Chapter 2 Lecture Science How Scientific Psychologists Do Research Bad Psychology Has Ruined Lives o People have gone to prison because of facilitated communication o Untested treatments for mental illness can be expensive yet ineffective o Poor educational practices can make it hard for children to get adequately prepared for college and the workforce o Bade relationship advice on T V radio and even among licensed counselors routinely ruins marriages Science Can Be Wrong But o Science can be corrected when new research comes out o You can t correct pseudoscience o Bad practices and theories survive because you can t prove they re bad Falsifiability if a hypothesis is wrong then it is possible to prove that it is wrong Types of Scientific Research 1 Naturalistic Observation 2 Case Studies 3 Correlation Designs 4 Experimental Designs Naturalistic Observation o You go out among people or animals and record and describe behaviors you o You observe your subjects in their natural habitat and try to interfere as little are interested in as possible o It is usually an earl step in the research process because you can only describe record behaviors but it is impossible to be sure what is causing a behavior o If people or animals notice they re being watched they will often change their behaviors in response o Often used to generate hypotheses you will test more rigorously later o Used in psychiatry and clinical psychology o Some disorders and brain injuries are rare In order to understand them you have to study patients when you get them o Usually case studies can involve at least on of the components below Case Studies 1 The patient performs a battery of cognitive tests 2 The patient s symptoms are described in detail 3 The patient s treatment is described in detail 4 The patients progress is tracked over time o Since case studies only involve on person you have to be careful not to overgeneralize findings Correlation Designs o A correlation is a relationship between two variables o A variable is something that can be measured o Essentially you can find out if any two things that are measurable or categorized are related Correlational Studies o A correlation coefficient is a numerical representation of a correlation it can have a value between 1 and 1 o Two variables can be correlated without one causing the other o Correlation is a necessary to determine if two variables have a causal relationship But it s not sufficient Experimental Design To see if there is a correlation between how many pushups a person can do can make a person bench press more weight o Experiment Terms Independent Variable Number of pushups Dependent Variable Number of pounds you can bench press Experimental groups The 25 pushup a day group the 50 pushup a day group and the 100 pushup a day group Control ground the group that does not pushups Baseline The amount of weight people can press before the experiment begins o Experiment Procedure 400 college students Randomly assigned to groups 100 people per group If it was truly random then the average should be the same on the first day On first day people bench press their max The participants do their assigned number of pushups everyday At end everyone benches their max again Scientists then do statistics of the groups to figure out if it worked o Experiment Confounds There can be some people like athletes in the group that mess up the data o Experiment Double Blind Experiments Sometimes when you test new medicines and treatments you have to be worried about the placebo effect The placebo effect is when someone s health improves because they believe it will improve Very real and surprisingly powerful Still a good medicine will help people improve more than the placebo effect does In order to be sure a medicine is causing improvement beyond just the placebo effect scientists must employ the double blind procedure Half get the real meds and the other half gets a placebo o Correlational studies and Experiments usually involve a lot of participants The best studies have hundred or even thousands of respondents o This raises three questions When 2 variable correlate how strong does the correlation have to be to conclude that it is reliable and not just chance Statistics and Sampling Sampling Average scores at the end of the exp How big does the difference have to be in order to conclude that it is reliable and not just chance How do we know if it is representative of the whole o Random Sampling If you select people from the sample the demographic breakdown of the sample will approach the demographic breakdown of the population as the sample gets bigger o Stratified Sampling Make sure that you slots are reserved for the specific category and then randomly select from the category to fill those slots
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