The formal, systematic application of the scientific method to the study of problems.
Major func: test hypotheses derived from an existing theory
- knowledge based on on observation
- (they can be misleading & are often misinterpreted).
Hypothesis (research hypothesis)
a statement indicating what results are expected
prediction of the outcome of a study
treatments are given for the research purpose: causes and effect, observe change in bx
observe participants in order to describe them as they naturally exist (survey, poll)
receives the treatment
not exposed to conditions
backgroud characteristics: socioeconomic status, age, race, etc.
Causal-comparative study (ex post facto study)
Researchers observe a current condition and look to the past to try to explain the cause.
Describe the attiudes, beliefs, and bx of a population.
a count (or study) of all members of a population
Usually involves only one participant.
Study over a long period of time
Research the degree of relationship among two or more quantitative variables.
Numbers. Data can be quantified, allowing for statistical analysis.
Deductive approach to planning - use literature as bases for planning research
Select random sample
Generalize the results to one or more populations
Formed judgment to identify major and minor themes expressed by participants. (Semi-structured interviews.)
Inductive approach to planning - deemphasize literature for planning research
Summarize result by citing individuals' response
Limit conclusions to only the indiv who were directly studied
a trait or characteristic with two or more categories
Mutually exclusive categories
Each respondent will belong to only one category.
A variable must have a category for each respondent opinion
stimulus or input / predictor
response or output / criterion
May be substituted for a nondirectional hypothesis.
Operationalizing a variable
Redefine a variable in terms of physical steps
(creates operatonal definition)
nonexperimental research to firgure out what are the practical needs of served by the program
provide a whole picture of what is and is not known, as well as atempt to show how diverse pieces of information fit together and make sense
group in which researchers are ultimately interested
Give every member of an population an equal chance to be part of the sample
may use simple random sample
may use sample of convenience/accidental
Volunteerism - call for, may not participate
Simple random sample
Every member of a population is given an equal chance of being included in a sample.
(drawing names from a hat)
Errors created by random sampling
(disporportionality of gender, etc.)
(very similar to simple random sampling)
Every nth individual is selected.
Technical term for discussing the magnitude of sampling errors.
Stratified random sampling
To use stratification in conjunction with random sampling.
Researchers draw random groups (clusters) of participants instead of drawing individuals.
Researchers puposively select individuals who they believe will be good sources of information.
Useful when attempting to locate participants who are hard to find.
participants drop out of experiements
special type of sampling bias results in experiments
Studies designed to obtain preliminary information on how new treatments and instruments work.
Any type of measurement device (e.g. test, questionnaire, interview schedule, or personality scale).
Validity of instruments
An instrument is valid when it measure what it is deigned to measure and accurately performs the function(s) it is purported to perform.