletes.

CONTEXT: The clinical reaction time (RTclin) test has been recommended as a valid test for assessing concussion and determining recovery of reaction time function following concussion. However, it is unknown whether repeat assessment, as is used in postconcussion testing, is affected by learning or practice phenomena. OBJECTIVE: To determine if a practice or learning effect is present with serial administration of the RTclin test. DESIGN: Randomized control trial. SETTING: University athletic training clinics. PARTICIPANTS: A total of 112 healthy collegiate athletes (age = 19.46 [1.34] y). INTERVENTIONS: The control group completed the RTclin test on days 1 and 60. The experimental group completed the RTclin test on days 1, 2, 3, 7, and 60. MAIN OUTCOME MEASURE: Reaction time as measured with the RTclin test. RESULTS: The difference in RTclin test performance from day 1 to day 60 was not significant (mean change = -2.77 [14.46] ms, P = .42, 95% confidence intervals, -6.40 to 0.862) between groups. The experimental group experienced significant improvement (λ = 0.784, F4,49 = 3.365, P = .02, η2 = .216, power = 0.81) with acute repeat testing. However, post hoc analysis did not reveal a significant difference between scores during the 5 test periods. CONCLUSIONS: The results suggest serial administration of the RTclin test does not produce a practice or learning effect. Clinicians, however, should be cautious as the results do provide evidence patients may demonstrate improved scores when testing occurs on repetitive days after initial exposure to the test.

Role of taxanes in chemotherapy-related cognitive impairment: A prospective longitudinal study.

PURPOSE: The aim of this study is to elucidate the role of taxanes on cognition when they are administered as a part of the treatment with a fluorouracil, epirubicin and cyclophosphamide (FEC) regimen for breast cancer (BC). METHODS: Two groups of women (n = 51) with a novel diagnostic of BC that were treated with a combination of FEC alone (6 cycles of FEC) or with taxanes (4 cycles of FEC plus 8 cycles of taxanes) were compared at three moments: before chemotherapy, after its completion (short-term evaluation) and at a mean of 74.5 weeks from baseline as a long-term evaluation. RESULTS: Both groups showed worsening in tests of attention and executive functions on the short-term assessment, with the group treated with taxanes showing more number of affected cognitive measures at this time point, including verbal learning and speed measures. At the long-term evaluation, cognitive dysfunction was still found in attention and executive functions in both groups. CONCLUSION: Our results suggest that chemotherapy for BC with a FEC regimen can have a negative effect on cognition. Acute deficits seem to be larger when taxanes are added, but treatment seems to affect cognition also at long term.

Evaluation of practice effect on neuropsychological measures among persons with and without HIV infection in northern India.

An evaluation of the effects of HIV infection on neurocognition over time is important for understanding disease progression. Changes in cognitive function can be evaluated longitudinally by using neuropsychological testing at repeated intervals. The assessment of change over time, however, is complicated by the potentially confounding influence of learning on repeated test administrations, often referred to as practice effect. In this study, we present data on testing of persons with or without HIV infection on a battery administered at study baseline and repeated 1 year later. Results suggest that practice effects may be diminished in persons with HIV infection compared to without it. This appears to be true even among those with relatively intact immune functioning as measured by CD4 count.

White matter and memory in healthy adults: Coupled changes over two years.

Numerous cross-sectional studies have used diffusion tensor imaging (DTI) to link age-related differences in white matter (WM) anisotropy and concomitant decrements in cognitive ability. Due to a dearth of longitudinal evidence, the relationship between changes in diffusion properties of WM and cognitive performance remains unclear. Here we examine the relationship between two-year changes in WM organization and cognitive performance in healthy adults (N=96, age range at baseline=18-79 years). We used latent change score models (LCSM) to evaluate changes in age-sensitive cognitive abilities - fluid intelligence and associative memory. WM changes were assessed by fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD) in WM regions that are considered part of established memory networks and exhibited individual differences in change. In modeling change, we postulated reciprocal paths between baseline measures and change factors, within and between WM and cognition domains, and accounted for individual differences in baseline age. Although baseline cross-sectional memory performance was positively associated with FA and negatively with RD, longitudinal effects told an altogether different story. Independent of age, longitudinal improvements in associative memory were significantly associated with linear reductions in FA and increases in RD. The present findings demonstrate the sensitivity of DTI-derived indices to changes in the brain and cognition and affirm the importance of longitudinal models for evaluating brain-cognition relations.

Sequential brief neuropsychological evaluation of migraineurs is identical to controls.

BACKGROUND: Evidence of attack-related cognitive dysfunction in migraine is growing. Controversy exists on whether cognitive dysfunction, mainly executive, may persist between attacks. Measuring the impact of cognitive function is gaining importance in clinical and research settings in migraine. OBJECTIVE: To compare the performance of interictal migraine patients to controls in an assembled neuropsychological battery focused on executive functions and to study the practice effect of its repeated applications. METHOD: Assembly of the battery that was then applied twice within 6 weeks to interictal migraineurs and matched healthy controls. RESULTS: Migraine patients (n = 24) and controls (n = 24) had similar performance in both applications of the battery. There was a slight practice effect between the first and second evaluation, significant in Stroop Interference test (P = 0.002, multiplicity corrected); a meaningful score change was determined for each raw test scores. CONCLUSIONS: Interictal migraineurs and controls performance is identical in a brief cognitive battery focused on executive functions. Repeated applications produced a practice effect that was quantified.

Predictors of Retest Effects in a Longitudinal Study of Cognitive Aging in a Diverse Community-Based Sample.

Better performance due to repeated testing can bias long-term trajectories of cognitive aging and correlates of change. We examined whether retest effects differ as a function of individual differences pertinent to cognitive aging: race/ethnicity, age, sex, language, years of education, literacy, and dementia risk factors including apolipoprotein E ε4 status, baseline cognitive performance, and cardiovascular risk. We used data from the Washington Heights-Inwood Columbia Aging Project, a community-based cohort of older adults (n=4073). We modeled cognitive change and retest effects in summary factors for general cognitive performance, memory, executive functioning, and language using multilevel models. Retest effects were parameterized in two ways, as improvement between the first and subsequent testings, and as the square root of the number of prior testings. We evaluated whether the retest effect differed by individual characteristics. The mean retest effect for general cognitive performance was 0.60 standard deviations (95% confidence interval [0.46, 0.74]), and was similar for memory, executive functioning, and language. Retest effects were greater for participants in the lowest quartile of cognitive performance (many of whom met criteria for dementia based on a study algorithm), consistent with regression to the mean. Retest did not differ by other characteristics. Retest effects are large in this community-based sample, but do not vary by demographic or dementia-related characteristics. Differential retest effects may not limit the generalizability of inferences across different groups in longitudinal research.

Practice effects and test-re-test reliability of the Five Digit Test in patients with stroke over four serial assessments.

OBJECTIVES: To investigate practice effect and test-re-test reliability of the Five Digit Test (FDT) over four serial assessments in patients with stroke. DESIGN: Single-group repeated measures design. METHODS: Twenty-five patients with stroke were administered the FDT in four consecutive assessments every 2 weeks. The FDT contains four parts with five indices: 'basic measures of attention and processing speed', 'selective attention', 'alternating attention', 'ability of inhibition' and 'ability of switching'. RESULTS: The five indices of the FDT showed trivial-to-small practice effects (Cohen's d = 0.03-0.47) and moderate-to-excellent test-re-test reliability (intra-class correlation coefficient = 0.59-0.97). Practice effects of the five indices all appeared cumulative, but one index, 'basic measures of attention and processing speed', reached a plateau after the second assessment. The minimum and maximum values of the 90% confidence interval (CI) of reliable change index modified for practice (RCIp) for this index were [-17.6, 11.2]. CONCLUSIONS: One of five indices of the FDT reached a plateau, whose minimum and maximum values of the 90% CI RCIp are useful to determine whether the change in an individual's score is real. However, clinicians and researchers should be cautious when interpreting the test results of these four indices over repeated assessments.