9/24/2014 UNIT 2: RESEARCH METHODS AND STATISTICS RESEARCH METHODS RESEARCH METHODS RESEARCH METHODS

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1 RESEARCH METHODS UNIT 2: RESEARCH METHODS AND STATISTICS 8-10% of AP Exam Case Studies A case study is an in-depth study of one person. In a case study, nearly every aspect of the subject's life and history is analyzed to seek patterns and causes for behavior.. Advantages The hope is that learning gained from studying one case can be generalized to many others Allows us to get information about situations that we can t or won t recreate ex: Genie Disadvantages Tend to be highly subjective Difficult to generalize results to a larger population. Can be costly RESEARCH METHODS RESEARCH METHODS Surveys Questionnaires or interviews are given to a select group Advantages Cost-effective Lots of data Can measure attitudes Disadvantages Wording effect Wording may influence answers Dishonesty Small rate of return not likely to be representative Naturalistic Observation Study behavior in its natural context Advantages Observed behavior will be more natural, spontaneous and varied Disadvantages No control over behavior/situation Observer Bias Expectations influence what was seen Ignore seemingly nonrelevant behavior 1

2 RESEARCH METHODS RESEARCH METHODS Correlational Research Based on the naturally occurring relationship between 2 or more variables Advantages Make Predictions Suggests connections/strength of relationships Disadvantages Does NOT explain CAUSE and EFFECT Experimental Research Manipulates variables and measures their effects on subsequent behavior. Advantages Describes CAUSE and EFFECT Control of variables Disadvantages Hard to measure some things (love, hatred, grief) Ethical issues Artificial setting-behavior may change NOW. With a partner, find an example of each type of research as it applies to psychology Discuss why this is/isn t the best way to study this particular information Submit answers via or on notebook paper 2

3 OPERATIONAL DEFINITIONS OPERATIONAL DEFINITIONS Identifies one or more specific, observable events or conditions such that any other researcher can independently measure and/or test for them. Example: A researcher is measuring happiness and depression in college students. Ten question happiness scale to measure positive outlook Operational definition of happiness in this case is the subject s score on the test. So basically.. Precise description of WHAT we are measuring Let s practice! OPERATIONAL DEFINITIONS OPERATIONAL DEFINITIONS Correlational Study Relationship between hair length shoe size height What would be our operational definition for each? Ready for more?! With your table partner, create an operational definition for your given study! 3

4 CORRELATIONAL STUDY CORRELATIONAL RESEARCH How can we explain relationships? Correlation CANNOT prove causation Do democratic parents produce better behaved children? Do better behaved children encourage parents to be democratic? May be an unmeasured common factor e.g., good neighborhoods produce democratic adults and well-behaved children Doesn't t mean they are not useful 4

5 CORRELATION & CAUSATION There is a strong +.90 correlation in shoe size and IQ. Does this mean that a large shoe size is the cause for higher intelligence? What else could explain this? YOUR FEET GROW AS YOU GET OLDER & WISER COEFFICIENT OF CORRELATION HOW TO READ A CORRELATION Numerical indication of magnitude and direction of the relationship between two variables Positive correlation two variables vary systematically in the SAME direction Negative correlation two variables vary systematically in OPPOSITE directions 5

6 POSITIVE CORRELATION As the value of one variable increases (or decreases) so does the value of the other variable. A perfect positive correlation is The closer the correlation is to +1.0, the stronger the relationship. NEGATIVE CORRELATION As the value of one variable increases, the value of the other variable decreases. A perfect negative correlation is The closer the correlation is to -1.0, the stronger the relationship. 6

7 ZERO CORRELATION Let s Review There is no relationship whatsoever between the two variables. 7

8 EXPERIMENTAL RESEARCH How can we determine Cause/Eff ect? THE SCIENTIFIC METHOD How psychologists begin any study FORMING THE HYPOTHESIS THE EXPERIMENTAL METHOD Keep the following points in mind when formulating a hypothesis: Use information you have gathered from various sources to help you formulate the hypothesis. Be sure the hypothesis is brief, preferably no more than one sentence. State in the hypothesis the results that you expect from the study. Typically in the If, then format Ensure that the hypothesis can be tested. The prime method of enquiry in science is the experiment. The key features are: control over variables careful measurement establishing cause and effect relationships. 8

9 EXPERIMENTAL RESEARCH IV VS. DV: KNOWING THE DIFFERENCE Independent Variable Variable manipulated by researcher Dependent Variable Variable measured by researcher Experimental Group Experiences the manipulated variable Control Group Receives no treatment, serves as the baseline for comparison Use an If/Then Statement If this (independent variable) THEN this happens (dependent variable). If my subject drinks an energy drink (Ind. Variable) THEN they should get a surge in energy (Dep. Variable) OR They are testing the effect of (IV) on (DV). Good Way to Remember: An IV in your arm causes something to happen (DV) FLAWS IN EXPERIMENTAL RESEARCH CONFOUNDING VARIABLES Confounding Variables=Uncontrolled Factors Could affect dv Could confuse interpretation of data Uncontrolled Variables Uncontrolled factors that could have an impact on the results Ex: differences in subjects backgrounds, personalities, health, etc 9

10 CONFOUNDING VARIABLES HOW CAN WE CONTROL FOR BIAS? Participants Expectations If they KNOW they are in the experimental group, they may react differently Same goes for if they KNOW they are being observed Experimenter Bias Exp. Unintentionally affect the DV based on their expectations of results Use random assignment All participants have an equal chance of being assigned to the experimental group Placebo control group exposed to a fake IV (placebo) Effects are compared to group receiving the actual IV. Double Blind Study Neither the experimenter nor the participants know which group received the IV EXPERIMENTAL DESIGN Experimental design refers to how participants are allocated to the different conditions (or IV groups) in an experiment. There are three types: 10

11 SELECTING PARTICIPANTS EXPERIMENTAL DESIGN Sampling selecting a group of participants out of a target population Random Sample: Every member of the population has an equal chance of being chosen Ex: Shopping Survey Representative Sample (a.k.a. Stratified Sample) Used when random samples are not possible Participants selected to represent the characteristics of the population Independent measures / groups: Different participants are used in each condition of the independent variable. Ex: if 38% of population-male, then 38% of sample=male EXPERIMENTAL DESIGN Repeated measures: The same participants take part in each condition of the independent variable. EXPERIMENTAL DESIGN Matched pairs/between Groups: Each condition uses different participants, but they are matched in terms of certain characteristics, e.g. sex, age, intelligence etc. 11

12 THE IMPORTANCE OF REPLICATION Repeating the experiment to determine if similar results are found If so, the research is considered reliable. 12