ch2 Flashcards
positive skew
graph with mostly low scores, few high scores
negative skew
graph mostly high scores, with a few low ones.
measures of variability
range, standard deviation, variance
z-score
how far away a score is from the mean score. (measured in standard deviations)
used when comparing results from different graphs/studies
normal curve
bell shaped curve with predetermined area
inferential statistics
determines whether or not a study’s findings can be applied to a larger population
correlation coefficient
how strong or weak the relationship between 2 things are. 0 means no relation
correlation
expresses a relationship between two variables without considering that one was caused by another
positive correlation
(+1) how much something predicts another thing
negative correlation
(-1) how much something predicts the absence of something
scatter plot
graph with random points (results) scattered across
line of best fit/ regression line
a line that is minimal distance from all points
p value
probability of results being caused by chance (minimum 0.05 to be considered statistically significant)
statistical significance
how accurate something is (minimum 0.05)
International Review Board (IRB)
ethics board, responsible for approving any potential studies.
coercion
bribing/blackmailing someone into participating in the study
informed consent
telling participants what they are consenting to
anonymity
participant identities will not be published
confidentiality
participants may not anonymous, but results will not be connected to any participants.
debriefing
occurs at the end, where participants are informed about what the experiment was about, and how to reach out to get results.
hindsight bias
when people hear something new and believe that they knew it all along
applied research
research with clear practical applications
basic research
research that targets an area of interest with no immediate real world applications
hypothesis
expresses a relationship between two variables (predicts what will happen)
variable
things that can vary among participants
independent variables
variables that aren’t affected by other variables
dependant variable
variables that can change depending on the independent variables
theory
potential explanation to certain phenomenon
operationalizing variables
how variables will be measured/considered (ex. at what point will a video game be considered violent)
reliability
research is reliable if it can be replicated
validity
research is valid if its accurate and measures what the researcher set out to measure
sampling
picking out participants for an experiment
sample
used in research to represent a larger population
random sampling
equal chances for everyone; ex. computer generation, table of random numbers, etc.
stratified sampling
random sampling but it’s proportional to the population. the population is divided based off certain criteria (race, height, gender, etc) before random sampling.
representative sampling
sample of a larger group that accurately represents the characteristics of the larger group
laboratory experiments
conducted in lab/highly controlled environment. causal relationships can be shown here
field experiments
conducted in real world
causal relationships
when one thing directly causes another thing (cause-effect relationship)
confounding variables
any variables that can affect both independent and dependant variables. can cause error in experiments, and make it difficult to see causal relationships
participant relevant confounding variables
any characteristics of participants that may skew results
random assignment
method of assigning participants to control & experimental groups as to prevent preexisting characteristics of participants affecting experiment.
group matching
organizing groups based off certain criteria (age, sex, height, gender, etc.)
experimenter bias
when the experimenter unconsciously treats the two groups differently in order to increase chances of a hypothesis being true
double blind procedure
when neither the experimenter or participant can significantly affect results
single blind procedure
where participants don’t know which group they have been assigned to
demand characteristics
cues about the purpose of the experiment that can affect participants response
response/participants/subject bias
a tendency for participants to respond in certain ways
social desirability
type of response bias, is a tendency to pick/give answers that reflect well upon them
experiment group
affected by independent variable
control group
not affected by independent variable
Hawthorne effect
people act in certain ways just because they know they are in an experiment
placebo effect
when participants display symptoms of certain substances after taking a fake substance; the symptoms are caused by expectations alone
counterbalancing
used to prevent order effects: using participants as their own control group
order effects
doing something better just because the participant has done it more than once
survey method
asking people to fill out surveys. no dependant or independent variables, and variables cannot be manipulated. But, participants relevant confounding variables can no longer be controlled.N
aturalistic ovservation
observing participants in their natural habitat without any interaction.
case studies
detailed report on one or a small group of individuals. cannot be generalized. (usually used for info about a specific disorder.
descriptive statistics
summarizes information, describes a set of data
frequency distribution can be turned to…
histograms (bar graphs or (frequency polygons (line graph)
Mean
average of all scores
median
center score (middle score when all scores are arranged in a line)
mode
score that appears most frequently
extreme scores/outliers
a score (or group of scores) that is significantly above/below average. Can skew graphs
symmetrical distribution
graph with no major skews
range
distance between highest & lowest scores in a distribution
variance
measurement of how far each number from a graph is from average (mean)
standard deviation
how spread out the data in a graph is in relation to the mean. calculated as (square root of variance)
low standard deviation means data points are clustered together, high standard deviation means data is more spread out.
