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1.
分别基于因素分析法和逐步回归法,按照因子载荷和对误差解释率的大小,依次组成包含3、4、5、6个题型的简版测验.计算每种简版测验与全版测验的相关大小,以及在给定误差的情况下,每种简版测验的覆盖率.分别比较在给定及格分数线60和70分时,每种简版测验的总命中率和正命中率.结果为:1)基于因素分析方法开发的4种简版测验与全版测验的相关均达到显著水平,但重复测量的方差分析表明,这些简版测验与完整版测验分数的差异达到显著水平;2)基于逐步回归方法开发的4种简版测验与全版测验的相关均达到显著水平,但重复测量的方差分析表明,包含3和4个分测验的简版测验分数与全版测验的分数差异并不显著;3)当将60分作为及格线时,基于回归分析方法开发的简版测验的总命中率高于相应的基于因素分析方法开发的简版测验的总命中率,但正命中率却低于相应的简版测验.当将70分作为及格线时,基于回归分析方法开发的简版测验的总命中率高于相应的基于因素分析方法开发的简版测验的总命中率,但正命中率却没有表现出类似趋势.总体上讲,基于回归分析方法开发的简版测验与全版的相关,覆盖率以及命中率优于基于因素分析方法开发的简版测验.  相似文献   

2.
在连续施测下计算机自适应测验(CAT)中的试题被曝光的可能性急剧增加,因此需要对试题进行实时监控,当试题的参数发生显著性变化时必须将其进行强制“退休”.序贯监测程序(SMP)通过检测CAT中的试题统计特征的变化来判断试题是否泄露; 然而在用SMP监控试题时会出现较大的Ⅰ类错误率,并且在一些条件下其统计检验力较低.该文以残差的R指标作为考生拟合统计量(PFS),与SMP方法相结合,构建了一种新的监测方法(PFS_SMP); 该方法以被试作答信息为依据判断被SMP标记的试题是否泄露,从试题和被试这2个层面保证测验的安全性和公平性.最后,通过模拟实验和实证分析来对基于R的PFS_SMP的表现进行评价,实验结果表明:PFS_SMP方法能降低在SMP监测试题时的Ⅰ类错误,并能提高其统计检验力.  相似文献   

3.
测验等值的单组设计,是将需等值的测验X、Y都由同一考生组施测,然后对测验分数进行等值。其优点是考生组织只有一个,X、Y成绩的差异交归因于测验的不同而不会混杂先生性组不同的因素。缺点是同一考生要测验两次,练习效应和疲劳将会干扰结果。本文提出一种新的设计方法--单组设计试卷分半法,是在单组设计中,把测验X、Y各分成平行的两半卷分半法各取X、Y的半卷组成新的测验Z,将Z对同一考生组施测,根据施测结果导出  相似文献   

4.
选用情境差异范式,以情景判断测验为实验材料,以140名大学生为被试,探讨警告以及标准识别能力对考生作假的影响.结果表明,情景判断测验中存在作假现象.标准识别能力显著正向预测作假.警告与标准识别能力的交互作用可预测作假,对于标准识别能力较高的考生,警告不但不能减少作假,反而助长作假;对于标准识别能力较低的考生,警告无明显作用.  相似文献   

5.
在统计检验中,会犯两种类型的错误第一类错误与第二类错误.以单个均值的检验为例,分析了它们的成因和计算方法.可以认为,第一类错误由检验中的实际推断原理引起,第二类错误由检验中的逻辑谬误引起.第一类错误出现的概率为显著性水平α,即小概率事件发生的概率.第二类错误的计算方法是阐述的重点,也是在解决这一问题上与目前的方法不一致的地方.  相似文献   

6.
CSIBTEST方法是基于参照组和目标组2个测验信度对真分数进行估计,再按交叉位置分数将匹配分数划分为2类子样本,并分别计算其卡方统计量,然后将这2个独立的卡方统计量相加得到自由度为2的检验统计量.鉴于测验信度具有群体依赖性,即不同群体的测验信度可能不尽相同,而CSIBTEST方法将参照组和目标组分别划分为2类子样本,有必要对子样本上的测验信度也进行估计,由此拓展了CSIBTEST.新方法先使用CSIBTEST获得交叉位置参数,相当于进行DIF预分析,再使用子样本上的信度估计用于真分数估计,以在对匹配变量进行纯化后获得检测统计量.模拟研究结果显示:相比SIBTEST和CSIBTEST,匹配变量纯化的测验偏差检验方法对存在DIF试题有着更高的统计检验力.  相似文献   

7.
正交设计是安排多因子试验的一种高效的试验设计方法,方差分析是对因子进行显著性检验的常用方法.众所周知,F检验对方差齐性的偏离较为敏感,当混水平正交试验不同处理组合下误差方差不相等时,基于F检验的方差分析将会导致错误结论.为此,本文提出新的检验统计量,并通过随机模拟的方法获得相应的临界值,分别利用F检验与新检验方法对各因子进行显著性检验,模拟结果表明在试验误差方差不等时新的检验方法控制犯第一类错误的概率更精确,因子的显著性检验更可靠.  相似文献   

8.
宫凌 《科技信息》2013,(9):246-246
<正>0引言SAT是英文Scholastic Assessment Test的缩写,中文名称为学术能力评估考试,是由总部位于美国新泽西州普林斯顿市的美国教育考试服务中心(Educational Testing Service,简称ETS)举办的。Sat考试即是:美国高考。SAT考试主要测验考生的写作、阅读和数学能力,每部分满分是800分,总分是2400分;SAT考试时间三小时四十五分钟,题型为选择题及写作,主要测验考生的阅读、数学及写作能力,满分是2400分。  相似文献   

9.
本文应用教育统计、教育测量与多种数学方法,系统研究了大规模统考中,考试信息的充分利用和在 Apple—Ⅱ微机上的处理方案,建立了“考试信息系统工程”。“工程”依据命题计划,考生获分与考生情况,对试题质量作项目分析,寻求影响成绩原因,预测考生成绩,对考生、班级作出学习与教学诊断,评估教学的效果,排列评估名次,还可用于学藉管理与择优录取。  相似文献   

10.
为提高他什店站径流量统计成果精度,减小由于流量测次分布不够,而使得流量资料整编时所推算出的径流量存在一定的误差。通过对比分析,选择一种既降低单次测流的工作量并缩短测流时间、同时所测流量的测验误差符合规范规定的流速仪流量测验方法,用这种方法增加每日流量测验的次数,尽可能达到能反映流量日变化的过程,提高用连实测流量过程线法进行流量资料整编的精度,进一步提高径流量统计成果的精度。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

20.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

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