chapter 1 (intro) Flashcards
research
process of gathering info systematically to answer questions and test theories. uses statistics.
data
information collected as part of a research project and expressed as numbers.
statistics
set of mathematical techniques for organizing and analyzing data. sometimes also refers to numbers obtained from statistical techniques.
theory
generalized explanation of the relationship between 2+ variables.
variable
any trait that can change values from case to case.
independent variable
variable that is identified as a causal variable. causes dependent.
dependent variable
variable identified as an effect, result, or outcome. thought to be caused by independent variable.
hypothesis
statement about relationship between variables derived from a theory. more specific than theory. terms and concepts are fully defined.
descriptive statistics
branch of stats concerned with:
1. summarizing distribution of single variable.
2. measuring relationship between two or more variables.
describing raw study data. goal is data reduction.
data reduction
summarizing many scores with a few statistics. major goal of descriptive stats.
measures of association
stats that summarize the strength and direction of relationship between variables. provide clues about causation.
sample
carefully chosen subset of population.
population
total collection of cases in which researcher is interested.
inferential statistics
branch of stats concerned with generalizing from samples to populations. two general uses: estimation and hypothesis testing.
discrete variable
variable with basic unit of measurement that cannot be subdivided. (ex: number of siblings, people per household.)
continuous
variable with a unit of measurement that can be subdivided indefinitely. (ex: time.)
level of measurement
mathematical characteristic of variable and major criterion for selecting statistical techniques. determined from examination of response categories.
the three levels are:
1. nominal.
2. ordinal.
3. interval-ratio.
response categories
variable’s possible attributes, qualities, characteristics.
nominal variable
variable whose response categories can be classified but not ordered. category criteria:
1. mutually exclusive.
2. exhaustive.
3. relatively homogeneous.
ordinal variable
variable whose response categories can be classified and ordered. (ex: options from lower to upper class, likert scale.)
interval-ratio variable
variable whose response categories can be classified and ordered and have equal distance between them.
