PSYC 230 UIUC CERTIFICATION SCRIPT 2026 QUESTIONS
WITH SOLUTIONS GRADED A+
● Sensation. Answer: The ability to detect a stimulus and, perhaps, to turn that detection into
a private experience.
● Perception. Answer: The act of giving meaning to a detected sensation.
● qualia. Answer: In philosophy, private conscious experiences of sensation or perception.
● dualism. Answer: the idea that the mind has an existence separate from the material world
of the body.
● Materialism. Answer: The idea that the only thing that exists is matter, and that all things,
including the mind and consciousness, are the results of interaction between bits of matter.
● panpsychism. Answer: The idea that the mind exists as a property of al matter- that is, that
all matter has consciousness
● psychophysics. Answer: The science of defining quantitative relationships between
physical and psychological (subjective) events
● two-lint touch threshold. Answer: The minimum distance at which two stimuli (e.g. 2
simultaneous touches) are just perceptible as separate
● just noticeable difference (JND). Answer: Also known as the difference threshold The
smallest detectable difference between two stimuli, or the minimum change in a stimulus that
enables it to be correctly judged as different from a reference stimulus.
● Weber fraction. Answer: The constant (K) of proportionality in Weber's Law. For weight:
1:40 Line length: 1:100
● Weber's Law. Answer: The principle describing the relationship between stimulus and
resulting sensation that says the JND is a constant fraction (K) of the comparison stimulus.
● Fechner's Law. Answer: A principle describing the relationship between stimulus and
resulting sensation that says the magnitude of subjective sensation increases proportionally to
the logarithm of the stimulus intensity - S = k log (R) S= psychological sensation R= physical
stimulus k= constant
, ● Gustav Fechner. Answer: - invented psychophysics - thought by some to be the true
founder of experimental psychology
● absolute threshold. Answer: The minimum amount of stimulation necessary for a person
to detect a stimulus 50% of the time
● Method of constant stimuli. Answer: A psychophysical method in which many stimuli,
ranging from rarely to almost always perceivable (or rarely to almost always perceivably
different from a reference stimulus), are presented one at a time. Participants respond to each
presentation: "yes/no," "same/different," and so on.
● Methods of limits. Answer: The magnitude of a single stimulus or the difference between
two stimuli is varied incrementally until the participant responds differently - The experimenter
begins with the same set of stimuli-- in this case, tones that vary in intensity. Instead of
random presentations, tones are presented in order of increasing or decreasing intensity. -
ascending: asked to report when tone is first detected - descending : report when tone is no
longer audible
● Method of adjustment. Answer: Similar to the method of limits, but the participant controls
the stimulus directly - subject is the one who steadily increases or decreases the intensity of
the stimulus
● Magnitude estimation. Answer: The participant assigns values according to perceived
magnitudes of the stimuli - EX: give observers series of sugar solutions and ask them to
assign numbers to each sample. - i.e. Solution 2 is 2x as sweet as Solution 1
● Stevens' power law. Answer: Magnitude estimates are well described by
________________ . - S = aI^(b) (S) is related to stimulus intensity (I) by an exponent (b) - A
principle describing the relationship between the stimulus and resulting sensation that says
the magnitude of subjective sensation is proportional to the stimulus magnitude raised to an
exponent. - exponent for brightness is 0.3, so change from 1 candle to 11 is quite dramatic,
but adding 10 to 100 results in only a modest change Adding 10 to 10,000 wouldn't even be
noticeable VS. Apparent length = 1.0 - exponent for electric shock is quite large (3.5),
meaning that the pain grows with I^(3.5), so a 4-fold increase in the electrical current is
experienced as a 128-fold increase in pain
● Weber's law vs. Fechner's law vs. Stevens' power law. Answer: Weber's law: involves a
clear objective measurement . We know how much we varied the stimulus, and either the
observers can tell that the stimulus changed or they cannot. Fechner's law: begins with same
objective measurements as Weber's, but the law is actually a calculation based on some
assumptions about how sensation works. - assumes that all JNDs are perceptually equivalent
WITH SOLUTIONS GRADED A+
● Sensation. Answer: The ability to detect a stimulus and, perhaps, to turn that detection into
a private experience.
● Perception. Answer: The act of giving meaning to a detected sensation.
● qualia. Answer: In philosophy, private conscious experiences of sensation or perception.
● dualism. Answer: the idea that the mind has an existence separate from the material world
of the body.
● Materialism. Answer: The idea that the only thing that exists is matter, and that all things,
including the mind and consciousness, are the results of interaction between bits of matter.
● panpsychism. Answer: The idea that the mind exists as a property of al matter- that is, that
all matter has consciousness
● psychophysics. Answer: The science of defining quantitative relationships between
physical and psychological (subjective) events
● two-lint touch threshold. Answer: The minimum distance at which two stimuli (e.g. 2
simultaneous touches) are just perceptible as separate
● just noticeable difference (JND). Answer: Also known as the difference threshold The
smallest detectable difference between two stimuli, or the minimum change in a stimulus that
enables it to be correctly judged as different from a reference stimulus.
● Weber fraction. Answer: The constant (K) of proportionality in Weber's Law. For weight:
1:40 Line length: 1:100
● Weber's Law. Answer: The principle describing the relationship between stimulus and
resulting sensation that says the JND is a constant fraction (K) of the comparison stimulus.
● Fechner's Law. Answer: A principle describing the relationship between stimulus and
resulting sensation that says the magnitude of subjective sensation increases proportionally to
the logarithm of the stimulus intensity - S = k log (R) S= psychological sensation R= physical
stimulus k= constant
, ● Gustav Fechner. Answer: - invented psychophysics - thought by some to be the true
founder of experimental psychology
● absolute threshold. Answer: The minimum amount of stimulation necessary for a person
to detect a stimulus 50% of the time
● Method of constant stimuli. Answer: A psychophysical method in which many stimuli,
ranging from rarely to almost always perceivable (or rarely to almost always perceivably
different from a reference stimulus), are presented one at a time. Participants respond to each
presentation: "yes/no," "same/different," and so on.
● Methods of limits. Answer: The magnitude of a single stimulus or the difference between
two stimuli is varied incrementally until the participant responds differently - The experimenter
begins with the same set of stimuli-- in this case, tones that vary in intensity. Instead of
random presentations, tones are presented in order of increasing or decreasing intensity. -
ascending: asked to report when tone is first detected - descending : report when tone is no
longer audible
● Method of adjustment. Answer: Similar to the method of limits, but the participant controls
the stimulus directly - subject is the one who steadily increases or decreases the intensity of
the stimulus
● Magnitude estimation. Answer: The participant assigns values according to perceived
magnitudes of the stimuli - EX: give observers series of sugar solutions and ask them to
assign numbers to each sample. - i.e. Solution 2 is 2x as sweet as Solution 1
● Stevens' power law. Answer: Magnitude estimates are well described by
________________ . - S = aI^(b) (S) is related to stimulus intensity (I) by an exponent (b) - A
principle describing the relationship between the stimulus and resulting sensation that says
the magnitude of subjective sensation is proportional to the stimulus magnitude raised to an
exponent. - exponent for brightness is 0.3, so change from 1 candle to 11 is quite dramatic,
but adding 10 to 100 results in only a modest change Adding 10 to 10,000 wouldn't even be
noticeable VS. Apparent length = 1.0 - exponent for electric shock is quite large (3.5),
meaning that the pain grows with I^(3.5), so a 4-fold increase in the electrical current is
experienced as a 128-fold increase in pain
● Weber's law vs. Fechner's law vs. Stevens' power law. Answer: Weber's law: involves a
clear objective measurement . We know how much we varied the stimulus, and either the
observers can tell that the stimulus changed or they cannot. Fechner's law: begins with same
objective measurements as Weber's, but the law is actually a calculation based on some
assumptions about how sensation works. - assumes that all JNDs are perceptually equivalent
