Study announcement if you are interested!

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Study announcement if you are interested!
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Questions

• Is there one type of mixed design that is more
  common than the other types?
• Even though there are a lot more participants in
  a between subjects factorial design than within
  subjects, does this complexity lead researchers
  to be more apt to using within subjects rather
  than between subjects?
• Is there a maximum number of factors or is it
  limitless if you can make a study around them?
• How would you draw 2x2x4 experiment?
• If a variable causes increased variance should
  you make that variable a factor?
• If you have a 3-factor study do all three lines
  have to cross to indicate an interaction between
  the factors?

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More Questions

• What is the significance of an interaction in a
  given study that uses a factorial design?
• Is it always necessary to use statistics in an
  experiment?
• On the upcoming exam, can you please provide a
  list of key terms for us to reference so that we
  can focus on understanding their meaning and
  application rather than vocabulary lists?
• Is there a way to know our grades before the
  final?
• For the extra credit paper can it be a critique
  about a topic we discussed in class?

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Descriptive and Correlational Research Strategies

• Chapters 12 and 13
• Dusana Rybarova
• Psyc 290B
• May 31 2006

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Outline

• Observational research design
• Survey research design
• Case study design
• Correlational research strategy

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Introduction

• both the descriptive and correlational strategies
  are nonexperimental approaches to research
• no attempt to manipulate or control or interfere
  with the variables
• descriptive strategy
• measures a variable(s) as they exist naturally
• the goal is to describe the variable(s)
• three descriptive research designs will be
  considered
• observational research, survey research, case
  study research
• correlational strategy
• measures two or more variables as they exist
  naturally
• the goal is to establish that a relationship
  exists between variables

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1. Observational research design

• in the observational research design the
  researcher observes and systematically records
  the behavior of individuals in a order to
  describe the behavior
• naturalistic observation
• a researcher observes behavior in a natural
  setting as unobtrusively as possible
• e.g. observing the behavior of children in a
  classroom
• () behavior is observed in the real world
• (-) time consuming, potential for observer
  influence

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1. Observational research design

• participant observation
• the researcher engages in the same activities as
  the people being observed, in order to observe
  and record their behavior
• e.g. gang meeting or treatment of mental patients
• () get info not accessible otherwise
• (-) time consuming, can be dangerous

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1. Observational research design

• contrived observation
• observation of behavior in settings arranged
  specifically for observing and recording of
  behavior
• e.g. parent-child interactions
• () dont have to wait for the behavior to occur
• (-) less natural

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2. Survey research designs

• a research study that uses a survey to obtain a
  description of a particular group of individuals
  is called a survey research design (only
  describing)
• e.g. customer surveys, eating behavior surveys
  etc.
• constructing a survey
• e.g. demographic questions at the end of survey,
  sensitive questions in the middle of the survey,
  appropriate vocabulary

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2. Survey research designs

• three types of questions
• open-ended questions
• e.g. What do you think about environmental
  pollution?
• advantages (flexibility)
• limits (different interpretations of questions,
  different format and length of answers, difficult
  to quantify)
• restricted questions
• you present the participant with a limited number
  of response alternatives (e.g. multiple choice
  questions)
• advantages (easy to quantify and analyze)
• limits (less flexible than open-ended questions)

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2. Survey research designs

• Self-report measures (cont.)
• types of questions (cont.)
• rating scale questions
• require a participant to respond by selecting a
  numerical value on a predetermined scale
• participants have the tendency to avoid the two
  extreme categories (actual scale is reduced by 2
  categories)
• participants tend to answer all of the questions
  in the same way (this is called response set)
• semantic differential (presents a list of
  adjectives, e.g. honest, and asks participants to
  use the scale to rate how well each adjective
  describes a particular individual (not
  descriptive ?describes perfectly))

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2. Survey research designs

• selecting relevant and representative
  participants
• e.g. specific groups
• administering a survey
• mail surveys
• convenient and nonthreatening but response rates
  are low
• phone surveys
• can be conducted from home but time consuming
• in-person surveys
• 100 response rate but time consuming with
  individual interviews

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3. Case study design

• involves the in-depth study and detailed
  description of a single individual
• may involve an intervention or treatment
  administered by the researcher
• when a study does not include any treatment or
  intervention, it is often called a case history
• e.g. Eve White (multiple personality disorder) or
  neuropsychological patients (H.M.)

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3. Case study design

• strengths
• not averaged over a diverse group
• detailed description
• vivid, convincing
• can study rare and unusual events
• can identify exceptions to the rule
• weaknesses
• limited generalizations
• potential for selective bias
• potential for subjective interpretations

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4. Correlational research strategy

• two variables are measured and recorded for each
  individual
• the measurements are then reviewed to identify
  any patterns of relationship that exist between
  the two variables and to measure the strength of
  the relationship
• can be used for making predictions
• first variable is called predictor variable (e.g.
  GRE score)
• second variable is called criterion variable
  (e.g. academic performance)

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4. Correlational research strategy

• Positive relationship
• There is a tendency for two variables to change
  in the same direction as one variable increases,
  the other also tends to increase.
• Negative relationship
• There is a tendency for two variables to change
  in opposite directions increases in one variable
  tend to be accompanied by decreases in the other.

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4. Correlational research strategy
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4. Correlational research strategy

• Applications of the correlational strategy
• Prediction
• Predictor variable (e.g. GPA)
• Criterion variable to be predicted (e.g. grad
  school success)
• Reliability and validity
• Calculating correlations in test-retest
  reliability and concurrent validity
• Evaluating theories
• E.g. Heredity and IQ correlations between twins

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4. Correlational research strategy

• strengths
• nonintrusive natural behaviors
• high external validity
• weaknesses
• cannot assess causality (e.g. TV and aggressive
  behavior)
• third-variable problem
• directionality problem
• low internal validity