psyc 101

Card Set Information

Author:
gpro
ID:
148085
Filename:
psyc 101
Updated:
2012-04-17 03:06:20
Tags:
research psyc
Folders:

Description:
Exam 3
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user gpro on FreezingBlue Flashcards. What would you like to do?


  1. sampling distribution
    a distribution of statistics obtained by selecting all possible samples of a specific size from a population
  2. the power of a test
    • the probability that the test will correctly reject a false null hypothesis
    • 􏰄 It will detect a treatment effect if one exists
    • 􏰄Power=1–β or1–p(TypeIIerror)
  3. Influences on power
    • 􏰀 Treatment effect --> more effect more power
    • 􏰀 Alpha level --> larger alpha more power
    • 􏰀Two-tailedvs.one-tailedtest -->one-tailed more power
    • 􏰀Sample size -->larger and more power
  4. z test for one sample
    • 􏰀 Used when the untreated population’s
    • μ and σ are given
    • 􏰀 The z statistic equation
    • 􏰀 Effect size
    • d= M - μ / σ
  5. t test for one sample
    • 􏰀 Used when the untreated population’s μ is given but no σ
    • 􏰀 The t statistic equation
    • 􏰀 Effect size
    • ̂d=M-μ /s
  6. Steps for t test
    • 1) set hypothesis
    • 2) set criteria
    • 3) calculate statistics
    • - sample variance
    • - sample standard deviation
    • - estimated standard error
    • - standard error
    • - t statistic
    • 4) make a decision
    • 5) Assess effect size
    • 6) report results
  7. Effect Sizes
    • d= 0.2 (small effect)
    • d= 0.5 (medium effect)
    • d= 0.8 (large effect)
  8. Independent Samples t-test
    • 􏰀 Between subjects design
    • 􏰄 Simple experiment
    • 􏰄 Simple quasi-experiment
    • 􏰄 No matched groups!
    • 􏰄 H0 : μ2 – μ1 ≤ 0
    • 􏰄 H1: μ2 – μ1 > 0
  9. Assumptions of independent measures t-test
    • - Groups are independent
    • - The two populations are normally distributed
    • - Homogeneity of variances
    • 􏰂 σ1 squared =σ2 squared
  10. effect size
    A measure of this is intended to provide a measurement of the absolute magnitude of a treatment effect, independent of the size of the sample(s) being used.
  11. Power
    The probability that the test will correctly reject a false null hypothesis. That is, power is the probability that the test will identify a treatment effect if one really exists.
  12. t distribution
    The complete set of t values computed for every possible random sample for a specific sample size (n) or a specific degrees of freedom (df). The t distribution approximates the shape of a normal distribution.
  13. Estimated Cohen's d
    The estimate of the effect size when we don’t know the standard deviation of the population (we’ll use S instead)
  14. independent-measures/between-subjects study
    • - uses a seperate sample to represent each of the populations or treatment conditions being compared
    • --> pooled variance

What would you like to do?

Home > Flashcards > Print Preview