Descriptive statistics

描述性统计
  • 文章类型: Journal Article
    单案例实验设计(SCED)在教育、心理学,医学,和康复。尽管SCED是确定循证实践的有效实验设计,他们在数据分析中遇到了一些挑战。这些挑战之一,缺少数据,由于随着时间的推移重复测量,在SCED研究中可能经常发生。由于数据缺失是削弱研究有效性和普遍性的关键因素,确定SCED中缺失数据的特征很重要,特别是与少数参与者进行的。在这方面,本研究旨在详细描述SCED研究中缺失的数据特征.为了实现这个目标,调查包括了最近5年内在6种期刊上发表的465项SCED研究。总体结果表明,SCED文章中至少有一个阶段的数据缺失率,作为至少一个数据点,约为30%。此外,结果表明,在发生数据缺失的大多数研究中,数据缺失率超过10%.尽管缺失数据在SCED研究中很常见,只有少数研究(5%)处理了缺失的数据;然而,他们的方法是传统的。在分析SCED数据时,在文献中,考虑到缺失数据率,提出了几种方法。因此,本研究结果中确定的数据缺失率可以通过提高研究结果的有效性和普适性,为采用适当方法分析SCED数据提供依据.
    Single-case experimental designs (SCEDs) have grown in popularity in the fields such as education, psychology, medicine, and rehabilitation. Although SCEDs are valid experimental designs for determining evidence-based practices, they encounter some challenges in analyses of data. One of these challenges, missing data, is likely to be occurred frequently in SCEDs research due to repeated measurements over time. Since missing data is a critical factor that can weaken the validity and generalizability of a study, it is important to determine the characteristics of missing data in SCEDs, which are especially conducted with a small number of participants. In this regard, this study aimed to describe missing data features in SCEDs studies in detail. To accomplish this goal, 465 published SCEDs studies within the recent 5 years in six journals were included in the investigation. The overall results showed that the prevalence of missing data among SCEDs articles in at least one phase, as at least one data point, was approximately 30%. In addition, the results indicated that the missing data rates were above 10% within most studies where missing data occurred. Although missing data is so common in SCEDs research, only a handful of studies (5%) have handled missing data; however, their methods are traditional. In analyzing SCEDs data, several methods are proposed considering missing data ratios in the literature. Therefore, missing data rates determined in this study results can shed light on the analyses of SCEDs data with proper methods by improving the validity and generalizability of study results.
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  • 文章类型: Journal Article
    该研究表明,统计方法如何提供有关控制废弃尾矿库表面元素地球化学分布的因素和过程的信息。在这方面,进行了FunduMoldovei矿石加工厂产生的废物矿床的案例研究。该设施正在浓缩铜,Pb,和锌来自FunduMoldovei-LeSiluUrsului矿区(罗马尼亚)的多金属硫化物矿石。统计数据表明有三种类型的废物,显示特定属性:(i)海滩的浪费,富含可溶性部分(14.4%)和次生矿物质(例如,jarosite,亚铁磷灰石,硅云母,钾盐,和粘土矿物)。后者与相关的高Al含量,K,Fe,Co,Ni,Cu,Pb,和Zn受水分蒸发和随后作为水坑积累的渗滤液的瞬时pH(2.6-3.5)控制。较低的pH和稀缺的可溶性部分有利于铜和锌含量的上升,而Al,K,Fe,当可溶性部分丰富时,在较高的pH值下,Co和Co是明显的。(ii)上坝坡的废物,以强烈的氧化和从高酸性孔隙浸出液中沉淀的次生矿物质微薄的出现(平均pH值为2.55)为标志,即,jarosite,亚铁磷灰石,硅云母,还有Coquimbite.表面废物含有更多的黄铁矿,并且由于降雨过程中会去除细颗粒而变得更粗糙。与海滩垃圾不同,在上坝尾矿中,Al,K,Fe,Co,Cu,Pb,锌似乎主要与主要矿物(白云母,绿泥石,和黄铁矿)。(iii)下坡大坝废物的酸性(平均pH值为3.75)低于上坡;它包含在较高pH下稳定的次生矿物质(例如,石膏,apjohnite,Dietrichite,粘土矿物,和schwertmannite)。钙,Mn,大坝垃圾中Cd含量更高。它们来自初级和次级矿物(例如,白云母,绿泥石,石膏,亚铁磷灰石,和硅铁矿),并与较粗的废物相关。
    The study shows how the statistical approach can provide information on the factors and processes that control the geochemical distribution of elements at the surface of an abandoned tailings pond. In this regard, the case study of a waste deposit resulting from the ore processing plant of Fundu Moldovei was carried out. The facility was concentrating Cu, Pb, and Zn from the polymetallic sulfide ores of the Fundu Moldovei-Leșu Ursului mining district (Romania). The statistics indicate three types of waste, showing specific properties: (i) Waste of the beach, rich in soluble fraction (14.4%) and secondary minerals (e.g., jarosite, ferricopiapite, magnesiocopiapite, pickeringite, and clay minerals). The latter and the related high contents of Al, K, Fe, Co, Ni, Cu, Pb, and Zn are controlled by the water evaporation and subsequent transient pH (2.6-3.5) of the leachates accumulated as puddles. The lower pH and scarce soluble fraction favor a rise in the Cu and Zn contents, while Al, K, Fe, and Co are noticeable at a higher pH when the soluble fraction is abundant. (ii) Waste of the upper dam slope, marked by intense oxidation and a meager occurrence of secondary minerals precipitated from highly acidic pore leachates (average pH of 2.55), namely, jarosite, ferricopiapite, magnesiocopiapite, and coquimbite. The surface waste contains more pyrite and is coarser because of the fine particle removal during rainfall. Unlike the beach waste, in the upper dam tailings, Al, K, Fe, Co, Cu, Pb, and Zn seem to relate mainly to the primary minerals (muscovite, chlorite, and pyrite). (iii) Downslope dam waste is less acidic (average pH of 3.75) than that of the upper slope; it contains secondary minerals stable at a higher pH (e.g., gypsum, apjohnite, dietrichite, clay minerals, and schwertmannite). Calcium, Mn, and Cd are more abundant in the dam waste. They originate from both primary and secondary minerals (e.g., muscovite, chlorite, gypsum, ferricopiapite, and magnesiocopiapite) and correlate with the coarser waste.
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  • 文章类型: Journal Article
    The appropriate acquisition and processing of water quality data are crucial for water resource management. As such, published articles on water quality monitoring and assessment are meant to convey essential and reliable information to water quality experts, decision-makers, researchers, students, and the public. The implication is that such information must emanate from data obtained and analysed in an up-to-date, scientifically sound manner. Thus, inappropriate data analysis and reporting techniques could yield misleading results and mar the endeavours of achieving error-free conclusions. This study utilises the findings on water quality assessment in Nigeria over the last 20 years to reveal the likely trends in water quality research regarding data collection, data analysis, and reporting for physicochemical, bacteriological parameters, and trace organics. A total of 123 Web of Science and quartile ranked (Q1-Q4) published articles involving water quality assessment in Nigeria were analysed. Results indicated shortcomings in various aspects of data analysis and reporting. Consequently, we use simulated heatmaps and graphs to illustrate preferred ways of analysing, reporting, and visualising some regularly used descriptive and inferential statistics of water quality variables. Finally, we highlight alternative approaches to the customarily applied water quality assessment methods in Nigeria and emphasise other areas of deficiency that need attention for improved water quality research.
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  • 文章类型: Case Reports
    With the conventional 2D exam of clinical cases, the diagnosis is penalized by the lack of data, not only for vertical or transverse or asymmetrical problems, but for classical cases of anteroposterior dysharmonies. In these cases, the effectively used parameter, ANB angle, seems insufficient. So the authors elaborated a 3D biometry tool. The program of morphological analysis is able to deliver a complete description of dysharmony, supported by Cone Beam data capture. In the first part of this article the authors present the foundation of the model: anatomical reference, skeletal landmarks, teeth location by inertia matrix calculus, parameters, diagnosis and aid to treatment plan. The second part is the presentation, step by step, of the program in function, analyzing a great case of Class II hyperdivergent, border line surgery. All along the diagnosis way, the authors make the assistant discover all the documents given by the computer about complete 3D diagnosis and aid to treatment plan.
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