2simpleexperiments Flashcards
Condition
One of the levels of the independent variable in an experiment
(design) Confound
Think order effects…. fatigue. that is a confound. another variable..?
systematic variability
In an experiment, the situation that occurs when the levels of a variable coincide in some predictable way with experimental group membership, creating a potential confound
unsystematic variability
In an experiment, the levels of a variable occurring independently of experi t l g b hi t ib ti g imental group membership, contributing to variability within groups.
selection effect
A threat to internal validity that occurs when the kinds of participants at one level of the independent variable are systematically different from those at the other level of the independent variable
random assignment
The use of a random method (e.g., flipping a coin) to assign participants into different experimental groups.
matched-groups design
An experimental design in which participants who are similar on some measured variable are grouped into sets and the members of each matched set are then randomly assigned to different experimental conditions.
between-subjects design
An experimental design in which different groups of participants are exposed to different l l f th i d d t i bl h th t h levels of the independent variable such that each participant experiences only one level of the independent variable independent variable.
within-subjects design
A study des g c eac pa t c pa t s design in which each participant ispresented with all levels of the independent variable.
posttest-only design
An experiment with an independent-groups design in which participants are tested on the dependent variable only once.
pretest/posttest design
An experiment with an id dnepenent-groups d i i hi h design in which participants are tested on the key dependent vari bl ae twi ce; once b f d f before and once afterexposure to the independent variable
partial-counterbalancing
A method of counterbalancing in which some, but not all, of the possible condition orders are represented.
Latin square:
A formal system of partial counterbalancing that ensures that each condition appears in each position at least once.
carryover effect:
A type of order effect that occurs when being exposed to one condition changes how people react to a later condition.
Practice effect
A type of order effect in which people s performance improves over time ‘s performance improves over time because they become practiced at the dependent measure (not because of the manipulation or treatment).
