Thursday, February 27, 2020

Regression Analysis Speech or Presentation Example | Topics and Well Written Essays - 750 words

Regression Analysis - Speech or Presentation Example In essence, it allows for evaluation of the fixed and random effects models in non-linear modeling frameworks and simply assumes parameter and variable non-linearity. Assumption 2: Expected value of error is zero This assumption presumes that the error component will return a zero mean meaning that the observed mean will not be systematically distorted away from the true value by the error (and this contrasts with a systematic bias effect which would distort the observed mean away from its true value) (Good & Hardin, 2009). Assumption 3: Autocorrelation Amongst the assumptions often made in regression analysis is that error terms not dependent on each other or rather non-correlated. This is however not always the case. When this assumption is violated, despite the fact that the regression model is still usable, in prediction value, its usefulness is largely diminished. This study considering the relationship between the variables seeks to assume its presence and hence proof that the model’s usability is largely diminished. The estimated regression parameters, a, b1, b2, . . . ,bk, are left as unbiased estimators of the respective real values, A, B1, B2, . . ,Bk, and hence the model remains appropriate for establishment of point estimates of A, B, and others., and it can be used in prediction of values of Y for X value sets (Good & Hardin, 2009) (Good & Hardin, 2009). Autocorrelation is often a product of errors correlation. It broadens the scope of thinking to look at different observations which result from varying distributions which are non-explanatory. Assumption 4: Heteroskadascity Sphericality assumption often implies that there exists homoskedasticity of errors, and that variance is constant across cases. Violation of this offers heteroskedasticity whereby the predictive model does particularly poor in some set of circumstances. Take for instance in this case where there is a possibility that unemployment or gas prices across countries may be reli able but there is lesser proof to believe in the data relating to the same obtained from other countries. Such a case would give rise to increased random variation, and hence huge mean error variances, in the respective countries. In general, Heteroskedasticity occurs in instances where the homoskedasticity assumption is violated, giving rise to Assumption 5: Multi-collinearity assumption Whenever there exists moderate to high intercorrelation amongst predictor variables, multi-collinearity is believed to arise. Typically, multi-collinearity presents a real research problem when multiple regressions are used. These include its severe limiting of R’s size given that predictors follow a variance as much the same as that of y, creating a difficulty in determination of the worth of a predictor due confounding of the effects as a result of correlation between them, and an increment in regression coefficient variants (Good & Hardin, 2009). In this case’s, a number of variabl es are considered in the model including gas price, excluding food prices, unemployment, and personal expenditure which was removed due to its high correlation to the other variables. However, even with the inclusion of the other variables, it is still believed that the other variables have some slight correlation to each other. For instance, food services are likely to be impacted on by gas prices and the same is true for unemployment rates. Conclusion Understanding relationship

Tuesday, February 11, 2020

Criminology and criminal justice studies Essay Example | Topics and Well Written Essays - 3000 words

Criminology and criminal justice studies - Essay Example This essay investigates the organized deviance as revealed in the activities of a gang named Aggi Crew in St. Paul’s area of Bristol. This was a notorious drug-peddling gang whose members sometimes involved in street brawls with rival gangs in the area. Their dastard actions have sometime invited armed police to be constantly station on St. Paul with the intention of preventing the gangsters from flouting laws and terrorise innocent citizen in the area (BBC, 2003). Though some of the gang’s activities would be explained here, however, the central goal of this paper is to detail the appropriate responses from the concerned criminal justice systems. member’s surname. The gang’s main activity is to peddle drugs locally in the areas of Bristol. Sometimes they were engaged in street fights with rival gangs. What made the Bristol residents unsettled and greatly worried about Aggi Crew was the fact that they had had deadly weapons and guns in their possessions. They had also been involved in armed robbery at the famous White and Black Cafà ©, a place that was rumored to be the melting-pot for both drug buyers and sellers (Thompson, 2003). Judging by the explosion of gangsters’ criminal activities in Britain, the question every thoughtful person may want to ask is: are there any legal provisions to combat this plague of violent gang crime in the United Kingdom? Critically, there are some laws and statutes of Her Majesty that are enacted for the purpose of preventing all kinds of crime in Britain, including drug and violent crimes mostly committed by gangs. Incidentally, Misuse of Drug Act 1971 is meant to discourage the use, sale and spread of harmful drugs like cocaine, heroin and other stimulants; The Firearms Act 1968 totally discourages the use of firearms for the purpose of causing harm and damage to other people and their properties; Criminal Justice Act 2003establishes the modalities