# Shared Flashcard Set

## Details

Psych Exam 2
Psych Exam 2
33
Psychology
10/15/2012

Term
 Sampling frame
Definition
 Physical representation of the population
Term
 Random sampling
Definition
 Equal chance of being chosen; chosen independently; all combos possible
Term
 Sampling Error
Definition
 The difference between a sample stat and a population parameter that's just due to chance. As n increases the sampling error decreases.
Term
 Sampling Distribution
Definition
 normal curve because 0
Term
 Central Limit Theorem
Definition
 The sampling distribution of means will have a mean equal to mu and a standard error equal to sd/sq rt of n. Normal distribution.
Term
 Confidence Intervals
Definition
 We know how much confidence we can place in our estimate and are trying to guess that the mean of the population is within our interval
Term
 level of confidence vs level of precision
Definition
 As one increases the other decreases
Term
 The relationship between a level of conﬁdence, a standard error, and the interval (centered on x-bar) that probably contains μ
Definition
Term
 T-distribution
Definition
 We use the t-table when the standard deviation (o) is unknown.
Term
 Degrees of freedom
Definition
 n-1
Term
 What makes a t-curve different from a normal curve?
Definition
 It uses degrees of freedom
Term
 What is the relationship between confidence and significance?
Definition
Term
 Margin of Error
Definition
 Indirect statement of the width of the confidence interval. plus and minus a number.
Term
 null hypothesis
Definition
 The hypothesis that is tested
Term
 alternative hypothesis
Definition
 a hypothesis that stands in opposition if there is a significant difference among three or more groups of samples.
Term
 alpha level
Definition
 Probability of making a type I error
Term
 extreme score
Definition
 A score that has a low probability of occurrence.
Term
 region of rejection/critical region
Definition
 The test stat (Z) is equal to or falls below the critical value, which in turn allows us to reject the null hypothesis.
Term
 test ratio
Definition
 Number of standard errors away from the mean in the sample. Beginning of the rejection region
Term
 statistical significance
Definition
 compare the critical value to the null hypothesis to determine is something is statistically significant
Term
 Type I error
Definition
 The rejection of the null when it is true. Alpha marks the probabilitity of making a type I error
Term
 Paired sample
Definition
 Sample that involves cases or subjects that share certain characteristics in common.
Term
 Difference score
Definition
 The difference between two population means (mu).
Term
 D bar
Definition
 the mean of the differences between two population means
Term
 mean of the null distribution in a related-sample design
Definition
 zero!
Term
 Independent samples
Definition
 The selection of cases/subjects included in one sample has no connection to or influence on the selection of cases/subjects in the other sample
Term
 Statistic for analysis in n=1 design
Definition
 x
Term
 Statistic for analysis with mu known and a single x bar
Definition
Term
 Statistic for analysis in a related-samples design
Definition
 D bar
Term
 Statistic for analysis in an independent-samples design
Definition
Term
 what is the mu of the null distribution of an independent samples design
Definition
Term
 Standard error of the sampling distribution in an independent samples design
Definition
 that big formula on the formula sheet
Term
 mean difference vs difference of means
Definition
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