Statistics and Research Flashcards
Alpha (level of power)
Alpha determines the probability of rejecting null hypothesis when it is true. The value of alpha is set by the researcher before collecting or analyzing data. Usually .01 or .05
ANCOVA (Analysis of covariance)
The analysis of covariance is a version of the ANOVA that is used to increase the efficiency of the analysis by statistically removing variability in the DV that is due to an extraneous variable. When using the ANCOVA, each person’s score on the DV is adjusted on the basis of his score on the extraneous variable.
Between-Groups Designs
are experimental research designs that allow a researcher to assess the effects of the different levels of one or more IVs by administering each level or combination of levels to a different group of subjects.
Between-Groups Designs
are experimental research designs that allow a researcher to assess the effects of the different levels of one or more IVs by administering each level or combination of levels to a different group of subjects.
Central Limit Theorem
derived from the probability theory and predicts that the sampling distribution of the mean (a) will approach a normal shape as the sample size increases, regardless of the shape of the population distribution of scores, (b) has a mean equal to the population mean, (c) has the standard deviation equal to the deviation referred to as the standard error of the mean.
Central Limit Theorem
derived from the probability theory and predicts that the sampling distribution of the mean (a) will approach a normal shape as the sample size increases, regardless of the shape of the population distribution of scores, (b) has a mean equal to the population mean, (c) has the standard deviation equal to the deviation referred to as the standard error of the mean.
CHI-SQUARE TEST (Single/Multi Sample)
is a nonparametric statistical test that is used with nominal data. It is a goodness of fit type of test. (O bserved - E xpected)squared divided by E xpected. The answer minus 1 gives degrees of freedom. Standard acceptance of Null Hyp starts after .05
CHI-SQUARE TEST (Single/Multi Sample)
is a nonparametric statistical test that is used with nominal data. It is a goodness of fit type of test. (O bserved - E xpected)squared divided by E xpected. The answer minus 1 gives degrees of freedom. Standard acceptance of Null Hyp starts after .05
Cluster Analysis
is a multivariate technique used to group people or objects into a smaller number of mutually exclusive and exhaustive subgroups (clusters) based on their similarities.
Cross-validation / Shrinkage
refers to validating a correlation coefficient on a new sample. The correlation coefficient tends to shrink on cross-validation. Shrinkage is greatest when the original sample size is small and the number of predictors is large.
Discriminant Function Analysis
is the appropriate multivariate technique when 2 or more continuos predictors will be used to predict or estimate a person’s status on a single discrete (nominal) criterion.
Effect Size
is the measure of magnitude of the relationship between the dependent and independent variables; useful for interpreting the relationship’s clinical or practical significance. Use Cohen’s d (difference between groups in standard deviations) or eta squared (percent of variance in DV accounted for by variance in the IV)
Experimental Research (Quasi & True)
conducting an empirical study to test hypothesis about relationships. TRUE experiments hallmark is random assignment into groups.
Experimental Research (Quasi & True)
conducting an empirical study to test hypothesis about relationships. TRUE experiments hallmark is random assignment into groups.
Experimentwise Error Rate
The prob of making a type I error. As the number of statistical comparisons increases so does the EER.
External Validity
The degree to which a study’s results can be generalized to other people, settings and conditions. Threats include: pretest sensitization, multiple-treatment interference,
Factorial ANOVA (2-way, 3-WAY ANOVA)
appropriate when study includes 2 or more IVs and a single DV.
Internal Validity
Is it a causal relationship? Are we measuring what we say we are measuring?
Internal Validity
Is it a causal relationship? Are we measuring what we say we are measuring?