Internal Validity - Control influences btw variables w/in experiment

Question 1

Testing Effect

Answer 1

method repeated in a study where subject practice can improve performance

Question 2

Testing Effect Correction

Answer 2

Correct by having practice sessions, repeated measures

Question 3

History Effect

Answer 3

events occurring at the same time as the study, unpredictable and predicate

Question 4

History Effect Correction

Answer 4

correct through scheduling, control group

Question 5

Instrumentation Effect

Answer 5

any changes in the instrument of measuring device used for testing

Question 6

Instrumentation Effect Correction

Answer 6

correct by calibrating, investigator training, consistent operational definitions, select better tools

Question 7

Statistical Regression to Mean

Answer 7

pairing subjects that have opposite and extreme values for the measured variable will begin regressing toward the mean

Question 8

Statistical Regression to Mean Correction

Answer 8

correct – eliminate outliers, average repeated baseline measures

Question 9

Maturation Effect

Answer 9

changes in subjects performance because of the time that has elapsed

Question 10

Maturation Effect Correction

Answer 10

time control group, scheduling

Question 11

Experimental Mortality/Attrition

Answer 11

Loss of subjects during study, increase as the subject commitment level increase, investigator should assess if this affects a particular group over another

Question 12

Experimental Mortality/Attrition Correction

Answer 12

correct – replacement, alternate form of analysis

Question 13

Diffusion of Treatment

Answer 13

When subjects in the experimental group talk with subjects in the control group

Question 14

Diffusion of Treatment Correction

Answer 14

separation of subjects, instructions for adherence, masking

Question 15

Contamination

Answer 15

Bias occurs when the researcher has previous knowledge concerning the subjects in the experiment

Question 16

Contamination Correction

Answer 16

double blind studies

Question 17

Assignment of Groups

Answer 17

leads to unequal distribution of subject characteristics

Question 18

Assignment of Groups Correction

Answer 18

probabilistic assignment

Question 19

Selection Bias

Answer 19

leads to a sample that is not representative of the population from which it was drawn

Question 20

Selection Bias Correction

Answer 20

probabilistic selection, multiple sampling sites

Question 21

Interactions with Selection Bias

Answer 21

leads to changes in DV that may look like a treatment effect, Selection Maturation Effect (when groups experience maturation changes at different speeds) Selection History Effect (when groups come from different setting so that local history of each group influences responses) Selection Instrumentation Effect (avg. scores for various points are not accurately represented when the instrument does not register equal intervals across the full range of measurement

Question 22

Interactions with Selection Bias Correction

Answer 22

randomly assign subjects for all

Question 23

Compensatory Rivalry/Resentful Demoralization

Answer 23

subjects change behavior upon learning that they are in the control group

Question 24

Rivalry/Resentful Demoralization Correction

Answer 24

separation of subjects, adherence instructions, masking

Question 25

Compensatory Equalization

Answer 25

purposeful or inadvertent supplementation of the control group, therapist who works with control patient may work extra hard on exercises to compensate or missing the experimental treatment

Question 26

Compensatory Equalization Correction

Answer 26

correction – masking, standardization of protocol for intervention administration

Question 27

Ambiguity of Direction of Causal Influence

Answer 27

did X cause Y or did Y cause X

Question 28

Ambiguity of Direction of Causal Influence Correction

Answer 28

correction – manipulation of IVs to make temporal sequence more obvious