نتایج جستجو برای: utilizing one sample t

تعداد نتایج: 2921728  

2012
Maryam Amidi Mazaheri

Materials and Methods: This Randomized Control Trial consists of two experimental and control groups. The experimental group received intervention based on Health Action Model. Control group did not receive any intervention except participating in the current safety courses of company. The sample size was 270 worker who were randomly selected and divided into two experimental (n=135) and contro...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی اصفهان - دانشکده ریاضی 1390

the main objective in sampling is to select a sample from a population in order to estimate some unknown population parameter, usually a total or a mean of some interesting variable. a simple way to take a sample of size n is to let all the possible samples have the same probability of being selected. this is called simple random sampling and then all units have the same probability of being ch...

Journal: :Controlled clinical trials 1981
J M Lachin

The importance of sample size evaluation in clinical trials is reviewed and a general method is presented from which specific equations are derived for sample size determination or the analysis of power for a wide variety os statistical procedures. The method is discussed and illustrated in relation to the t test, tests for proportions, tests of survival time, and tests for correlations as they...

Journal: :Psychonomic bulletin & review 2007
Natalie A Obrecht Gretchen B Chapman Rochel Gelman

Normatively, a statistical pairwise comparison is a function of the mean, standard deviation (SD), and sample size of the data. In our experiment, 203 undergraduates compared product pairs and judged their confidence thatone product was better than the other. We experimentally manipulated (within subjects) theaverage productratings, the number of raters (sample size), and the SD of the ratings....

2012
Kyung Do Han Yong Gyu Park

One of the simplest and most widely used multiple comparison tests is the Bonferroni adjustment (test). It is applicable to the following situations: 1) Regardless of whether or not the sample sizes of each group are equal. 2) When the family of interest is the particular set of comparisons (not all pair-wise comparisons). We can easily obtain the results of the Bonferroni comparison by multipl...

2010
A. Wong Junbin B. Gao

In introductory statistics texts, the power of the test of a one-sample mean when the variance is known is widely discussed. However, when the variance is unknown, the power of the Student’s t-test is seldommentioned. In this note, a general methodology for obtaining inference concerning a scalar parameter of interest of any exponential family model is proposed. The method is then applied to th...

1982
Maurice Jones

JONES, SHELTON MAURICE. Improved Variance Estimators Using Weighting Class Adjustments for Sample Survey Nonresponse. (Under the direction of Robert G. D. Steel.) In large-scale sample surveys, there will always be the problem of nonresponse. There are several imputation procedures designed to adjust for nonresponding sampling units. Among these are weighting class adjustments. One of the metho...

2012
Sarah C. Anoke Nicholas J. Horton Yuting Zhao

Many scientific computations can be sped up by dividing them into smaller tasks and distributing the computations to multiple systems for simultaneous processing. Such a process is referred to as parallel computing. When performed on existing grids of computers, this method can dramatically decrease computation time. Several solutions exist to facilitate this type of computation within R, and w...

this thesis attempts to investigate the effects of prelistening activities on enhancing iranian efl learners` listening comprehension. the present study investigated ways in which learners` background knowledge could be activated in order to enhance their l2 listening comprehension by limiting the number of possible text interpretations prior to listening. the experiments conducted in this study examined the effect of prior knowledge and vocabulary teaching on iranian efl learners listening comprehension. the current study has two purposes: one is to investigate the effect of background knowledge on the second language listening comprehension of iranian intermediates and the other is to determine whether second language is facilitated by the introduction of unknown vocabularies in the form of prelistening activities. to conduct the study different instruments such as listening proficiency test and four listening tests such as pre and posttests were used and various statistical processes and techniques including paired-sample t-test, and analysis of variance (anova) were used. the findings of this study supported all three hypotheses tested. differences were found between the means of preteaching vocabulary variable, the background knowledge activation variable, and mean difference between these two strategies variable. subjects scored higher when the unknown words were taught in advance. likewise, subjects scored higher when they were asked some relevant questions about the topic than on those without them. there was, in addition, a significant difference between the means of preteaching vocabulary strategy and background knowledge activation strategy. in fact, preteaching vocabulary had a better effect in enhancing the students’ listening comprehension, in comparison to background knowledge activation strategy.

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده زبانهای خارجی 1390

this thesis attempts to investigate the effects of prelistening activities on enhancing iranian efl learners` listening comprehension. the present study investigated ways in which learners` background knowledge could be activated in order to enhance their l2 listening comprehension by limiting the number of possible text interpretations prior to listening. the experiments conducted in this stud...

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