Stats.txt

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

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

• validity is almost entirely dependent on reliability
• both are necessary

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

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

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

practice of relying on observation and experimentation

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

observations made in natural or native settings

an educated guess

the manipulated variable

the variable whose reaction is being observed

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

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

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

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

anything the researcher does that interferes w/ the experimental design

subjects are not aware of which group they're in

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

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

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

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

experimental design looking at two or more independent variables

number of variables

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

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

• less than 30 subjects;
• results are less generalizable;
• often used in drug trials

a detailed, non-experimental analysis of a person or group

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

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

some other variable(s) that affects the results

a model or pattern an investigator uses to organize research

• two separate groups: experimental and control;
• each subject is in one condition

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

all subjects are exposed to all conditions, all subjects are their own control

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

participants are assigned by chance to 1 of 2+ conditions

matching a sample as best you can

using matching techniques to try to equate groups on important characteristics

• counterbalancing procedure;
• each condition occurs equally often
• (1,2,3,4; 2,3,4,1)

improvement over multiple trials

when subjects become bored or tired and their performance decreases

loss of participants over a long period of time

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

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

a precise statement of the knowledge that was gained

a characteristic that varies between individuals

observation made on a variable

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

collection of subjects we select as representative of the population

the group of subjects to whom the research applies

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

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

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

number of participants in a study

subject

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

• qualitative scale;
• labels used to differentiate observations

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

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

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

collection of measurements viewed in terms of the frequency of observations

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

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

indexes that refer to how scores tend to cluster in a particular distribution

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

the midpoint or midscore in a distribution

the most frequent score in a distribution

• indexes that describe the dispersion or scatter across the measurement scale;
• range, variance, & standard deviation

the highest score in a distribution minus the lowest score

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

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

characteristic of a sample

characteristic of a population

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

the standard deviation of a distribution of sample means

inferred by the mean of the sample

a statement/assumption of no difference

a statement/assumption of a statistically significant difference

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

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

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

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

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

variance between groups / variance within groups

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

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

whatever nonerror variation is observed among the individual group when the main-effects variation has been removed

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

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