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Theories Hypotheses

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					Psychology as a science


Psych 231: Research Methods in
Psychology
Announcements

   For this week’s lab you need to
    download, print out, read, and bring to
    lab an article.
    – The article is: Strayer & Johnston (2001)
    – It can be downloaded from the Milner
      library page:http://www.mlb.ilstu.edu/
The anatomy of a research article
   Method - tells the reader exactly what was done
      Enough detail that the reader could actually replicate
       the study.
      Subsections:
          Participants - who were the data collected from
          Apparatus/ Materials - what was used to conduct the
           study
          Procedure - how the study was conducted, what the
           participants did
The anatomy of a research article

       Reading checklist for Methods
         1 a) Is your method better than theirs?
           b) Does the authors method actually test the hypotheses?
           c) What are the independent, dependent, and control variables?
         2) Based on what the authors did, what results do YOU expect?
The anatomy of a research article
   Results - gives a summary of the results and the
    statistical tests
      Reading checklist
        1) Did the author get unexpected results?
        2 a) How does the author interpret the results?
          b) How would YOU interpret the results?
          c) What implications would YOU draw from these results?
The anatomy of a research article
   Discussion - the interpretation and implications of
    the results
      Reading checklist
         1 a) Does YOUR interpretation or the authors' interpretation
           best represent the data?
           b) Do you or the author draw the most sensible implications
           and conclusions?
   References - full citations of all work cited
   Appendices - additional supplementary
    supporting material
Psychology as a science
 Psychology’s goals are similar to the goals of
  the physical sciences (e.g., physics and
  chemistry)
 Psychologists are concerned with the
  behavior of people (and animals) rather than
  the physical world.
Psychology as a science

   How is psychology different from the physical
    sciences?
    – One big difference is that human behavior (and
      animals) is typically much more variable than most
      physical systems.
       • To address this in part, we use a lot of statistical
         procedures.
       • We also do as much as we can to reduce variability by
         using various methods of control.
Goals of psychology
   Description of behavior
    – describe events, what changes what might affect
      change, what might be related to what, etc.
   Prediction of behavior
    – given X what will likely happen
   Control of behavior
    – for the purpose of interventions (e.g., how do we
      prevent violence in schools)
Goals of psychology
   Causes of behavior
    – sometimes predictions aren’t enough, want to
      know how the X and the outcome are related
   Explanation of behavior
    – a complete theory of the how’s and why’s
Properties of a good theory

   Organizes, Explains, & Accounts for the data
    – If there are data relevant to your theory, that your
      theory can’t account for, then your theory is wrong
       • either adapt the theory to account for the new data
       • develop a new theory that incorporates the new data
Properties of a good theory

 Organizes, Explains, & Accounts for the data
 Testable/Falsifiable – can’t prove a theory,
  can only reject it
    –our research goal is not to prove theories, but rather to
     disconfirm them. Results may “support” theories,
     but not “prove” them.
Support, not proof
 Einstein: “No amount of experimentation can
  ever prove me right; a single experiment can
  prove me wrong.”
 “All dogs have four legs”
    – hard to prove, need to examine all the dogs that
      exist (and have existed).
    – To disconfirm all we need to do is find one dog
      which doesn’t have four legs
Omnipotent Theory

   Beware theories that are so powerful/
    general/ flexible that they can account for
    everything. These are not testable
    – Karl Popper claimed that Freudian theory isn’t falsifiable
        • If display behavior that clearly has sexual or aggressive
          motivation, then it is taken as proof of the presence of the Id
        • If such behavior isn’t displayed, then you have a “reaction
          formation” against it. So the Id is there, you just can’t see
          evidence of it.
    – So, as stated, the theory is too powerful and can’t be tested
      and so it isn’t useful
Properties of a good theory
 Organizes, Explains, & Accounts for the data
 Testable/Falsifiable
 Generalizable – not too restrictive
    – the theory should be broad enough to be of use,
      the more data that it can account for the better
    – the line between generalizability and falsifiability is
      a fuzzy one.
Properties of a good theory
 Organizes, Explains, & Accounts for the data
 Testable/Falsifiable
 Generalizable
 Parsimony (Occam’s razor)
    – for two or more theories that can account for the
      same data, the simplest theory is the favored one
Properties of a good theory
   Organizes, Explains, & Accounts for the data
   Testable/Falsifiable
   Generalizable
   Parsimony
   Makes predictions, generates new knowledge
    – a good theory will account for the data, but also
      make predictions about things that the theory
      wasn’t explicitly designed to account for
Properties of a good theory
   Organizes, Explains, & Accounts for the data
   Testable/Falsifiable
   Generalizable
   Parsimony
   Makes predictions, generates new knowledge
   Precision
    – makes quantifiable predictions
Using theories in research
   Induction – reasoning from the data to the general
    theory
    – So in complete practice this approach probably needs a new
      theory (or an adapted one) for every new data set
   Deduction – reasoning from a general theory to the
    data
    – Here the theory (if it is a “good” one) is sometimes viewed as
      more critical than the data. It also will guide the choice of
      what experiments get done
The chicken or the egg?
                   Theory

    induction                      deduction


                    Data

   Typically good research programs use both
Research Approaches
   Basic (pure) research - tries to answer fundamental
    questions about the nature of behavior
    – e.g., McBride & Dosher (1999). Forgetting rates are
      comparable in conscious and automatic memory: A
      process-dissociation study.


   Applied research – Theory sometimes takes a
    backseat. This is research designed to solve a
    particular problem
    – e.g., Jin (2001). Advertising and the news: Does advertising
      campaign information in news stories improve the memory of
      subsequent advertisements?
Research Approaches
   Probably the best way to think of this is as a
    continuum rather as two separate categories.



Basic research                             Applied research

     • Often applied work may bring up some interesting
     basic theoretical questions, and basic theory often
     informs applied work.
Next time

 Basic Methodologies
 Read Chapters 6 and 7

				
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