EXAM 1 Flashcards
Statistics
the science of collecting, classifying, presenting, and interpreting data
Data
the collection of numerical observations in a sample
Data Analysis
the application of mathematical principles to events in the empirical world
Measurement
the assignment of numbers to represent different levels or amounts of a variable
What are the four scales of measurement?
nominal, ordinal, interval, and ratio
Nominal measurement
code, classify, and categorize our data
Ordinal measurement
rank orders the data
Interval measurement
equal units of measurement
Ratio measurement
true 0 point
Relative frequency
a proportion. proportion of subjects who had a specific core value
Cumulative frequency
number of students who scored at or less than a specific score value
Relative cumulative frequency
cumulative frequency divided by the sample size
Descriptive Statistics include __________?
Frequency distributions, measures of central tendency, and measures of variability
Measures of variability include ___________?
The range, Interquartile Range, and the variance
What does it mean if a distribution of scores is HOMOGENOUS?
the scores vary just a little
What does it mean if a distribution of scores is HETEROGENOUS?
the scores vary a lot
Range
used with nominal or ordinal data; largest score (-) the smallest score
Interquartile Range - IQR
divides the distribution into 4 equal sections “quartiles”. then we find the range for the “inner” two quartiles
(P75 - P25)
Variance
how much do the scores deviate from each other?
What are the types of variables?
dependent, and independent variables
Dependent variables
variable that is measured
Independent variables
variable that is manipulated. this variable causes change in the dependent variable
The manipulation of independent variables is based on what?
Quality (levels differ in type), quantity (levels differ in amount), and presence/absence of IV (whether it is given or not)
Between subjects/groups
each group of subjects receive only ONE level of the independent variable
Within subjects/groups
each group of subjects receive ALL levels of the independent variable
