Learning statistical concepts

Abstract

In order to learn the concept of statistical techniques one needs to run real experiments that generate reliable data. In practice, the data from some well-defined process or system is very costly and time consuming. It is difficult to run real experiments during the teaching period in the university. To overcome these difficulties, statisticians developed simple and very economical experiments, which can be performed in the class by the students. Stone studied the variation, bias, stability and statistical quality control through the Blind Paper Cutting (BPC) experiment. In this article, the Blind Paper Cutting experiment is demonstrated on the basis of basic principles of experiment design. A BPC experiment is performed considering different factors, and important factors to optimise the response are identified through complete factorial design. The appropriate response model using important factors has been constructed.

Natural and drinking water quality in Erbil, Kurdistan

“…Furthermore, the characteristics of greater Zab river was studied by other researchers during 2004 -2005 [33][34] , they explained the high turbidity of the river's water by inefficient treatment or resuspension of sediment and the surface run off that enters the river. Their results showed that Greater Zab River water can not be used for drinking directly.…”

“…At the same time, these authors observed a low level of nitrate which was attributed to the effect of macro-microphyte which utilizes the inorganic nitrate. Akram et al 34 , monitored monthly the quality of water samples from Kasnazan Impoundment during Aug 2004 -Feb 2005. Statistical analysis indicated that there was a significant difference between kahreez (site 1) and other sites in TDS and HCO 3 values while there was no significant difference in K concentration between the locations or times.…”