Chapter 10 - Simple Experiments

Question 1

define placebo group

Answer 1

control group that is exposed to an inert treatment, example being a sugarpill

Question 2

define design confound

Answer 2

a threat to internal validity in an experiment in which a second variable happen to vary systemically along with the independent variables, therefore create ana alternative explanation for the results

Question 3

define systemically variability

Answer 3

description of when the levels of the variables coincide in some predictable way with the experimental group, creating potential confound

Question 4

define unsystematic variability

Answer 4

description of when the levels of the variables fluctuate independently of the experimental group, contributing to variability

Question 5

define selection effects

Answer 5

treat to internal validity that occurs in independent-group design when the kind of participants at one level of independent variables are systemically different from those at other levels

Question 6

define matched groups

Answer 6

desgin technique where participants who are similiare are grouped into set, members are then randomaly assigned to conditions

Question 7

define independent-groups design

Answer 7

different groups are exposed to different levls of the varaibles

Question 8

define within-group design

Answer 8

particpants are presetned to all levels of the variables

Question 9

define posttest-only design

Answer 9

using independent-groups in which participatns are tested on the dependent variles once ONCE
-people are only in 1 control group
- only measure the dependent variable after the manipulation

Question 10

define repeated-measure design

Answer 10

where within-groups particpants respond to dependent variable more than one, after each exposure to the levels of independent
- particpants experince all levels of IV during same study adn teh DV is measured more than once

Question 11

define concurrent-measures design

Answer 11

where within-groups participants are exposed to all levels of independent at the same time and a single behavioural preference is the dependent
- all particpants experince all levels of IV at same time and make choice between two or more conditions
- DV is only measured once

Question 12

define order effects

Answer 12

threat to internal validity in which exposrue to one condition changes participants response to a later condition

Question 13

define practise/fatigue effect

Answer 13

where the participants performance improves over time due to practising the dependent measure or can be opposite for fatigue effect

Question 14

define carryover effect

Answer 14

a type of order effect, where some contamination carries over from one condition to the next

Question 15

define counterbalancing

Answer 15

presenting all levels of independent variable in different sequences to control for order effects

Question 16

define full and partial counterbalancing

Answer 16

full: where all possible conditons orders are represented
partial: only some of the possible conditions are represented (in radnom order or use latin square design)

Question 17

define manipulation check

Answer 17

extra dependent variable that can be included to see how well manipulation worked

Question 18

define pilot study

Answer 18

study completed before study of main interest, to test the effectiveness of the manipulations

Question 19

what is the differnce between independent group and within group designs?

Answer 19

indepndendent: also called between groups, posttest and pretest/posttest only designs

within: include concurrent and reapeated measures designs

Question 20

define pretest/posttest design

Answer 20

where the dependent variable is tested before and after the manipulation of the independent variable.
- to ensure that there is no difference in what is causes the dependent variable to change
- to inhance internal validity
- wanting to see that the change in independent is truly driven by the manipulation

Question 21

how to chose between post test and pre/post test design?

Answer 21

• if you have a large sample, you can be confident in random assignemnt and pre test is not necassary
• there are times where doing a pre test would give the hypothesis away to the participants

Question 22

what are the benefits of within groups designs?

Answer 22

the group are equivalent (no concern for over selection effects), can get more precise estimate as you are reducing noice (unsystematic variability) and you have a smaller sample size

Question 23

can you use within groups to test causal asocations?

Answer 23

covaraince: yes
temporal: yes
internal validity: yes but you need to be careful about order effects as design confound unique to these designs (carryover or practise/fatiqgue effects)

Question 24

define potential order effects

Answer 24

when exposure to all levels of IV can give the hypothesis away (demand characteristics)
- can sometimes be impossible to get back to baseline state