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Marks Stats Final
Stats final for my co-glorious cohort and I
67
Psychology
Graduate
12/04/2012

Additional Psychology Flashcards

 


 

Cards

Term
Correlation definition
Definition
measurement of the relationship or association between variables
Term
correlation: levels of measurement
Definition
2 continuous or 1 continuous, 1 dichotomous categorical; MUST be equal interval
Term
correlation: research question
Definition
do individuals who have a low/high score on 1 variable also have a corresponding low/high score on another variable? for each unit change in X, is there a corresponding unit change in Y? how strong is the relationship between these two variables?
Term
correlation: assumptions
Definition
normality, linearity (HIGHLY susceptible to outliers), equal interval variables, independence of observations,
Term
correlation: 2 types
Definition
bivariate (2 variables, measured with Pearson's product-moment correlation R, or Spearman's rho for ordinal/high outlier data) or partial (explore relationship b/t 2 variables while statistically controlling for a third)
Term
benefits of partial correlation
Definition
provides a more clear, accurate depiction of actual relationship between 2 variables
Term
example of correlation write up
Definition
Results shows a strong, positive correlation between posting stats shit on Facebook and being a total dork (r = .88, p < .01). This relationship remained significant, even after controlling for number of hours spent drooling over David Klonsky's LCA paper ( r = .66, p < .01).
Term
correlation: measurement (2)
Definition
strength/ magnitude (how spread are data around line of best fit? tight or loose?)
direction (+ or -) low~ low, high~high, low~high, high~low
Term
correlation coefficient
Definition
calculated using z-scores (need z's because of different scales, with different means and SDs) cross products= zscore of x X zscore of y = avg of cross products= R
Term
Pearson's correlation (r)
Definition
correlation coefficient r= regression, sum of cross products of the z scores/ n = + - 1
Term
Spearman's rho
Definition
correlation coefficient when using ordinal data or highly skewed (lots of outlier) data
Term
small, medium, large correlations
Definition
.1-2.9, .3-.49, .5 and up
Term
2 methods to test for outliers
Definition
histogram (univariate)
scatterplot (multivariate)
Term
reliability
Definition
consistency, stability of a measure. necessary but not sufficient for validity of the measure
Term
validity
Definition
degree to which an instrument measures the construct intended, accuracy
Term
small, medium, large measure of reliability
Definition
.45-.65 shitty
.70-.80 acceptable
>.80 optimal
.99= measuring same thing? context needed
Term
frequency scales
Definition
Likert, how often behavior or event has occured, opinion as to how strong a person feels about something. Assume linear relationship. neutral point? can use as interval data to use parametric tests. need normality of distribution for certain tests.
Term
Thurstone scales
Definition
empirical data from judges to ensure attitudes/behaviors being measured are spaced along continuum of equal rating
Term
guttman scaling
Definition
hierarchical scaling technique that ranks items such that individuals who agree with higher ranked item will also agree with items of lower rank
Term
piloting a measure
Definition
should be done w a smaller sample, but large enough to allow for a cronbach's alpha greater than .70, determine which items should be kept/deleted
Term
factor analysis
Definition
extraction, principal component analysis, varimax/oblimination rotation
Term
PCA
Definition
principal component analysis- explores relationship between variables, provides basis for removal of uncessary items and ID subscales/domains
Term
varimax/oblimin rotation
Definition
factor rotation that maximized loadings of variables on different subscales. varimax with correlated. Oblimin with uncorrelated. ID number of domains in measure
Term
construct validity
Definition
degree to which an instrument is related to operationally defined theory and concepts
Term
construct validity:measurements
Definition
contrasted groups- 2 groups high and low known, means should differ
hypothesis testing- theoretical
factor analysis- related items kept, exploratory and confirmatory
Term
convergent/discriminant validity: measurements
Definition
multitrait- multimethod approach- MTMM 2 more constructs with 2 more methods, correlation matrix for relationships between traits
Term
translational validity
Definition
face and content validity-
Term
content validity
Definition
items measure the complete range of the attribute under study (i.e. not 4 types of NSSI, but 14) determined by lit review, experts, population sampling, largest pooling then reduced with factor analysis
Term
face validity
Definition
instrument looks like it measures the construct of interest, subjective,
Term
criterion validity (4 types)
Definition
concurrent, predictive, convergent, discriminant; relationship between measurement and construct based on performance on another variable
Term
concurrent validity
Definition
scores on a measure correlated to a related criterion at the same point in time
Term
concurrent validity: measurements
Definition
exploratory factor analysis, eigen >1; confirmatory factor analysis, loading on each subscale >,4; principal components analysis ( 5 pps per variable) ex. ISAS and SITBI
Term
predictive validity
Definition
degree to which scores predict performance on some future criterion
Term
predictive validity: measurements
Definition
correlations, regressions
ex. ISAS behavioral forecast predicts NSSI
Term
convergent validity
Definition
correspondence between constructs that are theoretically similar.
Term
convergent validity: measurements
Definition
correlations. ex ISAS and MSI-BPD
Term
discriminant validity
Definition
measurement differentiates between constructs that are theoretically different
Term
discriminant validity: measurements
Definition
MT-MTT, weak/no correlation. ex ISAS and SITBI gesture, suicide attempt
Term
content validity: measurements
Definition
content validity ration (CVR) or content validity intex (CVI) depend on number of experts (+7)
Term
test-retest reliability
Definition
similar scores at different times, 2 weeks-1 month, not due to chance, some states do change, so not useful
Term
internal consistency
Definition
cronbach's alpha. inter-item correlations to determine if items measure some construct. how well they "hang" together. can add items to increase. if over .9 might be measuring same thing
Term
parralel/ alternate forms of reliability
Definition
different items pool to test same concepts, ie day and night measure.
Term
Magnusson quote as to why we need good measures
Definition
"models are never more accurate, reliable, or valid than the measures you put into them"
Term
regression definition
Definition
use correlations in a systematic/meaningful way to test hypotheses. predict/ calculate any value of y (DV) from a value of x (IV). based on probabilities
Term
variance in regression
Definition
R squared multiple correlation. how much of DV's variance is accounted for by the IV. 0-1. always positive. closer to 1= greater amount of variance explained. tests magnitude of prediction and mediation.
Term
y= Bo + B1 (x) + err
Definition
y= DV
Bo= intercept, constant
B1= slope/ beta weight/ regression weight
X= value of IV
err= random, unsystematic error
USE UNSTANDARDIZED SCORES
Term
assumptions of regressions
Definition
linearity/normality, independence and homogeneity of error, heteroscedasticity- variability at one point is similar to variability at different point.
Term
uni vs multi regressions
Definition
predict DV from IV OR >1 IV from 1 DV (mediation)
Term
leverage
Definition
how far case is from other cases
Term
discrepancy
Definition
how in line with linear trend
Term
regressions standardized coefficients
Definition
interpreted as correlation strength, direction, significance.
Term
collinearity
Definition
measures are overly related, may be measuring same thing. everything is significant when testing reliablity
Term
variable centered approach
Definition
given prior behavior, scores, genetic markers, contextual risk and protective factors, individuals are interchangeable units who apart from random error, do not differ qualitatively or quantitatively from each other.
Term
person centered approach
Definition
how individuals change or behave. how individuals function, holistic. do not assume normality, less sensitive than parametric tests and may fail to detect differences that actually exist (type I error)
Term
synchronization
Definition
developmental processes are active, integrated, complex, dynamic, adaptive in relation to greater system
Term
ecological fallacy
Definition
drawing false conclusions about individual behavior from population behavior
Term
atomistic fallacy
Definition
drawing false conclusions about aggregate behavior from individuals
Term
types of person centered analyses
Definition
classification (cluster and LCA)
hybrid classification (growth mix model)
single-subject methods (dynamic factor analysis)
variable oriented methods: latent growth curve modeling
Term
cluster analysis
Definition
examine how groups of individuals are similar to one another, and different from individuals in other groups/clusters. exploratory in nature
Term
hierarchical cluster analysis
Definition
small >50 data sets standardized continuous data
Term
K-means cluster analysis
Definition
moderate sample size, standardized continuous data, assign cluster then recheck means to maximize differences b/t groups. may or may not ask SPSS to create a specific number of groups
Term
2 step cluster analysis
Definition
large data sets, computer selects number of clusters based on most relevant variables, maximize differences bt clusters, can use continuous, discrete nominal data. step 1= preclustering put new in with preclusters or make a new one.
step 2= use hierarchical techniques to make two clusters then assign to clusters
Term
BIC
Definition
Shwarz's Bayesian ID criterion; change of more than one= best number of clusters
exactly how much more likely it is to get an individual from group a vs group b
Term
2 ways of clustering
Definition
log likelihood estimates (MLE or LSE) with mix of variable types
Euclidian distance same standardized variables
Term
latent class analysis
Definition
ID unique classes of cases like cluster analysis with categorical data. estimation uses MLE. assumes variables are uncorrelated within classes, although often not the case
Term
latent variable analysis
Definition
determine latent variables (ones that cannot be measured directly)- circles based on observed/ indicator variables- boxes. need 4
Term
example of regression write up
Definition
Time spent oogling over David Klonsky's LCA is predictive of desire to TA stats for smelly undergrads, such that more time spent oogling was significantly positively associated with desire to TA smelly undergrads (r = .66, p < .01). Time spent oogling explained 80% of the variance in desire to TA smelly undergrads.
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