Who?s Deviant? Prof. Amori Mikami TA Kathleen Schmidt 3-005 When do we use each? Mean= most of the time; When distribution is symmetrical; when using numerical values Median= when distribution is skewed; When there?s outliers Mode= when there?s categorical data; when distribution is bimodal (e.g., lot of people giving answers at a high number, and a lot of people giving answers at a low number, with little in between) Hours studying last week? Mean=64/16=4 Median=4 is the middle number Mode=4 is the most frequent value Hours studying last week? Mean=77/16=4.8 Median=4 is the middle number Mode=4 is the most frequent value Hours studying last week? Mean=77/18=9.9 Median= (6+16)/2 =11 Mode=4 and 18 are both the most frequent values What kind of pet do you have? Mean=N/A Median= N/A Mode=No pets I-clicker: Who?s Deviant? Strangest celebrity baby name? Apple (Gwyneth Paltrow) Knox Leon (Brangelina) Bronx Mowgli (Ashley Simpson) Zuma Nesta Rock (Gwen Stephani) Kal-el (Nicholas Cage) Variability of Data: Why it Matters My real dataset of 125 children ages 6-10 Children with ADHD have 3.8 playdates per month Children without ADHD have 7.2 playdates per month Fictional Example 1 ADHD kids: 3, 3, 4, 4, 4, 4, 4, 4, 4, 4 Mean: 3.8 Comparison kids: 7, 7, 7, 7, 7, 7, 7, 7, 8, 8 Mean: 7.2 Fictional Example 2 ADHD kids: 0, 0, 0, 0, 0, 0, 0, 0, 0, 38 Mean: 3.8 Comparison kids: 0, 0, 0, 0, 0, 0, 0, 0, 0, 72 Mean: 7.2 Iclicker In which fictional example would you think the differences between ADHD kids and non-ADHD kids is more important? The first example The second example I?m not sure ADHD Frequency .00 10 1.00 7 2.00 9 3.00 10 4.00 6 5.00 3 6.00 6 7.00 2 8.00 2 9.00 1 10.00 1 12.00 1 18.00 1 20.00 1 Total 60 Non-ADHD Frequency .00 6 1.00 3 2.00 7 3.00 3 4.00 10 5.00 5 6.00 6 7.00 4 8.00 5 9.00 2 10.00 2 12.00 2 14.00 1 15.00 1 16.00 3 20.00 3 22.00 1 47.00 1 Total 65 Terms for variability of your data Range (lowest to highest) Variance (need formula) ?(X-M)2 N Standard deviation (need formula, but standard deviation is the square root of the variance) I-clicker Would you like to do another example of computing the variance? Yes, that would help me Either doing it or not is ok to me No, time to move on Farr, R. H., & Patterson, C. J. (in press). Transracial adoption among lesbian, gay, and heterosexual couples: Who completes transracial adoptions and with what results? Adoption Quarterly. Measures Transracial families (n = 61 families) Inracial families (n = 45 families) M SD M SD t ?Test (df = 211) Child Behavior Checklist (1˝ to 5 years) Total BP 45.03 9.64 45.07 9.57 <1 Internalizing BP 44.00 10.30 42.88 9.11 <1 Externalizing BP 46.60 9.36 46.36 9.57 <1 Teacher Report Form (1˝ to 5 years) Total BP 47.68 7.65 48.48 9.43 <1 Internalizing BP 45.35 6.94 45.17 9.78 <1 Externalizing BP 49.94 7.45 50.26 9.39 <1 Parenting Scale 2.56 0.49 2.56 0.44 <1 Parenting Stress Index Total parent stress 60.61 12.88 60.28 14.46 <1 Exam prep? Homework 2 posted on Collab which covers this week?s material Homework 3 also posted (but Hwk 3 is for next week?s material) Answers to homeworks will be discussed at review session next Monday, then posted on Collab after Notes sheet Simple calculator Lying with graphs Adjusting anchor points Leaving out data to tell the story you want Grouping data to tell the story you want Interpretation Coke outperformed the generic brand in 005-show taste test Generic brand judged equal to Coke in 005-show taste test I-clicker What was the muddiest point today? How to mathematically calculate the range, variance and standard deviation of a dataset What the range, variance and standard deviation mean (e.g., conceptually what they are getting at) C. Both of the above are confusing D. I?m down like a clown about today?s material