PSY 0010 notes Research Methods in Psychology page 1 Theory explains set of facts observations Describes causal connections Is falsifiable Possible that evidence against can be found Anything that cannot be falsified is not a theory Contrast with faith cannot be falsified so not a theory Allows prediction of new observations If x causes y in z situation x in z y Research tests a theory by testing its predictions Systematic and objective observation EX what is the relationship between violence on TV and aggression in children Scientific method 1 observe 2 generalize from observations Will observation repeat in multiple situations Hypothesis testable proposition describing the relationship that may exist Cannot study entire population need a sample to study and draw 3 develop a theory 4 test the theory 5 revise theory Testing a theory between events If then Testing hypothesis who will be observed conclusions about population What method of observation will be used Descriptive Methods Naturalistic observation Real world settings Advantages Discovery of initial connection Real world applicability Disadvantages Uncontrolled Might be other influences Observer bias may influence observations Other approach case study Observe and describe a single individual PSY 0010 notes Research Methods in Psychology page 2 EX memory research HM brain surgery changed memory Most of our current knowledge on memory comes from his case study Advantages to case studies Rich detail Access to rare phenomena Proof of existence proves some things are possible Disadvantages Uncontrolled Problem of generalizability 3rd approach surveys interviews Obtain a representative sample that mirrors the population of interest Randomly select participants in theory gives each part of population an equal chance to be in the study Administer self report measures i e interview questionnaires Advantages Generalizable Efficient cost effective Disadvantages Sample vs population how representative is the sample Logistically challenging Response biases Social desirability they might look bad if answering truthfully so answers not always truthful Experimental Methods Systematically vary an aspect of situation control all others observe measure effects to establish a cause effect relationship Aspect of situation variable must have at least 2 values Elements of experiment Independent variable manipulated by researcher cause Dependent variable measured byr esearcher effect EX hypothesis if kids exposed to violent TV then aggression will increase Independent variable violent TV Dependent variable aggressive behavior Operational definition specify and define phenomena of interest so they can Other elements be experimentally studied PSY 0010 notes Research Methods in Psychology page 3 Define IV so manipulation possible exposure to X hours violent TV Define DV so measurement possible number of aggressive behaviors Controlling uncontrolled variables Assignment of participants to groups experimental control groups Control group exposed to experimental environment but not IV Randomization ensures equivalent groups before the IV is manipulated Conducting a Study Collecting data Analyzing results info gathered by researcher used to test hypothesis statistical analyses determine acceptance or rejection of hypothesis Publishing and replicating study peer review critique by other researchers before publication anonymous publication hypothesis methods participants results discussion discussion important to the continuation of science republication repetition of study by other researchers to see if same results NEVER treat findings of any study as definitive implications limitations future research needed are found Analyzing Data with Statistics Stats 2 types of stats in psych methods for analysis interpretation presentation of numerical data 1 descriptive stats 2 inferential stats are these numbers values meaningful used to test hypothesis Descriptive Stats measures of central tendency the average person single score representative of entire set of data mean arithmetic average median less affected by outliers in the set than the mean mode most frequently occurring value measures of variability how similar diverse scores are frequency number of times a number appears in data set frequency distribution chart normal distribution bell curve scores cluster around the middle can calculate standard deviation SD measure of how much scores will vary around the mean larger SD more variability in the data if a 5 68 of scores fall between 95 and 105 if mean is 100 smaller SD more the mean mean represents the average score PSY 0010 notes Research Methods in Psychology page 4 basically SD give or take a amount Measures of effect size how large is the effect of the IV size of difference between distribution of scores in the experimental group vs the control group difference between 1 control and 10 experimental as mean in kids aggression study and 2 control and 4 experimental significant Cohen s d represents difference between means of two distributions smaller d lesser difference between means in psych d of 5 can be significant enough to use intervention treatment Inferential Stats significance testing how likely that difference in DV due to chance error luck rather than caused by IV calculated with probability level p t test used to calculate compute two means to see how probable it is they come from the same population ask what is probability of findings being luck not probability of them being true in psych if chances 5 that finding was luck and 95 correct hypothesis the finding is valid if much higher than 5 redo or confirm no hypothesis normally written p 05 etc etc today more within p 01 than p 05 do not confuse effect size and significance can have huge effect size but no significance because of bias etc or huge significance but barely any effect increased IQ by 1 point etc 2 Traditions in Psych 1 applying psych knowledge to real world problems practical applied psych development of therapies psychotherapy counseling education 2 developing psych knowledge via scientific research academic tradition empiricism gain knowledge through direct observation of subject matter