Modeling of Engineering Management Systems
Problem Statement - Review one research article in the area of engineering (construction/civil/mechanical/chemical/electrical) that includes one of the Statistical modelling techniques cite below. The article must be directed at a scholarly audience. State clearly the research question, the experiment carried, the author interest, state clearly the hypothesis intended to be tested by the selected article using Statistical modelling techniques. Describe the dependent variable-the independent variables-the factors. You need to discuss the type of data and its source (give a brief overview of how the data was acquired, collected, observed or measured).
Discuss the findings, the tests of the assumptions. Give interpretation of the results and discuss the author conclusion in relation to the findings.
In case you have access to the research data, carry out the checking of the assumptions. You may even replicate the research (Reverse Engineering). The scientific article should have been published in ranked journals A or B.
Regression / Regressing with categorical variables/ Logistic Regression
Question 1 - A law firm has been asked to investigate whether employees' experience and their quality of work were taken into consideration when Salary Increase was made by the supervisor. A random sample of 17 employees was drawn from the company file and based on the three variables
1) Salary increase of the employee (in 100 AED)
2) Quality of work: Employee performance rating measure (scale 1-100)
3) Experience: The number of years since the employee was hired (in years)
Based on the data collected, Multiple regression was conducted of Salary increase on the two predictors namely Quality of work and experience. The regression results are provided below:
a) Write the multiple regression equation:
b) Interpret the meaning of the coefficient of determination
c) Interpret the two partial slope coefficients
d) Write down another potential variable that could be included in the analysis
e) Predict the salary increase of a person given his/her Quality of work = 60 and with 6 years of experience.
Question 2 - What are the assumptions of the regression?
What is the role of the disturbance term in regression analysis?
Distinguish between Types of errors that can be made during hypothesis decision.
Define what is meant by perfect multi-collinearity and what are the consequences?
Define what is meant by severe multi-collinearity and what are the consequences?
State the various techniques for detecting multi-collinearity.
In which case when conducting multiple regression dummy trap situation may occur?
Question 3 - Working with categorical variables Interaction models
Model without interaction including a binary variable
Y= β0 + β1colgpa + β2 Athelete
Explain in which case, an interaction model is necessary.
Explain how you would interpret the interaction model.
Question 4 - Interpreting Regression results
A research study aims to find the relationship between SAT scores, and two other factors namely gender and athlete. To this end, based on past data of 4136 students who took SAT, multiple regression of the SAT on all the variables. The regression results are given below:
a) Conduct Colgpa significance using confidence interval approach at α=0.05
b) Which variables are significant (explain) (use α=0.05). Interpret your model.
c) Interpret the coefficient corresponding to the independent variable verbmath.
d) Interpret the coefficient corresponding to the independent variable athelete.
e) Interpret the R-square.
g) Predict the SAT score for an athlete student with colgpa =3.4, tothrs =78 and Verb/Math =0.95
Question 5 - Researchers want to investigate the relationship between subjects' scores on a test of empathy and their gender, age in years, whether they were a parent or not, and education level in years.
a. Which test would you use?
1. Simple linear regression
2. Multiple regression
3. Logistic regression
4. ANOVA
5. Two-way ANOVA
6. Repeated measures ANOVA
b. What are the null and alternative hypotheses?
Question 6 - a. Is it true to meet the equal variance assumption you want Levene's test to be significant.
b. Write the hypothesis related to Levene Test.
What is the purpose of the Logistic Regression?
Explain what the response variable is in a logistic regression.
Assignment Files -
https://www.dropbox.com/s/6z9vhonc2j6biqr/Assignment%20Files.rar?dl=0