نتایج جستجو برای: simple random sampling was used first

تعداد نتایج: 6053876  

1999
Osamu Watanabe

We explain three random sampling techniques that are simple but widely applicable for various problems involving huge data sets. The first technique is an immediate application of large deviation bounds. The second and the third ones are sequential sampling or adaptive sampling techniques. We fix one simple problem and explain these techniques by demonstrating algorithms for this problem and di...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی - دانشکده علوم تربیتی و روانشناسی 1393

the purpose of this study was to investigate the relationship between teachers’ class management practices with students’ self- regulated learning and academic self-efficacy. in this study relating to the management class, three dimensions, (training management, people management and behavior management) and three style (interventionist, interactionist and non-interventionist) was considered. r...

2010
Tsung-Hau Jen Hak-Ping Tam Margaret Wu

The precision of parameters estimation are determined by the sample size and the sampling design used in a study. Due to such practical constraints as the budget and manpower, most large-scale educational studies would not adopt the simple random sampling design. TIMSS 2007 used a two-stage stratified cluster sampling design. In the first stage, about 150 schools were selected according to some...

2002
Douglas Olson

Stratified random sampling at differential rates is commonly used in social science surveys to improve the chances of getting sufficiently large samples of subpopulations of interest. Multi-phase sampling is often used to further target desired populations. The variances of such samples can be estimated using jackknifing, which creates replicated values of the characteristic of interest as if o...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده زبانهای خارجی 1393

the purpose of this study was to examine the english language needs of medical students at tehran university of medical sciences . analysis of the needs took place for three groups: 320 undergraduate students, 30 postgraduate students and 20 university instructors. a triangulation approach to collect data was used in which a combination of the quantitative (using the questionnaires) and qualita...

2012
F. Azna A. Shahabuddin Kamarulzaman Ibrahim

Many works have been carried out to compare the efficiency of several goodness of fit procedures for identifying whether or not a particular distribution could adequately explain a data set. In this paper a study is conducted to investigate the power of several goodness of fit tests such as Kolmogorov Smirnov (KS), Anderson-Darling(AD), CramervonMises (CV) and a proposed modification of Kolmogo...

2005
Uriel Feige Abraham D. Flaxman Jason D. Hartline Robert D. Kleinberg

We give a simple analysis of the competitive ratio of the random sampling auction from [10]. The random sampling auction was first shown to be worst-case competitive in [9] (with a bound of 7600 on its competitive ratio); our analysis improves the bound to 15. In support of the conjecture that random sampling auction is in fact 4-competitive, we show that on the equal revenue input, where any s...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده زبانهای خارجی 1392

the extent to which written corrective feedback on linguistic errors can play a role in helping l2 writers improve the accuracy of their writing continues to be an issue of interest to researchers and teachers since truscott (1996) mounted a case for its abolition. while there is growing empirical evidence that written corrective feedback can successfully target some types of linguistic error (...

Journal: :Water research 2002
Molly K Leecaster Kenneth Schiff Liesl L Tiefenthaler

Monitoring programs for urban runoff have not been assessed for effectiveness or efficiency in estimating mass emissions. In order to determine appropriate designs for stormwater, total suspended solids (TSS) and flow information from the Santa Ana River was collected nearly every 15 min for every storm of the 1998 water year. All samples were used to calculate the "true load" and then three wi...

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