# psyc 101

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The flashcards below were created by user gpro on FreezingBlue Flashcards.

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

## Card Set Information

 Author: gpro ID: 148085 Filename: psyc 101 Updated: 2012-04-17 07:06:20 Tags: research psyc Folders: Description: Exam 3 Show Answers:

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