
reliability
 degree to which the measure will generate the same result in the same condition
 consistency of an experiment or test

validity
 degree to which we measure what we purport to measure
 the factual accuracy of an observation

reliability vs. validity
 validity is almost entirely dependent on reliability
 both are necessary

scientific method
 1) statement/hypothesis;
 2) observations;
 3) replicability;
 4) model/law

order
 processes are not random;
 they happen in a recognized pattern or sequence

determinism
 all events have a cause;
 psychological phenomena have antecedents, or preceeding circumstances that cause an event

empiricism
practice of relying on observation and experimentation

parsimony
 the simplest answer is usually the right one;
 good if supported by data

naturalistic observation
observations made in natural or native settings

hypothesis
an educated guess

independendent variable
the manipulated variable

dependent variable
the variable whose reaction is being observed

experimental group
group that receives the experimental treatment (some manipulation by the experimenter)

control group
treated exactly like the experimental group except they do not receive the experimental treatment

primacy
tendency to remember things better when they come first in a series

recency
tendency to remember things better when they come last in a series

experimental bias
anything the researcher does that interferes w/ the experimental design

singleblind study
subjects are not aware of which group they're in

doubleblind study
 both judges and subjects are unaware of what group the subjects are in;
 often used in drug research or anything involving subjective judging

within subject design
participants are both the control and the experimental groups (all subjects are in all conditions)

demand characteristics
environmental cues that lead to a subject/participant to respond a particular way (either subtle or not subtle) because they know what the researcher is looking for

correlational studies
 studies of the relationship between two variables;
 does not establish causality!

factorial design
experimental design looking at two or more independent variables

main effect
number of variables

interaction effect
 when the effect of 1 variable is not the same at each level of the other variable.
 (intersect=interaction; no intersect=no interaction)

quasiexperimental design
still have experimental and control groups, but no random assignment w/ an open system

small "n" research
 less than 30 subjects;
 results are less generalizable;
 often used in drug trials

case study
a detailed, nonexperimental analysis of a person or group

generalization
the extent to which a finding applies to persons other than those that were the subject of the study

controls
must account for other factors by holding for other conditions and subject variables constant

confounds
some other variable(s) that affects the results

paradigms
a model or pattern an investigator uses to organize research

between group design
 two separate groups: experimental and control;
 each subject is in one condition

matched subject design
when a subject variable is so critical in the experiment, subjects are matched on that variable

repeated measures design
all subjects are exposed to all conditions, all subjects are their own control

placebo design
two control groups are used, w/ one receiving a "placebo" version of the treatment

randomization
participants are assigned by chance to 1 of 2+ conditions

adlib matching
matching a sample as best you can

random block design
using matching techniques to try to equate groups on important characteristics

latin square design
 counterbalancing procedure;
 each condition occurs equally often
 (1,2,3,4; 2,3,4,1)

practice effect
improvement over multiple trials

fatigue effect
when subjects become bored or tired and their performance decreases

attrition
loss of participants over a long period of time

problem statement
a precise statement of what knowledge is sought and why it was sought

method
 the plan of the research;
 how the knowledge was gained

results
a precise statement of the knowledge that was gained

variable
a characteristic that varies between individuals

data
observation made on a variable

measurement
a scheme for the assignment of numbers or symbols to specify different characteristics of a variable

sample
collection of subjects we select as representative of the population

population
the group of subjects to whom the research applies

descriptive statistics
summary descriptors or characteristics of the population/sample (mean, median, & mode)

descriptive research
a research plan undertaken to define the characteristics and/or relationship among variables based on systematic observation of these variables

experimental research
a research plan undertaken to test relationships among variables based on systemic observation of variables that are manipulated by the researcher

"n"
number of participants in a study


scale
a specific scheme for assigning numbers or symbols to designate characteristics of a variable

nominal scale
 qualitative scale;
 labels used to differentiate observations

ordinal scale
 scale that implies an order (ascending or descending);
 ranked, not w/ set intervals

interval scale
 scale w/ equality between units;
 has an arbitrarily assigned zero points;
 can only do +, & 

ratio scale
 scale w/ equality between units;
 has an absolute zero points;
 can do +, , *, & /

distribution
collection of measurements viewed in terms of the frequency of observations

frequency
 way to organize data;
 can simplify w/ a graph

bell curve
 the shape of a "normal" distribution;
 mean of 100, standard distribution of 15;
 mean=median=mode

measures of central tendency
indexes that refer to how scores tend to cluster in a particular distribution

mean
 the sum of the scores in a distribution divided by the number of scores
 (aka the average)

median
the midpoint or midscore in a distribution

mode
the most frequent score in a distribution

indices of dispersion/measures of variability
 indexes that describe the dispersion or scatter across the measurement scale;
 range, variance, & standard deviation

range
the highest score in a distribution minus the lowest score

variance
the mean of the squared deviation scores about the mean of a distribution

standard deviation
 the square root of the mean of the squared deviation scores about the mean of a distribution
 (or, the square root of the variance)

statistic
characteristic of a sample

parameter
characteristic of a population

normal distribution
definition of a particular functional relation between deviations about the mean of a distribution and the probability of these different deviations occuring

standard error of the mean
the standard deviation of a distribution of sample means

population mean
inferred by the mean of the sample

null hypothesis
a statement/assumption of no difference

research hypothesis
a statement/assumption of a statistically significant difference

significance
the level of calculated probability was sufficiently low as to serve as grounds for rejection of the null hypothesis

1tailed test
a directional hypothesis test that incorporates a rejection region in only one tail of the probability curve used for a given statistic

2tailed test
a nondirectional hypothesis test that incorporates rejection regions in both tails of the probability curve used for a given statistic

ttest
used to calculate the probability of whether a particular difference between sample means would be expected under the terms of the null hypothesis

ANOVA
 used when there are 3+ values to compare;
 shows if there is a difference somewhere in the values

Fratio
variance between groups / variance within groups

multivariate analysis
statistical model for testing the influence on multiple dependent variables in a single research design

multifactor analysis
statistical model for testing the consequences of manipulating 2+ independent variables in a single research design

interaction effect
whatever nonerror variation is observed among the individual group when the maineffects variation has been removed

nonparametric statistics
 used in small "n" research;
 when descriptive alone is ok

Chisquared
 compares an observable set of frequency with an expected set of frequency;
 can be used to detect bias

