1 / 26

Practice

Practice. 10.15 Did the type of signal effect response time?. t crit (15) = +/- 2.447 t obs = -2.24 Fail to reject Ho The type of signal does not have a significant effect on response time. New Step. Should add a new page Determine if One-sample t-test Two-sample t-test

lexine
Download Presentation

Practice

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Practice • 10.15 • Did the type of signal effect response time?

  2. t crit (15) = +/- 2.447 • t obs = -2.24 • Fail to reject Ho • The type of signal does not have a significant effect on response time.

  3. New Step • Should add a new page • Determine if • One-sample t-test • Two-sample t-test • If it is a dependent samples design • If it is a independent samples with equal N • If it is a independent samples with unequal N

  4. Thus, there are 4 different kinds of designs • Each design uses slightly different formulas • You should probably make up ONE cook book page (with all 7 steps) for each type of design • Will help keep you from getting confused on a test

  5. “My teacher is an idiot!” • You wonder if the professors at Villanova are more intelligent than the average person. To examine this you collected data from 4 of your teachers. Determine if Villanova professors really have significantly ( = .05) higher IQs than the average IQ of the general population ( = 100).

  6. Data

  7. Step 1: Write out Hypotheses • Alternative hypothesis • H1: Prof > 100 • Null hypothesis • H0:  Prof < or = 100

  8. Step 2: Calculate the Critical t • N = 4 • df = 3 •  = .05 • tcrit = 2.353

  9. Step 3: Draw Critical Region tcrit = 2.353

  10. Step 4: Calculate t observed tobs = (X - ) / Sx

  11. Step 4: Calculate t observed tobs = (X - ) / Sx Sx = S / N

  12. Step 4: Calculate t observed tobs = (X - ) / Sx 14.73=29.45 / 4

  13. Step 4: Calculate t observed tobs = (X - ) / Sx 2.44 = (136 - 100) / 14.73 1.18=14.4 / 150

  14. Step 5: See if tobs falls in the critical region tcrit = 2.353

  15. Step 5: See if tobs falls in the critical region tcrit = 2.353 tobs = 2.44

  16. Step 6: Decision • If tobs falls in the critical region: • Reject H0, and accept H1 • If tobs does not fall in the critical region: • Fail to reject H0

  17. Step 7: Put answer into words • We reject H0 and accept H1. • Professors at Villanova have significantly ( = .05) higher IQs than the average IQ of the general population ( = 100).

  18. Practice • 10.30 • Are surgeons who have been sued more likely to sound dominating than surgeons who have not been sued? • Alpha = .05

  19. t crit (15) = -1.753 • t obs = -2.16 • Accept H1 • Surgeons who sound dominating are more likely to be sued (alpha = .05) than other surgeons.

  20. Practice • Sleep researchers decide to test the impact of REM sleep deprivation on a computerized assembly line task. Subjects are required to participate in two nights of testing. On each night of testing the subject is allowed a total of four hours of sleep. However, on one of the nights, the subject is awakened immediately upon achieving REM sleep. Subjects then took a cognitive test which assessed errors in judgment. Did sleep deprivation lower the subjects cognitive ability?

  21. tobs = 6.175 •  tcrit = 1.83 • Sleep deprivation lowered their cognitive abilities.

More Related