Term
What level(s) of measurement is the frequency distribution designed to describe? 

Definition


Term
In a bar graph the 'bars': 

Definition


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In a histogram the 'bars': 

Definition


Term
What level(s) of measurement is a bar graph designed to describe? 

Definition


Term
What level(s) of measurement is a histogram designed to describe? 

Definition


Term

Definition
bellshaped one peak with two tails right side is mirror image of left 


Term

Definition
2 peaks (set of clusters) 


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Uniform (flat) distribution 

Definition
roughly the same # for every attribute 


Term
What are the measures of central tendency? 

Definition


Term

Definition
"the average" "the value around which all deviations sum to zero" great measure; use it when you can designed for ratio level measures highly influenced by skewness and outliers still mathematically correct but can be misleading 


Term

Definition
• the attribute falling in the middle of a rank ordered set of scores • attribute that falls at the 50th percentile • EX data from 7 people in rank order (odd number) 0,0,1,2,3,7,8 median= attribute at 4th position (2) • EX data from 8 people in rank order (even number 0,0,1,2,3,7,8,10 median=average of 4th & 5th positions • average of 2 and 3= 2.5 median • not as functional as the mean • Not sensitive to outliers/skewness • The variable must be ordinal or ratio (must put attributes in rank order; you cant rank nominal) 


Term

Definition
• simplest measure of central tendency • the attribute that occurs most often (has the highest frequency) NOT how many times it occurs • Not as functional as the median (or mean) • A variable can have more than 1 (bimodal) • Not sensitive to outliers/skewness • The only central tendency measure you can use with nominal data 


Term
what are the measures of variability? 

Definition
range standard deviation variance 


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Definition
o simplest measure o Range=highestlowest o Larger range=more variability Weakness of the range Sensitive to outliers ignored the variability of the scores “in the middle” 


Term
What are the 3 criteria for determining causality? 

Definition
temporal order correlation rule out spuriousness 


Term
What does random assignment mean? 

Definition
Randomly assigned to control group/experimental group 


Term
what do measures of central tendency do? 

Definition
# that tells us where a variables attributes tend to fall 


Term

Definition
make a football fatter
pearson r will be lower (i.e. weaker) b/c of its outlier 


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Definition
make football skinnier
pearson r will be higher (i.e. stronger) b/c of this outlier 


Term
3 rules for using the measures of central tendency 

Definition
1. use mean whenever appropriate ratio data that is normally distributed (or approximately normal)
2. if you cant use the mean, use the median (if appropriate) ordinal data, or ratio data that are highly skewed or have outliers
3. if you cant use the median use mode when you have nominal data 


Term
"double blind" experiments 

Definition
participants dont know what group they are in researcher collecting/analyzing data doesn't know 3rd party knows but doesn't reveal info until data are analyzed 


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statistically significant 

Definition
does not necessarily mean big instead it says the finding is REAL, we believe it exist in our population 


Term

Definition
a table showing the correlation between all possible combinations of variables
univariate analysis/statistics 1 variable bivariate analysis/statistics 2 variables multivariate analysis/statistics 3+ variables 


Term

Definition
is the loss of participants over time due to refusal to participate, inability to reestablish content, death, etc. 

