psych col. test 1 ch. 2
Terms
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 correlation coefficient
 a measure of the nature and strength of the relationship between 2 variables
 descriptive statistics
 use mathematical procedures in an objective, uniform way to to describe different aspects of numerical data
 frequency distribution
 a summary of how frequently each of the various scores occurs
 inferential statistics
 use probability and theory to make sound decisions about which results might have occured simply through chance variation
 mean
 the statisic most often used to describe a set of data. the AVERAGE
 measure of central tendancy
 a representative score that can be used as an index of the most typical score obtained by a group of participants
 measures of variability
 statistics that describe the distribution of scores around some measure of central tendancy
 median
 the central score
 mode
 the score that occurs more often than any other
 normal curve
 a bell shaped, symmetrical curve
 range
 the difference between the highest and lowest values in a frequency distribution
 significant difference
 probability that the difference might be due to chance is less than 5 in 100
 standard deviation
 a measure of variability that indicates the average difference between the scores and their mean
 behavioral measures
 ways to study overt actions and observable and recordable reactions
 betweensubject designs
 randomly assigned groups to either experimental or control conditions
 case study
 study of one individual or a small group
 confounding variable
 something which is not purposely introduced into an experiment, and changes a participants behavior and adds confusion to interpretation of the data
 control procedures
 methods that attempt to hold constant all variables and conditions other than those related to the hypothesis being tested
 correlational methods
 used to determine to what extent 2 variables , traits, or attributes are related.
 positive correlation
 +1 : as one set of scores increases, so does the other
 negative correlation
 1 :if one set of scores increases, the other decreases
 no correlation
 0.0 : scores closer to zero mean there is weak or no realtionship between the scores
 debriefing
 the researcher provides as much information about the study as possible, and makes sure that no one leave feeling upset, confused, or embarrassed
 dependant variable
 what the experimentor measures
 determinism
 all events physical, mental, and behavioral, are the result of, or determined by, specific casual factors
 doubleblind control
 both experimentors and subjects are unaware of which participants get which treatment
 expectancy effects
 whena researcher subtly communicated to the subjects the behaviors they expect to find, producing their dsired reaction
 experimental methods
 maipulating an independant variable to look for an effect on a dependant variable
 independant variable
 the factor that the researcher manipulates
 observer bias
 an error due to the personal motives and expectations of the veiwer
 operational definition
 standardizes meaning within an experiment , by defining a concept in terms of certain procedures used to measure it or define its prescence
 placebo control
 administering placebos
 placebo effect
 occurs when experimental participants change their behavior in the abscence of any experimental manipulation
 reliability
 the consistency or dependability of behavioral data resulting from psycological testing
 representative sample
 a representative sample of a population if it matches the overall characteristics of that population
 sample
 small sample of population
 scientific method
 a general set of procedures for gathering and interpreting evidence in ways that limit errors and provide dependable conclusions
 selfreport measures
 verbal answers, either written or spoken, to questions the researcher poses
 standarization
 using unifrom, consistent procedures in all phases of data collection
 theory
 an organized set of concepts that explain a phenomenon
 validity
 the info. produced by research accurately measures the psychological quaility it's intended to
 variable
 any factor that varies in amount or kind
 withinsubjects design

uses each participant as his or her own control
ex: infant changing emotion based on facial expression