Psych 255 QUIZ #3 Questions and
Correct Answers 2025-2026 Edition.
Experiment - Answer researcher manipulates one or more variables, tries to control
confounding third variables, and then measures how the manipulated variables affect
participants' responses
Experimentation - Answer Most beautiful "scientific work of art" because, if done correctly, it
is the best scientific tool we have to draw conclusions about causal relationships.
Experimental Control - Answer 1) manipulate one or more independent variables
2) choose the types of dependent variables that will be measured, and how and when they will
be measured, so that the effects of the independent variables can be assessed; and
3) regulate other aspects of the research environment including the manner in which
participants are exposed to the various conditions in the experiment
Casual Inference - Answer 1. Co-variation of X and Y
2. Temporal order: cause (X) before effect (Y)
3. Absence of alternative causes (confounds/third-variables) In principle, if X is the only factor in
a situation that varies prior to a change in Y, then the logical conclusion is that the variation in X
must have caused the change in Y.
Confounding variable - Answer is a factor that co-varies with the independent variable in such
a way that we can no longer determine which one has caused the changes in the dependent
variable.
Types of Variables (Review) - Answer Independent: the one thing you change, limit to only one
in an experiment ex) the liquid used to water each plant
Dependent: the change that happens because of the independent variable ex) the height or
health of the plant
Controlled: everything you want to remain constant and unchanging ex) type of plant used, pot
size, amount of liquid, soil type, etc
, What researchers hope to avoid: Systematic Bias - Answer in which the experimenter
consistently alters his or her behavior towards participants based on the particular condition
they are in
Single-factor design - Answer - has only one independent variable
- This IV must have at least (2) conditions, also called two levels of the IV.
- An experiment with 1 IV that has more than two levels is often called a single-factor, MULTI-
Level design
What determines how many levels of an IV we should create? - Answer Essentially, the
question about behavior that we ask, our personal preferences, and our assessment of available
resources will be three key factors.
Counterbalancing - Answer a procedure in which the order of conditions is varied so that no
condition has an overall advantage relative to the other conditions
Random assignment - Answer a procedure in which each participant has an equal probability
of being assigned to any one of the conditions in the experiment.
Between-subjects design - Answer different participants are assigned to each of the conditions
of the experiment
- researchers typically minimize the potential confounding effects of each subject by random
assignment
Advantages of between-subjects design - Answer 1) because each participant only engages in
one condition, effects caused by exposure to one condition (e.g., stress) can't carry over to
other conditions.
2) some scientific questions can only be examined using a between-subjects design
3) even when its possible to expose participants to every condition, doing so may require
developing different but equivalent versions of the same task, and it also may tip off
participants about the hypothesis being tested or true purpose of a study
4) Finally, there may be other reasons why it would be inadvisable to have each individual
participate in all the conditions.
Disadvantages of between-subjects design - Answer 1) although they usually are effective in
Correct Answers 2025-2026 Edition.
Experiment - Answer researcher manipulates one or more variables, tries to control
confounding third variables, and then measures how the manipulated variables affect
participants' responses
Experimentation - Answer Most beautiful "scientific work of art" because, if done correctly, it
is the best scientific tool we have to draw conclusions about causal relationships.
Experimental Control - Answer 1) manipulate one or more independent variables
2) choose the types of dependent variables that will be measured, and how and when they will
be measured, so that the effects of the independent variables can be assessed; and
3) regulate other aspects of the research environment including the manner in which
participants are exposed to the various conditions in the experiment
Casual Inference - Answer 1. Co-variation of X and Y
2. Temporal order: cause (X) before effect (Y)
3. Absence of alternative causes (confounds/third-variables) In principle, if X is the only factor in
a situation that varies prior to a change in Y, then the logical conclusion is that the variation in X
must have caused the change in Y.
Confounding variable - Answer is a factor that co-varies with the independent variable in such
a way that we can no longer determine which one has caused the changes in the dependent
variable.
Types of Variables (Review) - Answer Independent: the one thing you change, limit to only one
in an experiment ex) the liquid used to water each plant
Dependent: the change that happens because of the independent variable ex) the height or
health of the plant
Controlled: everything you want to remain constant and unchanging ex) type of plant used, pot
size, amount of liquid, soil type, etc
, What researchers hope to avoid: Systematic Bias - Answer in which the experimenter
consistently alters his or her behavior towards participants based on the particular condition
they are in
Single-factor design - Answer - has only one independent variable
- This IV must have at least (2) conditions, also called two levels of the IV.
- An experiment with 1 IV that has more than two levels is often called a single-factor, MULTI-
Level design
What determines how many levels of an IV we should create? - Answer Essentially, the
question about behavior that we ask, our personal preferences, and our assessment of available
resources will be three key factors.
Counterbalancing - Answer a procedure in which the order of conditions is varied so that no
condition has an overall advantage relative to the other conditions
Random assignment - Answer a procedure in which each participant has an equal probability
of being assigned to any one of the conditions in the experiment.
Between-subjects design - Answer different participants are assigned to each of the conditions
of the experiment
- researchers typically minimize the potential confounding effects of each subject by random
assignment
Advantages of between-subjects design - Answer 1) because each participant only engages in
one condition, effects caused by exposure to one condition (e.g., stress) can't carry over to
other conditions.
2) some scientific questions can only be examined using a between-subjects design
3) even when its possible to expose participants to every condition, doing so may require
developing different but equivalent versions of the same task, and it also may tip off
participants about the hypothesis being tested or true purpose of a study
4) Finally, there may be other reasons why it would be inadvisable to have each individual
participate in all the conditions.
Disadvantages of between-subjects design - Answer 1) although they usually are effective in
