Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
76 Cards in this Set
- Front
- Back
population
|
group of events/people a theory applies to
|
|
sample
|
people/events studied
|
|
reliability
|
how much the sample represents the population
|
|
sample size
|
as sample size increases, reliability increases
|
|
experiment
|
intervention, variables to assess
|
|
independent variable
|
manipulated by researcher, controlled
|
|
dependent variable
|
measured by researcher
|
|
random selection
|
equal chance of inclusion makes the experiment unbiased
|
|
parameter
|
characteristics of the population (ex: mean)
|
|
statistic
|
math function computed from data
|
|
descriptive statistic
|
summarizes aspect of data (ex: mean)
|
|
estimator
|
estimates parameter of population
|
|
inferential statistic
|
numerical value without physical meaning
|
|
histogram
|
height of each bar shows number of observations
|
|
discrete variable
|
usually integers, counts-people, classes, etc.
|
|
continuous variable
|
infinite set of values-height, iq, etc.
|
|
nominal scale
|
categories, labels, (no order, no number)
|
|
ordinal scale
|
ordered but no difference between the orders (1st, 2nd, 3rd)
|
|
interval scale
|
numbers, not zero, differences not meaningful
|
|
ratio
|
numbers including zero, differences meaningful
|
|
mean
|
sum of scores divided by number of scores
|
|
median
|
middle value
|
|
mode
|
most common value
|
|
range
|
distance from maximum to minimum
|
|
variance
|
distance from each datum to mean
|
|
standard deviation
|
difference between X and mean
|
|
quantile
|
value of X that is greater than certain part of data
|
|
quartile
|
1st=1/4 of data, 2nd (median), 3rd=3/4 of data
|
|
percentile
|
quantile defined by percentage
|
|
cumulative distribution
|
proportion of scores below or equal to given value
|
|
z score
|
number of standard deviations above or below mean
|
|
standardized distribution
|
distribution of z scores
|
|
expected value
|
mean
|
|
replication
|
doing same experiment with new sample
|
|
sampling distribution
|
probability distribution of some statistic over repeated replication
|
|
central limit theorem
|
distribution of sample mean
|
|
standard error
|
distance from M to Mu
|
|
law of large numbers
|
the larger the sample, the closer M will be to Mu
|
|
hypothesis testing
|
use inferential statistics to choose hypothesis
|
|
null hypothesis
|
no difference in means, means equal 0, nothing interesting in data
|
|
alternate hypothesis
|
there is a difference between the means, something is going on
|
|
type 1 error
|
null is correct but we reject it
|
|
type 2 error
|
null is false but we retain it
|
|
alpha level
|
cutoff for deciding between hypotheses, usually .05
|
|
power
|
if null is false, probability of correctly rejecting it
|
|
critical region
|
range of values that lead to p < alpha (rejecting null)
|
|
critical value
|
boundary of critical region
|
|
binary data
|
only yes/no, right wrong (counts)
|
|
t statistic
|
deviation of sample mean divided by estimated standard error
|
|
t distribution
|
sampling distribution of t statistic
|
|
degrees of freedom
|
tell you how many numbers are really being added
|
|
independent samples t test
|
assumes no relation between sample a and sample b, compare to mann-whitney test
|
|
cohens d
|
standardized effect size
|
|
scatterplot
|
relationship between x and y
|
|
pearson correlation
|
how close 2 variables are related
|
|
independence
|
knowing x tells nothing about y
|
|
linear relationship
|
correlation between x and y
|
|
regression equation
|
y^=b0+b1x1
|
|
intercept
|
value of y when all x's are 0
|
|
f statistic
|
if f is large enough, reject null
|
|
anova
|
analysis of variance, group differences
|
|
grand mean
|
mean of all scores and all groups
|
|
repeated measures anova
|
multiple measures for each subject, like friedman test
|
|
factorial anova
|
multiple independent variables
|
|
goodness of fit
|
deduction of data from prediction
|
|
multinomial test
|
count observations in every category
|
|
expected frequency
|
frequency of each category predicted by null
|
|
marginal frequency
|
total count for each category
|
|
chi square statistic
|
sum of squared z scores
|
|
parametric statistic
|
inferential statistics, assumptions about data
|
|
nonparametric statistics
|
less assumptions, ordinal scale, small sample size
|
|
spearman correlation
|
pearson correlation (ordinal, nonlinear)
|
|
mann-whitney test
|
independent t test, ordinal, small sample
|
|
kruskal wallis test
|
simple anova, ordinal, small sample
|
|
wilcoxon test
|
single/paired t test, ordinal, small sample
|
|
friedman test
|
repeated measures anova, ordinal, small sample
|