Chapter 5

Question 1

experiment

Answer 1

systematic research study in which the investigator directly varies some factor(s), holds all others constant, and observes the results

Question 2

Independent variable

Answer 2

factor of interest to investigator, manipulated factor; situational, task, instructional

Question 3

situational variable

Answer 3

Type of IV, features of the environment that the observer might encounter

Question 4

task variable

Answer 4

Type of IV, groups get different types of problems to solve

Question 5

instructional variables

Answer 5

Type of IV, groups get different instructions for same task

Question 6

extraneous variables

Answer 6

not of interest to the investigator but may influence the behaviour being studied if not controlled

Question 7

confound

Answer 7

any uncontrolled extraneous variable that covaries WITH the independent variable and could provide an alternate explanation of the results

Question 8

ceiling effect

Answer 8

Dependent variable effect where avg scores for the group are so high that no difference can be determined between conditions

Question 9

floor effect

Answer 9

dependent variable effect where avg scores for the group are extremely low, usually because the task is too difficult for everyone and again producing a failure to find any differences between conditions

Question 10

subject variables

Answer 10

may be considered IV, subjects are chosen based on a particular similarity by the experimenter (less control than other IVs and can not make causal claims, only document different measures of DV)

Question 11

Statistical conclusion validity

Answer 11

concerns the extent to which the researcher uses statistics properly and draws the appropriate conclusions from statistical analysis

Question 12

ecological validity

Answer 12

Neisser - research with relevance for the veryday cognitive activities of people trying to adapt to their environment (opposite of experimental realism)

Question 13

Internal validity

Answer 13

Cook and Campbell - the degree to which an experiment is methodologically sound and confound free (researcher feels confident that results as mesured with DV are directly related to IV and not something else); threats include - time, history/maturation, regression to the mean, testing/instrumentation

Question 14

pretest/postest

Answer 14

used before/after an experience (with a control group) to determine if the difference is due to experience

Question 15

history

Answer 15

events between pre- and posttest that produces large changes unrelated to the program itself

Question 16

regression to the mean

Answer 16

an outlier score will most likely be followed by one closer to the average

Question 17

Instrumentation is a problem when:

Answer 17

when the measuring instrument changes from pre- to posttest (ie easier post- might skew results)

Question 18

subject selection effects

Answer 18

if groups are not matching, subject selection effects occur (can’t be sure if results are due to subject effects or experiment)

Question 19

attrition

Answer 19

when subjects drop out of a test - subject mortality - a problem because it may be that a certain type of person is more likely to drop out, leaving the group different than at the outset

Question 20

choices made by experimenter to effectively test a hypothesis

Answer 20

• experimental components

- experimental validity

Question 21

hawthorne effect

Answer 21

can influence internal validity - reactivity: making observations can change observations

Question 22

external validity

Answer 22

does my research generalize to other populations, environments and times?