Eppp- Statistics Questions And Answers
Quasi-experimental Design Cannot randomly assign participant to conditions. Has
preexisting groups or single group without control comparison.
Probability Sampling Each element in the target population has a known chance being
selected for inclusion in the sample. Is used to ensure sample is representative of sample
population.
Extraneous (Confound) Variable A source of systematic error that affects the relationship
between IV and DV.
Systematic Error Predictable error.
Random Error Error that is unpredictable (random). Sampling error and measurement
error are types.
Internal Validity How sure the experimenter can be that the IV caused change in the DV.
Maturation Threat to validity; physical change, event, or psychological process occurs as
the result of the passage of time; ex) fatigue, decreasing motivation). To control: more than one
group and randomly assign to groups.
, History Threat to validity; an event that is external to the research study affects subject's
performance on the DV in a systematic way. Control by: having more than one study group and
randomly assign participants
Statistical Regression Threat to validity; Extreme scores regress towards the mean.
Control by: Don't include only extreme scores in the study or use more than one group and all
groups have similarly extreme scores.
Selection Threatens internal validity when groups differ at the beginning of the study
because of the way subject were assigned to groups and is a potential threat whenever subjects
are not randomly assigned to groups.
External Validity Degree to which a study's results can be generalized to other people,
settings, and conditions. *Internal validity is required to achieve ____.
Pretest Sensitization Threat to External validity; Occurs when pretesting affects how
subjects react to the treatment. Control by: not administering a pretest or use solomon 4-group
design.
Reactivity Threat to external validity; Occurs when subjects respond differently to a
treatment because they know they are participating in a research study. 2 types: 1) Evaluation
Apprehension: avoid negative evaluation. 2) Demand Characteristics: cues in a study that inform
subjects of purpose of study or expected behavior.
Quasi-experimental Design Cannot randomly assign participant to conditions. Has
preexisting groups or single group without control comparison.
Probability Sampling Each element in the target population has a known chance being
selected for inclusion in the sample. Is used to ensure sample is representative of sample
population.
Extraneous (Confound) Variable A source of systematic error that affects the relationship
between IV and DV.
Systematic Error Predictable error.
Random Error Error that is unpredictable (random). Sampling error and measurement
error are types.
Internal Validity How sure the experimenter can be that the IV caused change in the DV.
Maturation Threat to validity; physical change, event, or psychological process occurs as
the result of the passage of time; ex) fatigue, decreasing motivation). To control: more than one
group and randomly assign to groups.
, History Threat to validity; an event that is external to the research study affects subject's
performance on the DV in a systematic way. Control by: having more than one study group and
randomly assign participants
Statistical Regression Threat to validity; Extreme scores regress towards the mean.
Control by: Don't include only extreme scores in the study or use more than one group and all
groups have similarly extreme scores.
Selection Threatens internal validity when groups differ at the beginning of the study
because of the way subject were assigned to groups and is a potential threat whenever subjects
are not randomly assigned to groups.
External Validity Degree to which a study's results can be generalized to other people,
settings, and conditions. *Internal validity is required to achieve ____.
Pretest Sensitization Threat to External validity; Occurs when pretesting affects how
subjects react to the treatment. Control by: not administering a pretest or use solomon 4-group
design.
Reactivity Threat to external validity; Occurs when subjects respond differently to a
treatment because they know they are participating in a research study. 2 types: 1) Evaluation
Apprehension: avoid negative evaluation. 2) Demand Characteristics: cues in a study that inform
subjects of purpose of study or expected behavior.
