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Usability professionals salary survey. The Usability
Chapter 12, Problem 9E(choose chapter or problem)
Usability professionals salary survey. The Usability Professionals’ Association (UPA) supports people who research, design, and evaluate the user experience of products and services. Recently, the UPA conducted a salary survey of its members (UPA Salary Survey, August 18, 2009). One of the report’s authors, Jeff Sauro, investigated how much having a PhD affects salaries in this profession and discussed his analysis on the blog, www.measuringusability. com. Sauro fit a first-order multiple regression model for salary (y, in dollars) as a function of years of experience (\(x_1\)), PhD status (\(x_2 = 1\) if PhD, 0 if not), and manager status (\(x_3 = 1\) if manager, 0 if not). The following prediction equation was obtained:
\(\hat{y}=52,484+2,941 x_{1}+16,880 x_{2}+11,108 x_{3}\)
a. Predict the salary of a UPA member with 10 years of experience who does not have a PhD, but is a manager.
b. Predict the salary of a UPA member with 10 years of experience who does have a PhD, but is not a manager.
c. The following coefficient was reported: \(R_a^2 = .32\). Give a practical interpretation of this value.
d. A 95% confidence interval for \(\beta_1\) was reported as (2700, 3200). Give a practical interpretation of this result.
e. A 95% confidence interval for \(\beta_2\) was reported as (11,500, 22,300). Give a practical interpretation of this result.
f. A 95% confidence interval for \(\beta_3\) was reported as (7,600, 14,600). Give a practical interpretation of this result.
Questions & Answers
QUESTION:
Usability professionals salary survey. The Usability Professionals’ Association (UPA) supports people who research, design, and evaluate the user experience of products and services. Recently, the UPA conducted a salary survey of its members (UPA Salary Survey, August 18, 2009). One of the report’s authors, Jeff Sauro, investigated how much having a PhD affects salaries in this profession and discussed his analysis on the blog, www.measuringusability. com. Sauro fit a first-order multiple regression model for salary (y, in dollars) as a function of years of experience (\(x_1\)), PhD status (\(x_2 = 1\) if PhD, 0 if not), and manager status (\(x_3 = 1\) if manager, 0 if not). The following prediction equation was obtained:
\(\hat{y}=52,484+2,941 x_{1}+16,880 x_{2}+11,108 x_{3}\)
a. Predict the salary of a UPA member with 10 years of experience who does not have a PhD, but is a manager.
b. Predict the salary of a UPA member with 10 years of experience who does have a PhD, but is not a manager.
c. The following coefficient was reported: \(R_a^2 = .32\). Give a practical interpretation of this value.
d. A 95% confidence interval for \(\beta_1\) was reported as (2700, 3200). Give a practical interpretation of this result.
e. A 95% confidence interval for \(\beta_2\) was reported as (11,500, 22,300). Give a practical interpretation of this result.
f. A 95% confidence interval for \(\beta_3\) was reported as (7,600, 14,600). Give a practical interpretation of this result.
ANSWER:Step 1 of 6
(a)
Estimate the salary of a UPA member with 10 years of experience who does not have a PhD, but is a manager.
Here, the dependent variable is salary and the independent variables are experience, PhD status, and manager status.
The regression equation for the model is,
Thus, the predicted value of a member does not have PhD, but manager with 10 years of experience is as follows:
Hence, the predicted salary is 