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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 variabl9451
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1. Study announcement if you are interested!
2. 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?
3. 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?
4. Descriptive and Correlational Research Strategies Chapters 12 and 13
Dusana Rybarova
Psyc 290B
May 31 2006
5. Outline: Observational research design
Survey research design
Case study design
Correlational research strategy
6. 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
7. 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
8. 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
9. 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
10. 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
11. 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)
12. 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))
13. 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
14. 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.)
15. 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
16. 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)
17. 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.
18. 4. Correlational research strategy
19. 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
20. 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