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