Experimental Exam 2
Home > Flashcards > Print Preview
The flashcards below were created by user
princesspink21
on
FreezingBlue Flashcards. What would you like to do?

Descriptive research:
 to describe the characteristics or behaviors of a given population in a systematic and accurate fashion
 usually a survey

representative sample:
 on from which we can draw accurate, unbiased estimates of the characteristics of the larger population
 we can draw accurate inferences about the population from data obtained from a sample only if it is representative

sampling error:
causes results obtained from the sample to differ from what would have been obtained had the entire population been studied

margin of error:
indicateds the degree to which the data obtained from the sample are expected to deviate from the population as a whole

simple random sampling:
 every possible sample of the desired size has the same chance of being selected from the population
 ex) we want to select a sample of 200 PPTs from a school district that has 5000 students; if we wanted a simple random sample we would select our sample in such a way that every possible combination of 200 students has the same probability of being chosen

stratified random sampling:
 a variation of random sampling
 rather than selecting cases directly from the population, we first divide the population into two or more strata
 ex) the researcher might want to compare younger respondents to older respondents; first stratifying the sample, the researcher ensure that there will be an ample number of both young and old respondents in the sample

convenience sampling:
 researchers use whatever participants are readily available
 ex) sona, most of the psychology studies

What are the 3 measures of central tendency?

what is correlation coefficient?
a statistic that indicates the degree to which two variables are related to one another in a linear fashion

what is the numerical range for correlation coefficient?
1 to +1

What 2 pieces of information are communicated in the correlation coefficient?
 positive or negative relationship
 strength of relationship

coefficient of determination:
 the square of the correlation coefficient
 indicates the proportion of variance in one variable that can be accounted for by the other variable

restricted range:
 a set of data in which PPTs scores are confined to a narrow range of the possible scores
 correlations with restricted range are smaller

outliers:
 scores that are so obviously deviant from the remainder of the data that one can question whether they belong in the data set at all
 they can lead to erroneous conclusions about the strength of the correlation b/w variables

What are the three characteristics that define an experiment?
 1) manipulation of IV
 2) random assignment  researcher must have the power to assign participants to the various experimental conditions in a way to assure their initial equivalence
 3) control for confounds

what are 3 types of IVs (manipulation)?
 environmental manipulations: involve experimental modification of the participants' physical or social environment
 instructional manipulations: vary the variable through verbal instructions that participants reeive
 invasive manipulations: involve creating physical chnages in the participant's body through surgery or the administration of drugs

manipulation check:
a question that is designed to determine whether the IV was manipulated successfully

simple random assignment:
 random assignment of participants to groups
 most basic and important control procedure
 every participant has an equal probability of being placed in any condition
 important because it is a powerful control procedure b/c accounts for all unwanted subject variables

random sample:
taking a random group from a larger group

random assignment:
randomly splitting the sample into groups

matched random assignment:
a procedure for assigning participants to experimental conditions in which participants are first matched into homegeneous blocks and then participants within each block are assigned randomly to conditions

between groups:
 participants assigned to on group (random or matched assignment)
 compare differences in behavior b/w different groups

withinsubject design:
 single group of participants exposed to ever IV level
 eliminated the need for random assignment
 100% sure that PPTs in each group dont differ

What are the stregths of withinsubject design?
 controls for individual differences
 few PPTs are needed
 Instructions may take less time

What are the weaknesses of withinsubject design?
 order effects
 b/c ppts experience all conditions, is easier to figure out the hypothesis

complete counterbalancing:
present every possible order

partial counterbalancing:
choose limited number of orders at random

latin square design:
each condition appears once at each ordianl position

internal validity:
the degree to which a researcher draws accurate conclusions about the effects of the independent variable

attrition:
the loss of ppts during a study

experimenter expectancy effects:
a situation in which a researchers expectations about the outcome of a study influences ppts reactions

demand characteristics:
aspects of a study that indicate to ppts how they are expected to respond

doubleblind procedure:
neither the ppts nor the experimenters who interact with them know which experimental condition a ppt is in at the time the study is conducted

external validitiy:
the degree to which the results obtained in one study can be replicated or generalized to other samples, research settings, and procedures

problems with correlational research:
 restricted range
 outliers
 reliability of measure

problems with causality:
 causality
 reverse causality
 confounds

representative sample:
 means your sample is accurate of the population
 allows accurate, unbiased estimates

internal reliability:
consistency of measures

external reliability
realism to outside world

what is the best way to increase significance?
increase the sample size

sampling frame:
a list of the members of a population

error of estimation
the degree to which data obtained from a sample are expected to deviate from the population as a whole

most correlational research satisfies what criteria for determining causality?
covariation

confederate:
an accomplis of an experimenter whom participants assume to be another participant or bystander

condition:
one level of an IV

confounding:
a condition that exists in experimental research when something other than the IV differs systematically among the experimental conditions