Presentation on theme: "Study announcement if you are interested!. Questions Is there one type of mixed design that is more common than the other types? Even though there."— Presentation transcript:
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?
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?
Descriptive and Correlational Research Strategies Chapters 12 and 13 Dusana Rybarova Psyc 290B May 31 2006
Outline: 1.Observational research design 2.Survey research design 3.Case study design 4.Correlational research strategy
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
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
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
1. Observational research design contrived observation –observation of behavior in settings arranged specifically for observing and recording of behavior –e.g. parent-child interactions –(+) don’t have to wait for the behavior to occur –(-) less natural
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
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)
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))
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
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.)
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
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)
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.
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
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