Estimate the logistic regression model
Course:- Basic Computer Science
Reference No.:- EM131239002

Assignment Help
Expertsmind Rated 4.9 / 5 based on 47215 reviews.
Review Site
Assignment Help >> Basic Computer Science

Continuing Exercise 4 in Chapter 2, consider the model using temperature as the only explanatory variable.

(a) Refit the model using a probit and a complementary log-log link instead of a logit link. Plot all three curves with the data, using a temperature range of 31? to 81? on the x-axis. Does one appear to fit better than the others? Do they provide similar probabilities of failure at 31??

(b) Compare BIC values for the three different links. Which link appears to fit best?

(c) Compute the BMA model probabilities for the three links. Comment on the uncertainty of the model selection among these three links.

Exercise 4

The failure of an O-ring on the space shuttle Challenger's booster rockets led to its destruction in 1986. Using data on previous space shuttle launches, Dalal et al. (1989) examine the probability of an O-ring failure as a function of temperature at launch and combustion pressure. Data from their paper is included in the challenger.csv file. Below are the variables:

• Flight: Flight number

• Temp: Temperature (F) at launch

• Pressure: Combustion pressure (psi)

• O.ring: Number of primary field O-ring failures

• Number: Total number of primary field O-rings (six total, three each for the two booster rockets)

The response variable is O.ring, and the explanatory variables are Temp and Pressure. Complete the following:

(a) The authors use logistic regression to estimate the probability an O-ring will fail. In order to use this model, the authors needed to assume that each O-ring is independent for each launch. Discuss why this assumption is necessary and the potential problems with it. Note that a subsequent analysis helped to alleviate the authors' concerns about independence.

(b) Estimate the logistic regression model using the explanatory variables in a linear form.

(c) Perform LRTs to judge the importance of the explanatory variables in the model.

(d) The authors chose to remove Pressure from the model based on the LRTs. Based on your results, discuss why you think this was done. Are there any potential problems with removing this variable?

Put your comment

Ask Question & Get Answers from Experts
Browse some more (Basic Computer Science) Materials
Consider the economy of a small country. For each labor hour, it has capital stock equal to 900 units. In the current year it produced 20 units of new capital goods, with a
How long would this address assignment last? At the time when the company runs out of address space, how would the addresses be assigned to the three groups? (c) If CIDR add
If Mozilla Firefox is set as your default browser, copy and paste the link into a different web browser to access the article. Here Dr. Cecil Wilson,President of the America
The help desk is the point at which every frustration, every concern, and every mistake known to humanity is brought for resolution. Typically staffed by lower-level and oft
Review the five types of customer complainers and the four types of complaints. Then, below describe a time when you did not "complain" - What caused you not to provide this
What are the possible sets of sequence numbers inside the sender's window at time t? Justify your answer.What are all possible values of the ACK field in all possible messages
Ethanol, a fuel, is made from corn. Ethanol production increased 5.5 times from 2000 to 2008 (www .ethanolrfa.org, May 2010). What effect did this increased use of corn for
c) Could the Mark 100 or Mark 200X process this string: 0n1n? How about 1n0m1m0n? Succinctly justify you answer. d) How does the power of the Mark 100 and Mark 200X compare