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Inferential Statistics (inferential + statistics)
Selected AbstractsMulti-scale sampling and statistical linear estimators to assess land use status and changeAPPLIED VEGETATION SCIENCE, Issue 2 2009D. Rocchini Abstract Question: Multi-temporal analysis of remotely sensed imagery has proven to be a powerful tool for assessment and monitoring of landscape diversity. Here the feasibility of assessing land-use diversity and land-use change was tested at multiple scales and over time by means of statistical linear estimators based on a probabilistic sampling design. Location: The study area (the district of Asciano, Tuscany, Italy) is characterized by erosional forms typical of Pliocene claystone (i.e. calanchi and biancane) that have been subject to the phenomenon of biancane reworking over the past 50 years, mainly owing to the expansion of intensive agriculture. Methods: Cells at two different scales (50 m × 50 m and 10 m × 10 m) were classified by two operators according to a multilevel legend, using 1954 and 2000 aerial photographs. Inter-operator agreement and accuracy were tested by Cohen's K coefficient. Total land cover estimation for each class was carried out using a multistage estimator, while the variance was estimated by means of the Wolter estimator. Field-based information on plant species composition was recorded in order to test for a relationship between land use and plant community composition by anova and indicator species analysis. Results: Agreement between photointerpreters and accuracy were significantly higher than those expected by chance, proving that the approach proposed is reproducible, as long as proper quality assurance methods are used. Our data show that, at the two scales considered (50 m × 50 m and 10 m × 10 m), crops have increased against woodlands and semi-natural areas, the latter showing the highest and significantly different mean species richness. Meanwhile, an increase in the coverage of trees and shrubs was found within the semi-natural areas, probably as a result of secondary succession occurring on typical landscape elements such as biancane. Conclusions: Inferential statistics made it possible to acquire quantitative information on the abundance of land cover classes, allowing formal multi-temporal and multi-scale analysis. Sampling design-based statistical linear estimators were found to be a powerful tool for assessing landscape trends considering both time expenditure and other costs. They make it possible to maintain the same scale of analysis over time series data and to detect both coarse- and fine-grained changes in spatial patterns. [source] Spatial independent component analysis of functional MRI time-series: To what extent do results depend on the algorithm used?HUMAN BRAIN MAPPING, Issue 3 2002Fabrizio Esposito Abstract Independent component analysis (ICA) has been successfully employed to decompose functional MRI (fMRI) time-series into sets of activation maps and associated time-courses. Several ICA algorithms have been proposed in the neural network literature. Applied to fMRI, these algorithms might lead to different spatial or temporal readouts of brain activation. We compared the two ICA algorithms that have been used so far for spatial ICA (sICA) of fMRI time-series: the Infomax (Bell and Sejnowski [1995]: Neural Comput 7:1004,1034) and the Fixed-Point (Hyvärinen [1999]: Adv Neural Inf Proc Syst 10:273,279) algorithms. We evaluated the Infomax- and Fixed Point-based sICA decompositions of simulated motor, and real motor and visual activation fMRI time-series using an ensemble of measures. Log-likelihood (McKeown et al. [1998]: Hum Brain Mapp 6:160,188) was used as a measure of how significantly the estimated independent sources fit the statistical structure of the data; receiver operating characteristics (ROC) and linear correlation analyses were used to evaluate the algorithms' accuracy of estimating the spatial layout and the temporal dynamics of simulated and real activations; cluster sizing calculations and an estimation of a residual gaussian noise term within the components were used to examine the anatomic structure of ICA components and for the assessment of noise reduction capabilities. Whereas both algorithms produced highly accurate results, the Fixed-Point outperformed the Infomax in terms of spatial and temporal accuracy as long as inferential statistics were employed as benchmarks. Conversely, the Infomax sICA was superior in terms of global estimation of the ICA model and noise reduction capabilities. Because of its adaptive nature, the Infomax approach appears to be better suited to investigate activation phenomena that are not predictable or adequately modelled by inferential techniques. Hum. Brain Mapping 16:146,157, 2002. © 2002 Wiley-Liss, Inc. [source] Correlates of apparel significance among older men and womenINTERNATIONAL JOURNAL OF CONSUMER STUDIES, Issue 3 2000Usha Chowdhary Abstract A total of 978 older men and women (over 65 years) were systematically identified from a list of registered voters and asked to participate in a study examining the correlates of apparel significance (extent to which apparel is considered important by an individual). A postal survey technique was used to collect the data. Both descriptive and inferential statistics were used to analyse and interpret the data. The condition number index was used to test for multicollinearity of data. Pearson product moment correlation coefficients, analysis of variance and stepwise multiple regression were used to analyse the data. The findings revealed that apparel significance was positively related to self-esteem, age perception, media usage, opinion leadership and social participation. Stepwise multiple regression results indicated that 65·3% of the variance was explained by media usage, opinion leadership and sex. [source] Assessment of patient satisfaction with pharmaceutical services in a Nigerian teaching hospitalINTERNATIONAL JOURNAL OF PHARMACY PRACTICE, Issue 1 2004Azuka C. Oparah lecturer ABSTRACT Objective To assess patients' satisfaction with pharmaceutical services using an"ideal referent" model, and to further explore the validity of an existing patient satisfaction instrument. Method A cross-sectional survey was conducted with a sample of 500 outpatients recruited consecutively at the University of Benin teaching hospital, Nigeria. A self-completion questionnaire that employed a Likert-type scale was used. Data were used to calculate scores on a scale that ranged from 20 to 100, with an assumed midpoint of 60. Descriptive statistics on the sample characteristics and questionnaire items were computed including means, standard deviations and frequency distributions. Varimax rotation with Kaiser normalisation was employed in principal factor analysis. Student's t -test and one-way ANOVA were used for inferential statistics. Key findings The instrument reliability was determined to be 0.9641 and was comparable to the reference study. Nearly half of the patients (46%) rated the amount of time the pharmacist offered to spend with them as poor. About one-third rated promptness of prescription service as poor. Only 49% felt satisfied with the pharmaceutical services. Overall, pharmacy services received a satisfaction rating of 56.04±24.49, below the midpoint. Perceived satisfaction was significantly higher in "friendly explanation" than in "managing therapy" (t=3.916; P<0.0001). Conclusion The study provides evidence that patients experience low satisfaction with current pharmaceutical services at the study hospital. The sociodemographic characteristics of patients were not associated with their level of satisfaction. We further confirm the validity of the patient satisfaction questionnaire in a Nigerian practice setting. [source] Critical thinking and learning styles of students in conventional and accelerated programmesINTERNATIONAL NURSING REVIEW, Issue 1 2006W. A. Suliman rn Aim and purpose:, To assess the difference between the predominant critical thinking disposition(s) and learning styles of nursing students in the conventional (Stream I) and the accelerated (Stream II) baccalaureate nursing education programmes. This study will be beneficial to students, faculty and institutions as it will help them to acquire better understanding of critical thinking potentials and learning styles of nurses, as well as the relationship between learning styles and critical thinking dispositions. Method:, This was a descriptive correlational study. The convenience sample consisted of 80 Stream I and 50 Stream II students. The following instruments were used for data collection: The Learning Styles Inventory of Kolb and the California Critical Thinking Dispositions Inventory of Facione and Facione. Descriptive and inferential statistics were used to analyse the data. Results:, Overall, Stream II students were significantly more critical thinkers (P = 0.000), inquisitive (P = 0.000) and self-confident (P = 0.002). The predominant learning styles of Streams I and II were the diverger and the converger, respectively, with no difference except in relation to their learning abilities, namely, concrete experience (P = 0.017), in favour of Stream I. Further, the findings indicate a weak (range of r = 0.209,0.328) though significant (range of P = 0.017,0.000) correlation between learning abilities and various critical thinking dispositions. [source] Nurses' perceptions of individualized careJOURNAL OF ADVANCED NURSING, Issue 5 2010Riitta Suhonen suhonen r., gustafsson m.-l., katajisto j., välimäki m. & leino-kilpi h. (2010) Nurses' perceptions of individualized care. Journal of Advanced Nursing,66(5), 1035,1046. Abstract Title.,Nurses' perceptions of individualized care. Aim., This paper is a report of a study of nurses' perceptions of individualized care, the factors associated with these perceptions, and nurses' perceptions of the provision of individualized care in different types of healthcare organization. Background., Although individualized care has been an internationally-challenging and long-standing research topic in nursing, the current literature on individualized care from the perspective of nurses is limited. Methods., A cross-sectional, descriptive and exploratory design using a questionnaire (Individualised Care Scale,Nurse) was employed to survey a stratified sample of 544 nurses (response rate 59%) working as Registered or Enrolled Nurses in one hospital district in Finland in 2008. Data were analysed using descriptive and inferential statistics (General Linear Model, one-way analysis of variance) and Cronbach's alpha coefficients for reliability analysis. Results., Nurses perceived that they supported patient individuality well and that the care they provided took into account patient individuality. Based on the General Linear Model, nurses' background variables were not associated with their perceptions of individualized care delivery. However, between-organization differences were found in all study variables: mental health ward nurses had the most positive perceptions, and nurses working in primary health centre long-term care wards the lowest. Conclusion., Healthcare organizations and work environments need to be evaluated as they may have an influence on individualized care provision. The Individualised Care Nurse instrument is sensitive to healthcare working environments and can be used in evaluating nurses' perceptions of individualized care. [source] Comparing Norwegian nurses' and physicians' perceptions of the needs of significant others in Intensive Care UnitsJOURNAL OF CLINICAL NURSING, Issue 5 2005Christina Takman CCRN Aim and objectives., To illuminate and compare the perceptions of registered nurses (n = 243) and physicians (n = 29) in medical and surgical ICUs for adults on the needs of significant others. Background., Previous studies have established the necessity for healthcare professionals in Intensive Care Units (ICUs) to identify and meet the needs of critically ill adult patients' significant others. Design., A survey was conducted and data from the Critical Care Family Needs Inventory were analysed using descriptive and inferential statistics. Results., The findings revealed four factors: ,attentiveness and assurance', ,taking care of themselves', ,involvement', and ,information and predictability'. Nurses scored higher than physicians on ,attentiveness and assurance'. Nurses with experience of being a patient or a significant other in an ICU placed a higher value on ,involvement' compared with nurses without such experience, while physicians with such experience scored higher on ,information and predictability' compared with those without such experience. Older physicians and those with extensive professional and ICU experience had a low score on ,involvement', but scored higher on ,information and predictability' compared with physicians with less experience. Nurses with extensive ICU and professional experience also scored higher on ,information and predictability' than nurses with less experience. Women placed a higher value on each of the four factors than men. Conclusion., The study revealed variations in ICU professionals' perceptions of significant others' needs. Relevance to clinical practice., There is a need for nurses and physicians to acknowledge that varying perceptions on significant others needs could lead to different ways of conducting themselves in encounters with significant others in ICUs. There is also a risk that the patients' significant others could be forced to adapt themselves to professionals' different and perhaps contradictory perceptions of their needs in ICUs. [source] Caterers' experiences and perceptions of implementing the 2006 school meal standardsJOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 5 2008C.J. Weir Background:, School meal standards were introduced in 2006 (Department for Education and Skills) and caterers are expected to comply with these standards. No research has been conducted looking at the caterer's experiences and perceptions of implementing these standards. This area has 32 school meal provider organisations for 103 schools. Half the schools are with one provider and the others are, mostly, single-handed in-house operations, often managed by a local community member. The aim of the current study was to explore caterers' understanding of the school meal standards, the barriers to implementation, and proposed solutions, to inform local practice. Methods:, A combined quantitative and qualitative design was used. A questionnaire was used to assess understanding and implementation of the standards and distributed to all the catering provider organisations (n = 32), with a good response rate of 78% (n = 25). For each question about achievement of the ten food-based standards the responses were scored 0,4 where: 0 = ,Do not intend to achieve this standard'; to 4 = ,Fully achieved'. This gave a total standards achievement score for each catering provider organisation, where the minimum score that could be achieved was zero which indicated the minimum level of achievement and the maximum score which could be achieved was forty which indicated all ten standards fully achieved. Four focus group were undertaken involving 40 people who considered themselves to be in a management role within a catering provider organisation. Semi structured interviews were undertaken with 11 people (until saturation), using purposive sampling, to explore barriers and solutions to implementation of the standards in detail. Descriptive and appropriate inferential statistics (Fisher's Exact tests and independent samples t- tests) were performedon the datausingStatistical Package for Social Sciences (SPSS). The process undertaken for the qualitative analysis was thematic analysis, and used analytic hierarchy (Richie & Lewis, 2003). Approval for this study was obtained from Leeds Metropolitan University ethics committee. Results:, The qualitative discussions led to caterers' identifying two main themes. These were: support from various groups, and the roles and responsibilities caterers believed these groups had and should be performing in order to achieve successful implementation of the standards ,Think it's good someone's shaken up school meals but who is doing the actually work , it's us isn't it'.(Semi structured interview respondent medium primary provider) ,I've found it really difficult as I'm on my own at the school, totally on my own without anyone to help'. (Focus group participant primary school group). The groups that caterers identified as those who had roles and responsibilities and who should be providing support were the ,whole school'; catering provider organisations; parents; the local authority; and, the broader environment/whole population. Caterers felt the standards had ,gone too far too soon' and did not allow choice. Caterers felt finances were a barrier, and that training was required across all sectors to achieve success. The standards implementation achievement score were statistically higher for caterers who had received formal training compared with those with only food and hygiene (P = 0.001); and, between caterers who provided to a secondary school as opposed to a primary school only (P = 0.034). There was a statistically significant relationship between providers and qualifications with those providing to secondary schools more likely to have had formal qualifications (P = 0.015). Discussion:, Caterers felt all those involved in schools and school meals needed to undertake their roles and responsibilities, to provide support, and, to implement the ethos of a whole school approach. The caterers in this study identified many barriers and practical obstacles either experienced or perceived to implementing the new school meals standards. Conclusions:, The results will be used to inform the Local Authority and Primary Care Trust to ensure the effective implementation of the school meal standards. There may be opportunity to transfer these results to other school caterers, and to develop support and training to assist implementation. [source] Residential Design Implications of Consumers' Recycling BehaviorsJOURNAL OF INTERIOR DESIGN, Issue 1-2 2003Sharon Macy M.A. ABSTRACT Each year landfills receive a growing amount of waste that could be eliminated by recycling practices supported through the design of kitchens. This study had three objectives: (a) to examine residential design implications for incorporating recycling within the home, (b) to examine consumer's feelings of environmental altruism and their behaviors toward recycling within the context of situational conditions within the home, and (c) to examine consumer's views regarding the convenience of their home's recycling facilities. The primary research instrument was a survey of consumer behaviors and attitudes toward recycling. Certified Kitchen Designers provided client names for whom they had designed a kitchen as part of a remodel or new home construction within the last five years. Questionnaires were mailed to 271 households with a 58.2% response rate achieved. Five areas of information were addressed in the survey: sociode-mographics, behaviors and situational design factors, altruistic values, perceived inconvenience, and economic factors. Descriptive and inferential statistics were used for analysis with Chi-square tests used to examine relationships between variables. Results support including an area for recycling in the kitchen or a space that is directly adjacent such as an attached garage; convenience was found to be a primary factor in the recycling behaviors of highly altruistic individuals. It is important to design an environment that supports recycling. Whether recycling is convenient or not will have an influence on an individual's recycling behaviors. With environments that support recycling behaviors, consumers will increase their quantity and accuracy in recycling, which in turn could lead to an increase in attitudes toward other pro-environmental actions. [source] Rate, causes and reporting of medication errors in Jordan: nurses' perspectivesJOURNAL OF NURSING MANAGEMENT, Issue 6 2007MAJD T. MRAYYAN PhD Aim, The aim of the study was to describe Jordanian nurses' perceptions about various issues related to medication errors. Background, This is the first nursing study about medication errors in Jordan. Methods, This was a descriptive study. A convenient sample of 799 nurses from 24 hospitals was obtained. Descriptive and inferential statistics were used for data analysis. Results, Over the course of their nursing career, the average number of recalled committed medication errors per nurse was 2.2. Using incident reports, the rate of medication errors reported to nurse managers was 42.1%. Medication errors occurred mainly when medication labels/packaging were of poor quality or damaged. Nurses failed to report medication errors because they were afraid that they might be subjected to disciplinary actions or even lose their jobs. In the stepwise regression model, gender was the only predictor of medication errors in Jordan. Conclusions, Strategies to reduce or eliminate medication errors are required. [source] Bone mineral density among cirrhotic patients awaiting liver transplantationLIVER TRANSPLANTATION, Issue 5 2004Rana Paramvir Sokhi Osteoporosis is an important and common complication in patients with chronic liver disease. The goal of this study was to determine the bone mineral density (BMD) in different subgroups among pretransplant cirrhotic patients. BMD of the lumbar vertebrae (L) and femoral neck (F) were obtained in 104 consecutive cirrhotic patients. Descriptive and inferential statistics were used to compare the BMD among various groups. The mean BMD in males (n = 54) and females (n = 50) at L were 1.28 ± 0.25 g/cm2 and 1.13 ± 0.20 g/cm2, respectively (P = .001); at F they were 1.03 ± 0.14 and 0.91 ± 0.17, respectively (P < .0001). Among males, BMD at L in Child-Turcotte-Pugh class B and C were 1.40 ± 0.21 and 1.13 ± 0.20, respectively (P = .001); at F they were 1.11 ± 0.10 and 0.93 ± 0.13, respectively (P < .0001). Among females, BMD at L in Child-Turcotte-Pugh class B and C were 1.27 ± 0.18 and 1.05 ± 0.16, respectively (P = .0003); at F they were 1.02 ± 0.16 and 0.83 ± 0.12, respectively (P = .001). The BMD in premenopausal females (n = 15) and postmenopausal females (n = 35) at L were 1.20 ± 0.19 and 1.11 ± 0.20, respectively (P = .15); at F they were 0.97 ± 0.17 and 0.88 ± 0.16, respectively (P = .12). The BMD in postmenopausal females on hormone replacement therapy (n = 19) and on no hormone replacement therapy (n = 16) at L were 1.07 ± 0.17 and 1.14 ± 0.23, respectively (P = .29); at F they were 0.85 ± 0.15 and 0.91 ± 0.18, respectively (P = .33). The BMD values between etiologic groups were not significantly different. The overall prevalence of osteopenia and osteoporosis were 34.6% and 11.5%, respectively, being significantly higher in females than in males. In conclusion, significant difference in BMD values exists between males and females, as well as between Child-Turcotte-Pugh class B and C patients with cirrhosis. In addition, there is no significant influence of menopausal status, hormone replacement therapy, and etiology of cirrhosis on BMD. (Liver Transpl 2004;10:648,653.) [source] An introduction to medical statistics for health care professionals: Hypothesis tests and estimationMUSCULOSKELETAL CARE, Issue 2 2005Elaine Thomas PhD MSc BSc Lecturer in Biostatistics Abstract This article is the second in a series of three that will give health care professionals (HCPs) a sound introduction to medical statistics (Thomas, 2004). The objective of research is to find out about the population at large. However, it is generally not possible to study the whole of the population and research questions are addressed in an appropriate study sample. The next crucial step is then to use the information from the sample of individuals to make statements about the wider population of like individuals. This procedure of drawing conclusions about the population, based on study data, is known as inferential statistics. The findings from the study give us the best estimate of what is true for the relevant population, given the sample is representative of the population. It is important to consider how accurate this best estimate is, based on a single sample, when compared to the unknown population figure. Any difference between the observed sample result and the population characteristic is termed the sampling error. This article will cover the two main forms of statistical inference (hypothesis tests and estimation) along with issues that need to be addressed when considering the implications of the study results. Copyright © 2005 Whurr Publishers Ltd. [source] Emotional intelligence, reactions and thoughts: Part 2: A pilot studyNURSING & HEALTH SCIENCES, Issue 3 2009Kristin Akerjordet int, mnsc Abstract This article, the second in a series of four, focuses on new mothers' perceptions of emotional intelligence, reactions and thoughts by means of a descriptive design. The study included 250 postnatal mothers (a response rate of 80%). The data were analyzed using descriptive and inferential statistics. The results show that, from a health promotion perspective, emotional intelligence might be an important component in relation to stress management and mental health. However, emotionally perceptive women seem to be affected by stress and depression to a greater extent. The relative strength of the associations between the scales also provides a valid and useful overall measure of new mothers' perceptions. Further validity scores for the scales must be obtained before any conclusions can be drawn. [source] Logic of experiments in ecology: is pseudoreplication a pseudoissue?OIKOS, Issue 1 2001Lauri Oksanen Hurlbert divides experimental ecologist into ,those who do not see any need for dispersion (of replicated treatments and controls), and those who do recognize its importance and take whatever measures are necessary to achieve a good dose of it'. Experimental ecologists could also be divided into those who do not see any problems with sacrificing spatial and temporal scales in order to obtain replication, and those who understand that appropriate scale must always have priority over replication. If an experiment is conducted in a spatial or temporal scale, where the predictions of contesting hypotheses are convergent or ambiguous, no amount of technical impeccability can make the work instructive. Conversely, replication can always be obtained afterwards, by conducting more experiments with basically similar design in different areas and by using meta-analysis. This approach even reduces the sampling bias obtained if resources are allocated to a small number of well-replicated experiments. For a strict advocate of the hypothetico-deductive method, replication is unnecessary even as a matter of principle, unless the predicted response is so weak that random background noise is a plausible excuse for a discrepancy between predictions and results. By definition, a prediction is an ,all-statement', referring to all systems within a well-defined category. What applies to all must apply to any. Hence, choosing two systems and assigning them randomly to a treatment and a control is normally an adequate design for a deductive experiment. The strength of such experiments depends on the firmness of the predictions and their a priori probability of corroboration. Replication is but one of many ways of reducing this probability. Whether the experiment is replicated or not, inferential statistics should always be used, to enable the reader to judge how well the apparent patterns in samples reflect real patterns in statistical populations. The concept ,pseudoreplication' amounts to entirely unwarranted stigmatization of a reasonable way to test predictions referring to large-scale systems. [source] Gradients of occlusal wear in hunter-gatherers and agriculturalistsAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009Christina A. Deter Abstract Occlusal wear was recorded in maxillary teeth from three North American late Archaic (3385 ± 365 cal BC) hunter-gatherer sites (n = 306) and late Anasazi-early Zuni agricultural sites (,1300 AD) (n = 87). Comparisons were undertaken using descriptive and inferential statistics to determine differences between these groups, and along the maxillary tooth row. The hunter-gatherers had a significantly greater percentage of occlusal wear than the agriculturalists. For both hunter-gatherers and agriculturalists, occlusal wear was greatest on the central incisors and first molars. The third molars had the least amount of wear. It was inferred from these results that the hunter-gatherers had a more abrasive diet, and different daily task activities compared to the agriculturalists. One further finding was that wear patterns on anterior and posterior teeth are influenced by the order that teeth erupt into the jaw, as well as diet and behavior. 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