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...

the study reflected in this thesis aims at finding out relationships between critical thinking (ct), and the reading sections of tofel and ielts tests. the study tries to find any relationships between the ct ability of students and their performance on reading tests of tofel and academic ielts. however, no research has ever been conducted to investigate the relationship between ct and the read...

abstract: about 60% of total premium of insurance industry is pertained?to life policies in the world; while the life insurance total premium in iran is less than 6% of total premium in insurance industry in 2008 (sigma, no 3/2009). among the reasons that discourage the life insurance industry is the problem of adverse selection. adverse selection theory describes a situation where the inf...

this study investigates the effect of teacher’s repetition as an input enhancement technique in explicit teaching of vocabulary items on efl learners’ later retrieval. to this end, 66 persian speaking english learners, aged 18 - 29, homogenized through a standard proficiency test (opt), were chosen and put into two experimental and control groups, each 33 learners. general service list (gsl), a...

in this thesis, barium ferrite nano particles were prepared by sol-gel method. their structural and magnetic properties of samples have been investigated using thermo gravimetric analysis (tg-dta), x-ray powder diffractometer (xrd), fourier transform infrared (ftir), scanning electron microscopy (sem), field emission scanning electron microscopy (fesem), ac susceptometer, vibrating sample magne...

language learning courseware has been receiving growing attention by english educators since its advent. a variety of softwares have been designed by software designers and resorted to by language educators to supplement language textbooks. this experimental study investigated how the application of computerized version of language textbooks and the reception of the entire course through comput...

abstract this study evaluates the iranian pre-university english textbook in terms of needs, objectives, content, and methodology. the study was designed on the qualitative- quantitative survey basis using interviews and questionnaires, a researcher-made textbook evaluation checklist and a needs analysis questionnaire. the textbook evaluation questionnaire was used in this study to elicit the ...

the methods which are used to analyze microstrip antennas, are divited into three categories: empirical methods, semi-empirical methods and full-wave analysis. empirical and semi-empirical methods are generally based on some fundamental simplifying assumptions about quality of surface current distribution and substrate thickness. thses simplificatioms cause low accuracy in field evaluation. ful...

why some learners are willing to communicate in english, concurrently others are not, has been an intensive investigation in l2 education. willingness to communicate (wtc) proposed as initiating to communicate while given a choice has recently played a crucial role in l2 learning. it was hypothesized that wtc would be associated with language learning orientations (llos) as well as social suppo...

in recent years many researchers have been focused on interaction of small molecules with dna. dna is generally the primary intracellular of anticancer drugs, so the interaction between small molecules and dna can cause dna damage in cancer cells, blocking the division of cancer cells and resulting in cell death. the flavonoids are a large group of polyphenolic natural products that are widely ...