1. Who Plays Video Games? Saumitra Sahi

2. Introduction In U.C. Berkeley, some kinds in the statistics class uses an alternative method to learning statistics and probability. They use computer labs, which for some students feel like an educational video game. The committee that designed the lab created a survey to determine the extent to which the students play video games and which aspects of video games they find most and least fun.

3. Questionnaire How much time did you spend last week playing video and/or computer games? Do you like to play video and/or computer games? What types of games do you play? Why do you play the games you checked above? Where do you usually play video/computer games? How often do you play? Do you still find time to play when you’re busy? Do you think video games are educational? What don’t you like about video game playing? Sex? Age? When you were in high school was there a computer in your home? What do you think of math? How many hours a week do you work for pay? Do you own a PC? Does it have a CD-Rom? Do you have an e-mail account? What grade do you expect in this class?

4. The Data A simple random sample of 95 from the Statistics 2, Section 1 during Fall 1994 class of 314 students was taken. 91 of the 95 responded. The purpose of the questionnaire was to find out –The extent to which the students play video games –Which aspects the students find most fun –Which aspects the students find least fun

5. Frequency of Play TypePercent Action50 Adventure28 Simulation17 Sports39 Strategy63 According to the above table, at least 63% of the students play games What types of games do you play?

6. Frequency of Play The table shows the amount of time put into playing video games a week before the questionnaire. Most people do not play video games in the course. TimeCountBootstrap 057197.113.5517 15 1.514 21448 3311 413 514 1427 3013 Total91314

7. Frequency of Play Though the majority of students do not play games, there is a rough normal distribution among those that actually played video games, with a mean at about 2 hours (denoted by 6 on the histogram)

8. Why do you play the games you checked? Aspects they like Why?Percent Graphics/Realism26 Relaxation66 Eye/Hand coordination 5 Mental Challenge24 Feeling of Mastery28 Bored27 Most people play video games for relaxation

9. Aspects they dislike Many people feel video games take too much time, so they do not like to play it. DislikesPercent Too much time48 Frustrating26 Lonely6 Too many rules19 Costs too much40 Boring17 Friends don’t play2 It’s pointless33 What don’t you like about video games?

10. Conclusions The majority of students in the Statistics 2, Section 1 course in Fall ‘94 did not play video games. The majority of the students who did not like video games felt it was a waste of time. Those who did play video games averaged around two hours per week. The majority of those who like playing video games play for relaxation.

11. A Twist to the Study After seeing these results from the Statistics Course at UC Berkeley, I decided to do the same survey for the 4 th Period Statistics Class and do a statistical inference (chi-square test) about the goodness of fit for the results to see if the UC Berkeley results from 1994 hold with PHS results from 2007.

12. Aspects we like Similar to U.C. Berkley’s results, relaxation is still the number one aspect students like about video games. Why do you play the games you checked? Why?Percent Graphics/Realism31 Relaxation80 Eye/Hand coordination 15 Mental Challenge38 Feeling of Mastery31 Bored54

13. What we are expected to like According to what the UC Berkeley students like about video games, if our class has the same preferences, our percentages would be expected to be these. CAUTION: Since we are about to embark upon a goodness of fit test, we need to be sure that all individual counts (percentages in this case) are at least 1 and no more than 20% of the expected counts are less than 5. –Since these conditions are met, we can continue. Why?Percent Graphics/Realism36 Relaxation92 Eye/Hand coordination 7 Mental Challenge33 Feeling of Mastery39 Bored37

14. Hypotheses When doing a goodness of fit chi-square test, we have two hypotheses –Null Hypothesis (H 0 ) : The proportions are still the same –Alternate Hypothesis (H a ): At least one proportion is wrong.

15. Test Statistic In order to obtain a test statistic which should aid us in determining if the proportions still hold we need to plug our results into this formula, where O i is the observed value, and E i is the expected value. After this calculation, we get the chi-square value to be 21.61. Now we are ready to obtain the P-value

16. P-value The P-value needs to be less that an a-value. Let us have 95% confidence in this calculation, therefore we will have an a-value of 5%. Using the test statistic, we calculate a P-value. Only if the P-value < a-value can we reject H 0 and accept H a. Otherwise we fail to reject it. We can easily calculate the P-value in this case using a calculator. We use the x 2 cdf( function, with the desired syntax of (chi-square test statstic, infinity, df). The df is the degrees of freedom which is simply the number of categories minus one. In this case, df = 5. Our P-value turns out to be 0.0006204 which is less than our a-vaule of 0.05, rejecting H 0 and accepting H a.

17. Aspects we dislike Unlike U.C. Berkeley’s class, the major con to playing video games was that it was frustrating to play. What don’t you like about video games? DislikesPercent Too much time31 Frustrating54 Lonely15 Too many rules15 Costs too much38 Boring15 Friends don’t play15 It’s pointless23

18. Goodness of fit test We run through a similar test for the aspects we dislike. With all conditions met, we run through the test with 95% confidence, a chi-square value of 137.65, and df of 7. We obtain a P-value of 5.6 E -28, which is practically zero. This is less than the a- value of 0.05, rejecting H 0 and accepting H a.