Research Methods Essay Example | Topics and Well Written Essays - 1000 words - 5

Research Methods - Essay Example The independent variables negatively correlated with the dependent variable: number of MP3s, and age. The model is a poor model in explaining CD sales because the adjusted R2 is only 0.27. Nevertheless, the F-statistics is significant with a p-value of 0.001. This means that we can reject the null hypothesis that all coefficients of the independent variables of the model are simultaneously equal to zero. Thus, unless a better model is found, the model may be used on a provisional basis. For inferences to be appropriate, several assumptions are assumed to apply in multiple regressions (Gujarati 2004, p. 203), there are several assumptions involved in using linear regression. The most important of these are as follows: zero mean of residuals, no serial errors among residuals, homocedasticity, zero covariance between independent variable and residuals, absence of specification bias or the model is correctly specified, and no exact collinearity between the independent variables (Gujarati 2004, p. 203 and 204). Except for gender and age, all variables are able to provide a significant explanation on the value of the dependent variable. The variable â€Å"task control,† however, is able to explain at a significant level the dependent variable in Netherlands but not in the US. Except for tenure, the background variables are unable to provide a significant marginal contribution in explaining the value of the dependent variable. The variables task control environment control, and tenure consistently manifest a negative relationship and all are significantly related at p-value=0.10 with the dependent variable perceived work stress. That greater job control can significantly affect the perceived work stress is adequately supported in both regressions. However, I am uncomfortable that the both regression model can only explain not more than 25% of the variation