Ch. 1 Intro to Stats Flashcards
statistics
a set of mathematical procedures for organizing, summarizing, and interpreting information
population
the set of all the individuals of interest in a particular study
sample
a set of individuals selected from a population, usually intended to represent the population in a research study
variable
a characteristic or condition that changes or has different values for diff. individuals
data
(plural) measurements or observations
data set
a collection of measurements or observations
datum
(singular) a single measurement or observation
aka score or raw score
parameter
a value (numerical) that describes a population - derived de measurements of the individuals in the population
statistic
a value, usually a numerical value, that describes a sample
- derived de measurements of the individuals in the sample
descriptive statistics
statistical procedures used to summarize, organize y simplify data
inferential statistics
techniques that allow us to study samples
- make generalizations about the populations from which they were selected
sampling error
naturally occurring discrepancy (error) that exists btwn a sample statistic y the corresponding population parameter
aka margin of error
correlational method
2 different variables are observed to determine whether there is a relationship btwn them
characteristics of an experimental method
(1) manipulation
(2) control
general categories of variables to consider
(1) participant variables
(2) environmental variables
random assignment
each participant has an equal chance of being assigned to each of the treatment conditions
goal: distribute participant characteristics evenly btwn the 2 groups
experimental method
manipulation of one variable while another variable is observed y measured
- establish cause y effect relationship
independent variable
manipulated variable
dependent variable
observed variable
control condition
group that does not receive experimental treatment
- placebo or no treatment
- creates baseline
experimental condition
group that receives experimental treatment
quasi-independent variable
the “independent variable” used to create the diff. groups of scores
constructs
internal attributes or characteristics that cannot be directly observed but are useful for describing y explaining behavior
operational definition
IDs a measurement procedure for measuring an external behav
- use results as definition y measurement of hypothetical construct
discrete variable
consists of separate, indivisible categories
- no values exist btwn 2 neighboring categories
continuous variable
an infinite number of possible values that fall btwn any 2 observed values
- divisible into an infinite number of fractional parts
real limits
boundaries of intervals for scores that are represented on a continuous number line
- separates adjacent scores
upper real limit
at top of interval
lower real limit
at bottom of interval
nominal scale
a set of categories that have different names
- do not make any quantitative distinctions btwn observations
(ie) classifying people by race, gender, or occupation
ordinal scale
a set of categories that are organized in an ordered sequence
- rank observations in terms of size or magnitude
interval scale
ordered categories that are all intervals of exactly the same size
ratio scale
an interval scale w/ the additional feature of an absolute zero point
- ratios of numbers do not reflect ratios of magnitude
