QUESTIONS WITH SOLUTIONS GRADED A+
◉ 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
◉ Potential Confounding Variables: Environmental Factors. Answer:
There are other environmental factors that even in principle cannot
be held constant, but that can be balanced across the different
experimental conditions. These include the time of day, day of the
week, and month of the year when each student participates.
◉ 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