Chapter 7 Flashcards
Non-experimental research
describes participants, traits, scores, and other characteristics without direct or active intervention.
Does not assess causal relationships, though it may suggest them in some designs (e.g., causal-comparative)
Characteristics of Descriptive Studies
Describes a phenomenon
Useful when an area is first being investigated
Many studies, descriptive included, have more than one design type incorporated (so only parts of the study may be truly descriptive)
Criteria for Evaluating Descriptive Studies
Conclusions about relationships should be made with caution
Subjects and instrumentation should be well described
Relationship (Association)
The finding that one variable varies systematically with another variable
Relationship are important because:
They identify potential causes of relationships
They identify variables that can be investigated in true experiments
They allow the prediction of one variable from another
Characteristics of Comparative Studies
Investigates the relationship of one variable to another by comparing values of the DV among differing groups (which serve as the IV)
Does not assess causation, because individuals have not been randomly assigned to an intervention
Does allow prediction of the DV as a function of group membership
Criteria for Evaluating Comparative Studies
Subjects, instrumentation, and procedures should be well defined
Identify the criteria for establishing different groups
Do not infer causation from comparative research designs
Graphic presentations should not distort the results
Characteristics of Correlational Studies
Involves two (or more) variables
A scatterplot is constructed for each set of two variables
Pairs of variables are related using correlation coefficients
The size of correlations is limited by the reliability of the variables
Both the x and y variables need to be sampled over a wide range
If large numbers of variables are correlated, some correlations will show up as significant due to chance alone
Large samples may yield significant correlations that have very small effect sizes
Prediction Studies
A correlation between two variables means that one variable can predict the other variable through a procedure known as regression
Prediction in a new sample of subjects is always ________________ than in the sample that was used to derive the original prediction equation
smaller
Factors That Can Limit Prediction
Reliability of the scores
Length of time between criterion and predictor
Complexity of the criterion variable
Multiple Regression Analysis
Uses multiple predictors to predict a single criterion
Yields a multiple correlation coefficient, R
Best when the multiple IVs have only low to moderate correlations with each other
Logistic Regression
Used when the criterion variable (DV) is dichotomous
Criteria for Evaluating Correlational Studies
Causation should rarely be inferred from correlation
The reported correlation should not be higher or lower than the actual relationship
Practical significance should not be confused with statistical significance
The size of the correlation should be sufficient for the use of the results
Prediction studies should report accuracy of prediction for new subjects
Procedures for collecting data should be indicated clearly
Correlational studies that claim explanations should be examined for other influential factors
Causal-Comparative Designs
These designs compare groups of pre-existing groups
The experimenter cannot assign participants to conditions in these studies
Because random assignment is not possible, these designs are essentially correlational, and not experimental
