Methods of Research • Rules for conducting research • two main methods: • correlational • experimental method • sub-areas of these, as well
Populations and samples • Population: • total number of all possible cases • those who have been, are now, and will be • Sample: • small portion of possible cases • usually representative • must reflect characteristics of a population
Non-experimental methods • Naturalistic observation • observe in “nature” • non-intrusive • case study • one or a few special cases • can be intrusive or non-intrusive
Non-experimental Method: Surveys or Questionnaires • Questions answered by a sample • intrusive (or at least somewhat) • must be sure get a representative sample • look for answering/questioning biases • people lie!
Correlational method • NON experimental • looking at relation between two variables • effect of X on Y • Correlation DOES NOT IMPLY CAUSATION • values of -1.0 to 0 to +1.0 • closer to 1.0 is stronger relationship • if value is close to 0, little relationship
Two types of correlations • Positive correlation: 0 to 1.0 • as X goes up so does Y • rate of waterskiing and outside temperature • Negative correlation: 0 to -1.0 • as X goes up, Y goes down • rate of hot chocolate intake and outside temperature
Experimental Method • Allows us to conclude causation • Uses general experimental method • hypothesis to test • uses INDEPENDENT and DEPENDENT variables
I.V. and D.V. • Variable = any characteristic or condition which is subject to change • Independent variable: what the experimenter manipulates or changes • Dependent variable: what the experimenter measures, what was changed by the I.V.
Several Important Steps: • Experimenter manipulates IV, measures DV • WAY that the IV is manipulated is important: • assumes using a random sample • control for extraneous (extra or outside) variables • use systematic observations
Types of Groups of IV • Experimental group: gets the treatment • Control group: • does not get the “treatment”, but otherwise equal to the experimental group • Placebo Group: • a control group • “thinks” they got the treatment
Examples: • Alcohol effects on test scores: • IV = level of alcohol intake • DV = test score • What types of groups might have? • Several levels of alcohol intake (1, 5, 20 beers) • control groups: no alcohol; placebo group
Possible Results: Examined effects of Training on come And stay in goats
Problems in Research: • Experimenter bias • way around: double blind procedure • Demand characteristics • Hawthorne Effect • Pygmalion Effect • Measurement problems (did you measure what you thought you measured?)
Ethics in Research • Humans: • right to privacy • voluntary participation • informed consent • no unjustifiable deceit • no lasting harm
Use of Animals • Animal rights regulations: • IACUC • USDA • NIH/NSF • Controls acquisition, care, use and disposal of animals • Scientists must be properly trained, mimimize discomfort and pain, and meet all requirements of IACUC