ARIMA modeling Assignment Example | Topics and Well Written Essays - 750 words

ARIMA modeling - Assignment Example In other words, the data for modeling the revenues of Costco Company may probably need differentiation through it is not certain that there is need for differentiation. In addition, the fact that the first six lags fall outside the confidence area shows that the data is non-stationary, that is, there is trend in the revenue function of Costco Company. Even though there is a trend (non-stationary data) it does not necessarily mean that the data should be transformed or differentiated. This decision can only be reached if specific lags such as 12, 24, and 36 are verified in respect to their expected values. That is when the decision to differentiate the data to remove seasonality and trend will be arrived at. In as much as the aspects of being non-stationary and having a trend have been removed through AR(1) as depicted in the ACF graph, the data looks much better though with two positive spikes at lag 1 and lag 3,. The lags 1 and 3 shows that the data is still non-stationary and there is trend in the data. There is need to remove the non-stationary and trend aspects of the data for efficient and effective modeling of the problem. The indication is that the data does not have a mean or constant variance. In order to do this, there is need to further differentiate the data by taking the 3rd different of y since this will remove the seasonality in the data. The above graph shows that there are specific lags that lie outside the confidence area. This means that the data is not stationary. It is important to find the ACF for the other differences such as 1st, 4th, 5th, 6th, and 7th for the purposes of removing aspects of seasonality in the data. These lags exist outsides the confidence level as depicted by the ACF graph. The coefficients are SAR and SMA due to the seasonality present in the data. The p values of both coefficients are below .05. The MS is 466718 for the model.

A Synthesis of Current Literacy Theories Essay Example | Topics and Well Written Essays - 2500 words

A Synthesis of Current Literacy Theories - Essay Example As a result, many scholars have different views on the concept of literacy, which leaves the common person more confused. Indeed, although the term ‘literacy’ is seemingly easier to understand by everybody, it has unfortunately proved to be complex and dynamic concept to interpret or even define. As such, we have many educational theorists, scholars, and newspaper editors defining the concept literacy. In the ancient times, literacy only referred to the ability of a person to read and write at an adequate level of proficiency that would enable them to communicate with others (TakingITGlobal, 2012). However, in the recent times, there is no mutually satisfactory measure of what adequate literacy means. As such, this paper will refer to various scholarly sources in addressing the various theories of literature, the issues that relate to literacy, and an analysis of literacy. Additionally, the paper will elaborate, synthesise, and analyse various perspectives on literacy. F urthermore, the paper will discuss the implications of the application of these perspectives to learning in vocational education and training centres. More so, the paper will analyse the various ways that teachers and trainers can apply the concept of literacy to learning in vocational education and training. Some scholars refer to literacy, as the quality or state of being literate or simply being able to read and write. On the other hand, others associate literacy with creative writing or just having knowledge or competence. Moreover, other educational theorists introduce the aspect of visual literacy in understanding the concept of literacy. As such, they relate visual literacy to the ability to recognize and understand ideas conveyed through visible actions or images. However, according to the National Institute for Literacy, The Workforce Investment Act of 1998 defines literacy as â€Å"an individual's ability to read, write, speak in English, compute, and solve problems at le vels of proficiency necessary to function on the job, in the family of the individual and in society†Ã‚  (Valenzuela,2002). Additionally, the United Nations Educational, Scientific, and Cultural Organization thinks there is more to literacy than just being a set of technical skills of reading, writing, and calculating (United Nations Regional Information Centre for Western Europe, 2012). We may need to consider the factors that influence the multiple understandings of this concept. Notably, academic research, institutional agendas, national context, cultural values, and personal experiences influence individuals understanding on the concept of literacy. Indeed, there are four discrete understandings of literacy that include literacy as an autonomous set of skills, literacy as text, literacy as a learning process, and literacy as applied, practised and situated (Education for All Global Monitoring Report, 2006).The four understandings significantly incorporate almost all theore tical understandings of literacy. However, the most common understanding of literacy is as a set of cognitive skills that involve reading, writing, and oral skills. However, it is worth noting that despite the multiple definition of literacy, the literacy levels vary between the developed and developing nations. Indeed, the rate of literacy in the developed nations is much higher than in the developing nations. Nevertheless, there is a worldwide mission to eradicate illiteracy in the world.