Term
| External Design or Experimental Validity |
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Definition
is concerned with factors that may affect how the study findings/conclusions can be generalized to a larger population.
They are known as threats to external validity. |
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Term
| What three items are needed for a "true" (classical) experiment design? |
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Definition
Random assignment
Control
Manipulation |
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Term
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Definition
| In research means the researcher/investigator/ experimenter is doing or has done something to the subjects in the study (the experiment). |
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Term
| What is another name for independent variable? |
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Definition
experimental variable
treatment variabele |
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Term
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Definition
| Refers to the experimenter’s ability to control or eliminate interfering and irrelevant influences from the study. |
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Term
| In some studies, frequently seen in medical studies, the control group may be manipulated, e.g. receiving a _______ therapy, while the experimental group receives a new, ___________ therapy. |
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Definition
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Term
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Definition
Concealment of facts from anyone who may influence the results of a study.
Not revealing which subjects are in the experimental group and which are in the control group. |
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Definition
| Either the experimenter OR the subjects do not know who is in which group. |
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Definition
| Both the experimenter AND the subjects do not know who is in which group. |
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Definition
| The experimenter, the subjects, AND the person analyzing the data (results) do not know who is in which group |
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Term
| T/F Blinding is always possible. |
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Definition
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Definition
| Changes to the research subjects due to the passage of time – especially in long-term experiments. Could change physically, mentally. Threat to internal validity. |
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Term
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Definition
| Changes brought about by the measuring procedure, threat to internal validity |
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Term
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Definition
| Note that here “mortality” does not mean “death” Withdrawal of subjects from the study, especially in experiments when there is differential attrition between the experimental and the control groups. |
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Term
| REGRESSION TOWARDS THE MEAN |
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Definition
Tendency for extreme subjects (outliers) to move toward the mean (average) (“normal”) of the experimental or control group with time.
This is important if the extreme . THREATS TO VALIDITY - INTERNAL |
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Term
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Definition
Event(s) that intervene during the study and affect the dependent variable, but are not part of the independent variable being studied.
THREATS TO VALIDITY - INTERNAL |
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Term
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Definition
| Errors in the initial process assigning subjects into groups. |
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Term
| CONTAMINATION or DIFFUSION or IMITATION OF TREATMENTS |
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Definition
| Subjects in the experimental manipulated group pass on some elements of the manipulation/treatment to some members of the control group. THREATS TO VALIDITY - INTERNAL |
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Term
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Definition
Subjects in the control group feel deprived of the manipulation and compensate by working harder.
THREATS TO VALIDITY - INTERNAL |
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Term
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Definition
| Instead of having compensatory rivalry, the control group feel deprived, and stop studying or study less than usual. |
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Term
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Definition
Subjects in the control group are usually deprived of something that might be of value (the experimental treatment or manipulation).
Someone, internal or external to the study, may feel sympathy for the control subjects and give them extra attention.
THREATS TO VALIDITY - INTERNAL |
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Term
| POPULATION-RELATED THREATS (external) |
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Definition
The subjects’ accessibility to the study
INITIAL SAMPLING
Subject-treatment interaction: |
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Term
| Subject-treatment interaction |
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Definition
| Basically this is the confounding effects of attributes or features of the subjects on the dependent variable. |
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Term
| Description of the variables |
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Definition
| must be described precisely and in sufficient detail for others to repeat the study. |
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Term
| Sequence of multiple treatments |
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Definition
| if two or more drugs or therapies are involved, possible interaction of these, or any effects of order given or timing, may affect the results. |
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Term
| Are Hawthorne effect, Rosenthal effect and Pygmalion effect external or internal threats? |
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Definition
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