Download Designing & Choosing Research Methods in Psychology: Observational vs. Experimental - Prof and more Study notes Psychology in PDF only on Docsity! PSY 138-Lecture#3 Designing Your Research -Generally the process involves a number of steps: – Identification of your research questions – identifying your variables – specify your hypotheses (how are the variables related to one another) – selecting a research design – collecting your data, analyzing your data – drawing conclusions from your data about your hypothesis Selecting Your Research Method -Observational: involves examine variables as they already are -Randomly select individuals -Watch their study habits -See how they do on a test -Experiential: involve manipulation of variables -Randomly select individuals -Randomly assign to groups -See how they do on a test -All experiments must make some sort of comparison -Why? The systematic reduction and control of variability of the IV(s) allows us to examine whether they are sources of variability in the DV -If only one group: -If two groups: -There is natural variability in your DV -Still some natural variability in your DV -No comparison group, so can’t see if -But have constrained one source of the change in the IV leads to change in the DV variability -Can’t make casual clams -Can see if there is an effect of the change -This is an observational design -Change in the IV leads to the change in the DV Called “one-shot case study design” -Change in the IV leads to the change in the DV Variables -Independent: these are variable that are manipulated by the experimenter -A number of ways to manipulate your IV – Event/Stimulus manipulations – manipulate characteristics of the stimuli, context, etc. – Instructional manipulations – different groups are given different instructions – Subject manipulations – there are (pre-existing mostly) differences between the subjects in the different conditions (typically results in quasi-experimental designs) -Dependent: these are the variable that are measured by the experiment, there are “dependent on the independent variables -Extraneous -Control: holding things constant; controls for excessive random variability -Random: may freely vary, to spread variability equally across all experimental conditions -Confound: other variables, that haven’t been accounted for (manipulated, measured,, randomized, controlled) that co-vary with the IV(s) and can impact changes in the dependent variable, sometimes called lurking variables Validity: are we testing what we want to test? -Internal: did the change result from the changes in the DV or does it come from something else -External: are experiments “real life” behavioral situations? “Does the process of control put too much limitation on the way things really work?”
