The present study attempted to investigate the writing performance of EFL learners through process vs. product writing on IELTS test. To do this, the researcher randomly selected 60 candidates who wanted to take the IELTS Test. They had already taken and passed several technical courses regarding the skills in that test. After they were divided into two experimental groups, they were given a wr...

Objective To find lower and upper bounds of HIV prevalence in Malawi under mild and intuitive assumptions to assess the importance of the refusal issue in the estimation of HIV prevalence. Methods We derive bounds based on the following two key assumptions: (i) Among those who have never taken an HIV test before, those who refuse to take an HIV test (hereafter “refusers”) have at least as much ...

This paper gives identification and estimation results for quantile and average effects in nonseparable panel models, when the distribution of period specific disturbances does not vary over time. Bounds are given for interesting effects with discrete regressors that are strictly exogenous or predetermined. We allow for location and scale time effects and show how monotonicity can be used to sh...

The problem of providing lower confidence bounds for the mean improvements of p ≥ 2 test treatments over a control treatment is considered. The expected average and expected maximum allowances are two criteria for comparing different systems of confidence intervals or bounds. In this paper, lower bounds are derived for the expected average allowance and the expected maximum allowance of Dunnett...