Descriptive Analytics I: Nature of Data, Statistical Modeling, and Visualisation - Regression Modelling for Inferential Statistics

6 important questions on Descriptive Analytics I: Nature of Data, Statistical Modeling, and Visualisation - Regression Modelling for Inferential Statistics

What is regression and what statistical purpose does it serve?

Regression is relatively simple statistical technique to model the dependency of a variable (response or output variable) on 1 (or more) explanatory (input) variables.
It can be used for:
  1. hypothesis testing (theory building): investigating potential relationships between different variables. It can reveal the strength and directions of relationships between a number of explanatory variables and the respons variable.
  2. Prediction/forecasting: estimating values of a response variable based on 1 or more explanatory variables. The equation is used to predict.
Report

What are the commonalities and differences between regression and correlation?

Correlation: is not concerned with te relationship between variables. It gives an estimate on the degree of association between the variables?
regression: attempts to describe the dependence of a respons var. on 1 (or more) explanatory vars. Implicit assumption that there is a 1-way causal effect.
Report

What is OLS? How does OLS determine the linear regression line?

OLS: Ordinary Least Squares: is a method/algorithm to identify the regression line. It leads to the mathematical expression for the estimated value of the regression line.
Report

List and describe the main steps to follow in developing a linear regression model?

tbd
Report

What are the most commonly pronounced assumptions for linear regression?

Linearity: linear relationship between vars.
Independence (of errors): the errors of the response variable are uncorrelated of each other.
Normality (of errors): the errors of the response variable are normally distributed
Constant variance (of errors): the errors of the response variable have the same variance. Assumption is invalid if resp.vars. over a wide enough range.
Multicollinearity: the explanatory variables are not correlated.
Report

What is time series? What are the main forecasting techniques for time series data?

Is a sequence of data points of the variable of interest, measured and represented at successive points in time spaced at uniform time intervals.
naïve forecast: today's forecast is the same as yesterday's actual
ARIMA: very complex: combination of AutoRegressIve and Moving Average patterns
Averaging methods: simple average, moving average, weighted moving average,...
Report

The question on the page originate from the summary of the following study material:

  • A unique study and practice tool
  • Never study anything twice again
  • Get the grades you hope for
  • 100% sure, 100% understanding
Remember faster, study better. Scientifically proven.
Trustpilot Logo
  • Higher grades + faster learning
  • Never study anything twice
  • 100% sure, 100% understanding
Discover Study Smart