Question

Suppose that an analyst used text mining to study a pool of “true or false” questions that appeared in exams and quizzes, and had the following observations:

80% of all statements are true

10% of all statements contain a cue word in the set {“Always”, “Never”, “All”}

2% of true statements contain a cue word and 40% of false statements contain a cue word

False statements tend to be brief (i.e., containing less than 10 words) and true statements tend to be long. Specifically, 30% of false statements are brief and only 5% of true statements are brief.

Use Bayes Theorem and Naïve Bayes method to answer the following questions.

Given that a statement contains a cue word, what is its probability of being a true statement? (7 credits)

How would you classify the following statement using Naïve Bayes principle, i.e., is it a true statement

or a false statement? Show your calculations. (8 credits)

Statement: “All models are wrong.”

Answer 1

Problematic situations that have occurred for SWA since the Air Trans takeover which was to some extent associated to the new leadership management appointed in 2001. These dramatic changes have created difficulties in the SWA’s culture, along with the increasing costs in fuel and wages. They remain committed to the pillars of their success—outstanding Customer Service; safe, reliable, and efficient operations; and low costs.

Since the leadership change the company has engaged in a path of actions that have produced radical change in the organizational cultural and the company’s operational methodology. Instead of working at teamwork, there has been increasing distance between employees, managers and top management. SWA Airlines tries to save money by simplifying its operating process by utilizing strategies such as having one type of aircraft which allows its mechanics to be experts on that one airplane model saving maintenance time, parts thus lowering costs. SWA utilizes a point-to-point strategy (fly customers direct from point to point) as opposed to the hub and spoke system (fly customer to a gathering airport {hub}) competitors operate with in their systems. This is the most efficient way of adopting the concept of high average velocity and maximizes passengers per miles revenue mile. The booking cost per passenger online is "well under $1," said Kelly, and is scaling down even further. SWA uses the Market-Focused Management Model. It believes the company should trust and stand on its employees’ side because sometimes customers might be wrong. SWA claims, “Ownership is the result of believing you can make a difference, then acting on that belief in everything you do.”