Are There Rival Causes? CSIT58 Chapter 10
Rival Cause • Another reasonable interpretation that can explain why a certain outcome occurred. • The same evidence can be consistent with different analysis.
Clues for Detecting Rival Causes • Can I think of any other way to interpret the evidence? • What else might have caused this act or these findings? • If I looked at this from another point of view, what might I see as important causes? • If this interpretation is incorrect, what other interpretation might make sense?
The Cause or A Cause • A common error is to look for a simple, single cause of an event when it is really the result of many contributory causes. Only 18 percent of U.S. households currently subscribe to broadband Internet services such as cable modems or DSL, according to TNS Intersearch. Most people are satisfied with their dial-up connections.
The Cause or A Cause People may be sticking with their dial up connections for any or all of the following reasons: • Reliable broadband is not available in their area • They don’t understand the advantages of broadband • Broadband is more expensive to install with higher monthly charges. • Their older computer is not equipped for a broadband connection.
Differences Between Groups • Researchers find differences between groups and conclude that the differences support their hypothesis. Ms. Lane’s online CIS1 students have higher total scores on average than the night face-to-face CIS1 class. Both classes are given the same assignments and tests. Online learning is more effective for introductory computer classes.
Differences Between Groups • Problem: research groups almost always differ in more than one important way. • Students who sign up for an online class may be more familiar with computers to start with. • Students who are successful in online classes have to be self-motivated and may get higher grades in general. • Students who take courses at night may have less time to spend and the 3 hr class time is very long to pay attention.
Confusing Causation with Association • We have a tendency to “see” events that are associated, or that “go together” as events that cause one another. • Conclude that because characteristic X is associated with characteristic Y, that X therefore causes Y.
Women in Computer Fields "Usually starting around the middle school years and puberty, girls start to get a message that computing is for boys," said Jo Sanders, director of the Computer Equity Expert Project, a New York-based group that received federal funding to train computer teachers in how to reach girls. "If there's a computer club after school, they see boys there. If they walk by a computer store downtown, the salespeople are men. If they see ads for computers, the people in the ads are men ... .They get the idea that computing is male” DeBare, Ilana. “Computer Classes Lack Key Feature: Girl’s Faces.” SACBEE. 1996. http://www.sacbee.com/static/archive/news/projects/women/wcschools.html (12 Nov. 2002)
Possible Explanations • Explanation 1: X is a cause of Y Girls don’t like to study computers because role models are male. • Explanation 2: Y is a cause of X The role models are male because girls don’t like to study computers.
More Possible Explanations • Explanation 3: X and Y are associated because of some third factor Z "The image of the computer scientist as a 'nerd' was something I heard a lot about from my daughters," said Anne-Louise Radinsky, chairwoman of the computer science department at California State University, Sacramento. "I think the image was very much a problem for them." Factor Z is the “nerd” factor.
More Possible Explanations • Explanation 4: X and Y influence each other: For girls who do venture into computer science classes, the small numbers can be discouraging. Dok Lam, a 16-year-old junior at San Juan High School, almost dropped out of Grant McMicken's programming class when she realized she was practically the only girl. "I said, 'I don't think I belong here, it's all guys,'" Lam recalled. Girls don’t study computers because it’s all male, and it’s all male so girls don’t study computers!
Confusing “After this” with “Because of this” • Try to explain an event by saying: Because event B followed event A, then event A caused event B. • Also called post hoc fallacy
Chain of Events • Many events that occur close together in time do not do so because one causes the other. Hewlett Packard’s stock price went from over 60 when Carly Fiorina became CEO in July 1999 to 28 today. Putting a woman in charge ruined the company. (Fall 2005)
Truth or Coincidence? • Timing of events may be just a coincidence. Or there may be a real connection! • The prices of most technology stocks have declined since 1999. Can we be sure that HP’s stock price is due to Ms. Fiorina’s mismanagement? • Maybe there were other factors such as increased competition? • It’s possible she really is an incompetent CEO. • Can you generalize to all female CEOs? Carly lost her job in Feb. 2005
Fundamental Attribution Error • We overestimate the importance of personal tendencies relative to situational factors in interpreting the behavior of others. I asked my husband to pick up some things at Trader Joes when he went to exercise at Bally’s. I came home and opened the refrigerator to find that he didn’t do it. I got mad, assuming that he forgot or wasn’t listening (as often happens when the TV is on). Turns out there was a power failure and the shopping center was shut down that evening.
Apple vs. Microsoft Apple Computer, Inc. has failed to convince computer users that its systems are better than those of its largest competitor, Microsoft. How do we know? Just look at the market share of each company’s respective operating systems. Of the estimated 490 million personal computers in use, 468 million are non-Mac PCs-the vast majority of which use Windows. Mac OS, by comparison, is used on a mere 22 million computers, about 4.5 percent of the total market share. Consumers have stated their preference, and Windows is it. (From page 161 in Asking the Right Questions 6th Edition)
A Conclusion and Reason Conclusion: People prefer to use Windows over Mac OS Reason: Out of all of the personal computers in use, only 22 million are Mac OS. Are there other possible causes?
Alternative Causes • Non-Mac PCs are easier to buy (more alternative brands, more widely available). • Non-Mac PCs may be cheaper. • More software runs on non-Macs The consumer may prefer Mac but is pushed toward buying a non-Mac PC. Note: The newest PCs from Apple with Intel processors now run Windows.