Limitations Of The Analysis Of Variance

Conditions under which the analysis of variance will yield inexact p-values or would be inferior in power to a permutation test are investigated. The findings for the one-way design are consistent with and extend those of Miller (1980)

Show jumping judges view on parental involvement in pony competitions for young riders

Equestrian is the second largest youth sport in Sweden, over half a million Swedes are involved in the sport. Children often start their show jumping career in pony classes at smaller shows. In Sweden children are allowed to compete pony until the year they turn 20. The equestrian sport is growing in Sweden and the shows are getting larger, for younger riders that also means an increase of parental involvement. Showjumping is expensive and takes a lot of time, which can put an economical pressure on their families. Young riders are dependent on parents to support them with the finances and transport. Without the parental involvement the Swedish pony sport wouldn’t exist. Ponies are bought for generous amounts of money and the young riders can then feel pressured to produce great results because of the amount of money their parents have invested. Previous results of the pony could also be stressful for the young rider to accomplish, to exceed their own and others expectations. Previous studies have been done out of child’s perspective and parents perspective but never out of a judge’s perspective. This studies purpose was to investigate jumping judge’s views on parental involvement in show jumping competitions for young riders. The study contributes more insight in how parenting involvement affects the young riders at competitions. Five judges were selected to participate in the study, they where all selected by their many years of experience in Swedish pony sport. All judges had participated in shows on at least national level this year and last year they did between 15 and 63 competitions days. All the judges were interviewed and given time to read and reflect on the questions beforehand. The majority of the results show that parental involvement is mostly supportive. However, there are some improper behaviors that can be perceived as pressing, and which may affect children negatively. This type of behavior is often due to lack of knowledge and understanding regarding horses in general and is often seen in parents with lack of former horse experience. By establishing a good routine that gives both parents and the young riders a sense of security you should be able to reduce the amount of stress. Less stress would increase the child’s positive experience and make it more likely for the child to proceed and evolve in the sport. Results also suggest that more support from the coaches, would make it easier for the parents to take a supportive parenting role instead of maneuvering both parenting and coaching. The conclusion of the study was that most of the results show that the parenting involvement is seen supportive and has a positive effect on children. It does occur that some negative behavior does exist, but its seen as a minority. However, there are shortcomings regarding the parent’s knowledge which affects the parent’s behavior and the judges would like to see more commitment from coaches at competitions.I denna studie studeras hoppdomarens upplevelser av föräldraengagemanget på ponnyhopptävlingar. Det underliggande problemet till detta var att det genom tidigare studier är känt att föräldrars engagemang har förekommit som pressande inom barn och ungdomsidrott. Tidigare studier har undersökt föräldrar och barns perspektiv på föräldraengagemang men ingen studie har tidigare använt sig av ett domarperspektiv. Fem domare valdes ut för att delta i studien, varav samtliga hade varit aktiva inom svensk ponnysport under många år. För att samla in materialet genomfördes djupintervjuer. Domarnas primära åsikt var att det saknades kunskap hos många av föräldrarna på tävlingsplatserna. Den bristande kunskapen som kunde vara den bidragande faktorn till hur föräldrar beter sig på tävling. Domarna upplevde att föräldrarna var välvilliga i sitt engagemang men att det ibland blev för mycket, och då uppfattades som pressande. I en del fall blir föräldrarna den drivande faktorn för sporten och kan på så sätt underminera barnens intresse och glädje för sporten. När barnen inte får vara den drivande faktorn för intresset, kan det i sin tur kan leda till att intresset minskar och barnen slutar med sin sport. Föräldraengagemanget upplevdes vara störst precis innan start med alla förberedelser. Framhoppningen och framridningen är där domarna såg mest engagemang från föräldrarna, både positiv och negativt. Domarna upplevde att framhoppningen medförde mycket stress ofta på grund av okunskap hos föräldrar. Ibland uppstår även rent farliga situationer på grund av den okunskap som finns. Om barnen och föräldrarna skulle utveckla sin kunskap hur de skall genomföra en tävlingsdag på bästa sätt så skulle stressnivån reduceras. För mycket stress minskar barnets glädje för sporten, positiv feedback från föräldrar kan göra att barnet känner sig nöjdare med sin prestation och därmed ökad glädje. Den glädje och gemenskap som finns på tävling är en mycket viktig del i barnens utövande inom sporten och borde enligt studiens resultat lyftas fram ännu mer inom all barnidrott. Det framgår även att det här är något som fler föräldrar och barn ska ta i beaktning i själva tävlingssituationen. Barn- och ungdomsidrott vilar på att barn ska känna glädje av sin idrott. Resultatet visade även på att om man skulle kunna lägga över en del av ansvaret på barnets tränare så skulle det bli lättare för föräldrarna att stanna i en föräldraroll och stötta sina barn utan att behöva coacha eller inta en tränarroll. Om tränarna lade större vikt vid att engagera sig i sina ryttares tävlingsrutin och planering så skulle färre misstag ske, förutsatt att eleverna och föräldrarna lyssnar och tar till sig av informationen. Slutsatsen av den här studien är att föräldraengagemang uppfattas till mesta del som positivt och stöttande men att det förekommer en del ofördelaktigt beteende hos föräldrar som kan uppfattas som pressande. Dessa upplevs vara en minoritet i sporten. Däremot saknas det många gånger kunskap hos föräldrar som påverkar deras beteende och att de behöver mer stöd i själva tävlingssituationen. Här föreslår domarna mer stöttning av tränare på plats

Parametric Analyses In Randomized Clinical Trials

One salient feature of randomized clinical trials is that patients are randomly allocated to treatment groups, but not randomly sampled from any target population. Without random sampling parametric analyses are inexact, yet they are still often used in clinical trials. Given the availability of an exact test, it would still be conceivable to argue convincingly that for technical reasons (upon which we elaborate) a parametric test might be preferable in some situations. Having acknowledged this possibility, we point out that such an argument cannot be convincing without supporting facts concerning the specifics of the problem at hand. Moreover, we have never seen these arguments made in practice. We conclude that the frequent preference for parametric analyses over exact analyses is without merit. In this article we briefly present the scientific basis for preferring exact tests, and refer the interested reader to the vast literature backing up these claims. We also refute the assertions offered in some recent publications promoting parametric analyses as being superior in some general sense to exact analyses. In asking the reader to keep an open mind to our arguments, we are suggesting the possibility that numerous researchers have published incorrect advice, which has then been taught extensively in schools. We ask the reader to consider the relative merits of the arguments, but not the frequency with which each argument is made

Caveats for using statistical significance tests in research assessments

This paper raises concerns about the advantages of using statistical significance tests in research assessments as has recently been suggested in the debate about proper normalization procedures for citation indicators. Statistical significance tests are highly controversial and numerous criticisms have been leveled against their use. Based on examples from articles by proponents of the use statistical significance tests in research assessments, we address some of the numerous problems with such tests. The issues specifically discussed are the ritual practice of such tests, their dichotomous application in decision making, the difference between statistical and substantive significance, the implausibility of most null hypotheses, the crucial assumption of randomness, as well as the utility of standard errors and confidence intervals for inferential purposes. We argue that applying statistical significance tests and mechanically adhering to their results is highly problematic and detrimental to critical thinking. We claim that the use of such tests do not provide any advantages in relation to citation indicators, interpretations of them, or the decision making processes based upon them. On the contrary their use may be harmful. Like many other critics, we generally believe that statistical significance tests are over- and misused in the social sciences including scientometrics and we encourage a reform on these matters.Comment: Accepted version for Journal of Informetric

It Takes Time to Be Cool:On the Relationship between Hyperthermia and Body Cooling in a Migrating Seaduck

The large amount of energy expended during flapping flight is associated with heat generated through the increased work of the flight muscles. This increased muscle work rate can manifest itself in core body temperature (Tb) increase of 1–2°C in birds during flight. Therefore, episodic body cooling may be mandatory in migratory birds. To elucidate the thermoregulatory strategy of a short-distance migrant, common eiders (Somateria mollissima), we implanted data loggers in the body cavity of wild birds for 1 year, and report information on Tb during their entire migration for 19 individuals. We show that the mean body temperature during flight (TbMean) in the eiders was associated with rises in Tb ranging from 0.2 to 1.5°C, largely depending on flight duration. To understand how eiders are dealing with hyperthermia during migration, we first compare, at a daily scale, how Tb differs during migration using a before-after approach. Only a slight difference was found (0.05°C) between the after (40.30°C), the before (40.41°C) and the migration (40.36°C) periods, indicating that hyperthermia during flight had minimal impact at this time scale. Analyses at the scale of a flight cycle (flight plus stops on the water), however, clearly shows that eiders were closely regulating Tb during migration, as the relationship between the storage of heat during flight was highly correlated (slope = 1) with the level of heat dumping during stops, at both inter-individual and intra-individual levels. Because Tb at the start of a flight (TbStart) was significantly and positively related to Tb at the end of a flight (TbEnd), and the maximal attained Tb during a flight (TbMax), we conclude that in absence of sufficient body cooling during stopovers, eiders are likely to become increasingly hyperthermic during migration. Finally, we quantified the time spent cooling down during migration to be 36% of their daily (24 h) time budget, and conclude that behavioral body cooling in relation to hyperthermia represents an important time cost

Does hyperthermia constrain flight duration in a short-distance migrant?

While some migratory birds perform non-stop flights of over 11 000 km, many species only spend around 15% of the day in flight during migration, posing a question as to why flight times for many species are so short. Here, we test the idea that hyperthermia might constrain flight duration (FD) in a short-distance migrant using remote biologging technology to measure heart rate, hydrostatic pressure and body temperature in 19 migrating eider ducks (Somateria mollissima), a short-distance migrant. Our results reveal a stop-and-go migration strategy where migratory flights were frequent (14 flights day(−1)) and short (15.7 min), together with the fact that body temperature increases by 1°C, on average, during such flights, which equates to a rate of heat storage index (HSI) of 4°C h(−1). Furthermore, we could not find any evidence that short flights were limited by heart rate, together with the fact that the numerous stops could not be explained by the need to feed, as the frequency of dives and the time spent feeding were comparatively small during the migratory period. We thus conclude that hyperthermia appears to be the predominant determinant of the observed migration strategy, and suggest that such a physiological limitation to FD may also occur in other species. This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight’

Changes in the Seasonality of Precipitation over the Contiguous USA

Consequences of possible changes in annual total precipitation are dictated, in part, by the timing of precipitation events and changes therein. Herein, we investigated historical changes in precipitation seasonality over the US using observed station precipitation records to compute a standard seasonality index (SI) and the day of year on which certain percentiles of the annual total precipitation were achieved (percentile day of year). The mean SI from the majority of stations exhibited no difference in 1971–2000 relative to 30-year periods earlier in the century. However, analysis of the day of year on which certain percentiles of annual total precipitation were achieved indicated spatially coherent patterns of change. In some regions, the mean day of the year on which the 50th percentile of annual precipitation was achieved differed by 20–30 days between 1971–2000 and both 1911–1940 and 1941–1970. Output from the 10-Atmosphere-Ocean General Circulation Models (AOGCM) simulations of 1971–2000, 2046–2065, and 2081–2100 was used to determine whether AOGCMs are capable of representing the seasonal distribution of precipitation and to examine possible future changes. Many of the AOGCMs qualitatively captured spatial patterns of seasonality during 1971–2000, but there was considerable divergence between AOGCMs in terms of future changes. In both the west and southeast, 7 of 10 AOGCMs indicated later attainment of the 50th percentile accumulation in 2047–2065, implying a possible reversal of the twentieth-century tendency toward relative increases in precipitation receipt during winter and early spring over the southeast. However, this is also a region characterized by considerable interannual variability in the percentile day of year during the historical period

Observational uncertainty and regional climate model evaluation: A pan-European perspective

The influence of uncertainties in gridded observational reference data on regional climate model (RCM) evaluation is quantified on a pan-European scale. Three different reference data sets are considered: the coarse-resolved E-OBS data set, a compilation of regional high-resolution gridded products (HR) and the European-scale MESAN reanalysis. Five high-resolution ERA-Interim-driven RCM experiments of the EURO-CORDEX initiative are evaluated against each of these references over eight European sub-regions and considering a range of performance metrics for mean daily temperature and daily precipitation. The spatial scale of the evaluation is 0.22°, i.e. the grid spacing of the coarsest data set in the exercise (E-OBS). While the three reference grids agree on the overall mean climatology, differences can be pronounced over individual regions. These differences partly translate into RCM evaluation uncertainty. For most cases observational uncertainty is smaller than RCM uncertainty. Nevertheless, for individual sub-regions and performance metrics observational uncertainty can dominate. This is especially true for precipitation and for metrics targeting the wet-day frequency, the pattern correlation and the distributional similarity. In some cases the spatially averaged mean bias can also be considerably affected. An illustrative ranking exercise highlights the overall effect of observational uncertainty on RCM ranking. Over individual sub-domains, the choice of a specific reference can modify RCM ranks by up to four levels (out of five RCMs). For most cases, however, RCM ranks are stable irrespective of the reference. These results provide a twofold picture: model uncertainty dominates for most regions and for most performance metrics considered, and observational uncertainty plays a minor role. For individual cases, however, observational uncertainty can be pronounced and needs to be definitely taken into account. Results can, to some extent, also depend on the treatment of precipitation undercatch in the observational reference.The present work has been carried out as part of the EU-COST Action VALUE (Validating and Integrating Downscaling Methods for Climate Change Research; ES1102). The authors gratefully acknowledge the providers of RCM and observational data. For the high-resolution national/regional grids these are the University of Cantabria (SP), the Institute of Meteorology and Water Management – National Research Institute (PO), Météo-France/CERFACS (FR), The Swedish Meteorological and Hydrological Institute (SE), Deutscher Wetterdienst (GE), the Hungarian Meteorological Service (CA), the Norwegian Meteorological Institute (NO) and Federal Office of Meteorology and Climatology MeteoSwiss (CH). Furthermore, we acknowledge the E-OBS dataset from the EU-FP6 project ENSEMBLES (http://ensembles-eu.metoffice.com) and the data providers in the ECA&D project (http://eca.knmi.nl). The MESAN data set was provided by the Swedish Meteorological and Hydrological Institute. All analysis were performed on the computing infrastructure of the Swiss National Supercomputing Centre CSCS. They furthermore thank the climate modelling groups of the EURO-CORDEX initiative for producing and making available their model output. The contribution of Olle Räty was partly funded by the Vilho, Yrjö and Kalle Väisälä Foundation of the Finnish Academy of Science and Letters

Achievement goals in adult learners: evidence from distance education

Background: There is evidence that learners may adopt different kinds of achievement goals: mastery approach, mastery avoidance, performance approach, and performance avoidance. In higher education, this evidence has mainly come from young people who have recently gone straight from secondary education to higher education. However, higher education is increasingly populated by older students, and it has been theorised that the relationship between goals and achievement might be very different for adult learners. Aims: The aim of the present study was to examine whether the relationships between achievement, drop‐out rate, and goal orientation observed for non‐adult populations are mirrored in adult learners. Method: The Achievement Goal Questionnaire (AGQ) was administered to adult learners taking courses by distance learning. Sample: Respondents were 195 men and 586 women between the ages of 19 and 87. Results: The results confirmed the reliability of the 2 × 2 version of the AGQ for this distinctive population. As in previous studies of younger students, mastery‐approach goals were unrelated to attainment, performance‐approach goals tended to facilitate attainment, and performance‐avoidance goals tended to impair attainment. In addition, mastery‐avoidance goals tended to impair students' attainment and also increased the likelihood that they would drop out of their course altogether. Conclusion: The achievement‐goal framework is as appropriate for understanding influences on attainment in adult learners as it is in younger students. Adult learners may be more sensitive to the deleterious effects of adopting mastery‐avoidance achievement goals

Exploratory Data Analysis

In the Food research and production field, system complexity is increasing and several new challenges are emerging every day. This implies a urgent necessity to extract information and obtain models capable of inferring the underlying relationships that link all the variability sources which characterize food or its production process (e.g. compositional profile, processing conditions) to very general end-properties of foodstuff, such as the healthiness, the consumer perception, the link to a territory and the effect of the production chain itself on food. This makes a \u201cdeductive\u201d, theory-driven research approach inefficient, since it is often difficult to formulate hypotheses. Explorative Multivariate Data Analysis methods, together with the most recent analytical instrumentation, offer the possibility to come back to an \u201cinductive\u201d data-driven attitude with a minimum of a priori hypotheses, instead helping in formulating new ones from the direct observation of data. The aim of this Chapter is to offer the reader an overview of the most significant tools which can be used in a preliminary, exploratory phase, ranging from the most classical descriptive statistics methods, to Multivariate Analysis methods, with particular attention to Projection methods. For all techniques, examples are given so that the main advantage of this techniques, that is a direct, graphical representation of data and their characteristics, can be immediately experienced by the reader