chapter 2 Flashcards
empiricism
the conviction that accurate knowledge of the world can be acquired through observing it
scientific method
a procedure for using empirical evidence to establish facts
theory
an explanation of a natural phenomenon
hypothesis
a falsifiable prediction made by a theory
empirical method
a set of rules and techniques for observation
operational definition
a description of a property in measurable terms
construct validity
a feature of operational definition whose specified operations are generally considered good indicators of the specified properties
power
a detector’s ability to detect the presence of differences or changes in the magnitude of a property
demand characteristic
those aspects of an observational setting that cause people to behave as they think someone else wants or expects
observer bias
the tendency for observers’ expectations to influence both what they believe they observed and what they actually observed
double blind study
a study in which neither the researcher nor the participant knows how the participants are expected to behave
population
a complete collection of people
sample
a partial collection of people drawn from a population
frequency distribution
a graphic representation showing the number of times that the measurement of a property takes on each of its values
normal distribution
a mathematically defined distribution in which the frequency of measurements is highest in the middle and decreases symmetrically in both directions
mode
the value of the most frequently observed measurement
mean
the average value of all measurements
median
the value that is in the middle when the measurements are arranged from least to greatest
range
the value of the largest measurement in a frequency distribution minus the value of the smallest measurement
standard deviation
a statistic that describes how each of the measurements in a frequency distribution differ from the mean
variable
a property that can have more than one value
correlation
a relationship between variables in which variations in the value of one variable are synchronized with the variations in the value of the other
correlation coefficient (r)
a mathematical measure of both the direction and strength of a correlation. which is symbolized by the letter r. the closer to +1 or -1 = stronger the correlation.
natural correlation
a correlation that is observed in the natural world
third variable problem
the fact that the natural correlation between two variables cannot be taken as evidence of a casual relationship between them because a third variable might be causing them both
experimentation
a technique for establishing the casual relationship between variables
manipulation
a technique for determining the casual power of a variable by actively changing its value
independent variable
the variable that is manipulated in the experiment. (cause)
dependent variable
the variable that is measured in an experiment. (effect)
self selection
a problem that occurs when anything about a participant determines the value of the independent variable to which the participant was exposed
random assignment
a procedure that assigns participants to conditions by chance
internal validity
an attribute of an experiment that allows it to establish casual relationships
external validity
an attribute of an experiment in which variables have been operationally defined in a representative way
case method
a procedure for gathering scientific information by studying a single individual
random sampling
a technique for selecting participants that ensures that every member of a population has an equal chance of being included in the sample
replication
an experiment that uses the same procedures as a previous experiment but with a new sample from the same population
type I error
an error that occurs when researchers conclude that there is a casual relationship between two variables when there is in fact not
type II error
an error that occurs when researchers conclude that there is no casual relationship between two variables when there in fact is
informed consent
a verbal agreement to participate in a study made by an adult who has been informed of all the risks that participation may entail
debriefing
a verbal description of the true nature of a study
fact
an objective statement, usually based on direct observation , that reasonable observers agree is true
law of parsimony
if 2 theories can explain and predict the same phenomenon equally well, the simpler theory is preferred
self report measures
those that ask people to report their own knowledge , beliefs, feelings, experiences, etc.
behavioral observation
psychologists may use occurrence, frequency, or timing of a behavioral occurrence
naturalistic observation
research where behavior is observed as it occurs in a natural setting
survey research
research involving the collecting of info about a topic by administering questionnaires / interviewing people
correlational research
a research design in which the researcher examines the relationship between 2 or more variables
positive correlation
as the value of one variable increases, so does the other
negative correlation
as the value of one variable increases, the other decreases.
covariance
as the independent variable changes, so does the dependent variable
temporal precedence
the manipulation ( independent variable) occurs before the measurement (dependent variable)
experiment / treatment group
group that receives treatment or an active level of independent variable
control group
group not exposed to treatment or independent variable and is used as a comparison group
reliability
the tendency for a measure to produce the same result whenever it is used to measure the same thing
test retest reliability
when the assessment is consistent at different points in time
interrater reliability
when assessments from different researchers are consistent
internal reliability
when items within an assessment are consistent
validity
the characteristic of an observation that allows one to draw accurate inferences from it
face validity
when the measure appears to assess what it is meant to measure
content validity
when the measure assesses all of the parts of a defined construct
convergent validity
when the measure correlates (positively or negatively) with other constructs it should be associated with
discriminant validity
when the measure correlates weakly or not at all with constructs it is not associated with
generalizability
the process of deriving a concept, judgement, principle , or theory from a limited number of specific cases and applying it more widely, often to an entire class of objects, events, or people.
descriptive statistics
summarize and describe characteristics of a data set (distribution)
inferential statistics
tells us how confident we can be in drawing conclusions or inferences about a population based on findings obtained from a sample
measure of central tendency
measures that describe a distribution in terms of a single statistic that is in some way “typical” of the sample as a whole. (mode, median, Mean)
measure of variability
measures that provide info about the spread of scores in a deviation (range , standard deviation)
statistical significance
term that suggests that it is unlikely that a particular finding occurred by chance alone
p-value
the probability of finding the observed , or more extreme, results when there is no true effect. p> 0.5 is most commonly used
practical significance
statistical significance only tells us there is (likely) an effect (does not tell us how much of an effect or its practical value)
general ethical principles of the APA
Beneficence and nonmaleficence, fidelity and responsibility, integrity, justice, respect for peoples rights and dignity
the three Rs of animal research
replacement: try not to use animals
reduction: reduce amount of animals used
refinement: study should cause as little distress as possible
