Psyc 5055 Foundations of Behavior Analysis
Name: ______________________________
Fall 2014
Class 5 Exam
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(1) Write your answers in the space provided under each question.
(2) Read the questions carefully and be sure to answer each as asked.
1) Describe how each of the following schedules of reinforcement differs in terms of how
reinforcement is arranged.
a) FI 30 seconds versus FT 30 seconds (2 pts) Both schedules require 30 seconds to pass before
reinforcement is available but the FI 30 requires a targeted response any time AFTER the 30
seconds to produce the reinforcement (responses during the 30 seconds are counted but have no
effect). The FT 30 delivers reinforcement every 30 seconds noncontingent on responding (no
target response is specified).
b) VR 50 versus FI 50 seconds (2 pts) VR50 is totally response dependent for reinforcement.
When the specified number of targeted responses occur (over time they average 50)
reinforcement is delivered immediately. FI50s is time and response dependent. After a fixed
time period of 50 seconds, the first targeted response is reinforced. Thus, every 50 seconds a
reinforcer is made available if a targeted response occurs any time after 50 seconds. Targeted
responses during the 50 second period have no effect.
c) VI 30 seconds versus CRF (2 pts) VI30s is time and response dependent while CRF is totally
response dependent. On VI30s, after a specified time interval has passed (over time these
intervals will average 30 seconds), the first targeted response will be reinforced. Targeted
responses during the intervals have no effect. On CRF, every targeted response is reinforced
after it occurs.
2) Describe how the response patterns produced by the following reinforcement schedules differ from
each other. (you can draw the typical cumulative records for each to clarify your description)
a) VR 50 versus a VI 50s (2 pts) VR 50 produces a high rate of steady responding with minimal
post reinforcement pausing. The VI 50s schedule also produces a steady rate of responding
with minimal post reinforcement pausing. The slope on the VI 50s is not as steep as the VR 50.
The rate of responding is lower (slower) in general.
b) FI 100s versus a FR 100 (2 pts). Both schedules will produce post reinforcement pausing
however the shapes of the curves will be different initially. The FI 100s will produce a
scalloping pattern where responding starts out slowly after a post reinforcement pause and gets
faster and faster as the interval gets closer to the end. The FR 100 has more of a break and run
pattern. There is a distinct pause in responding after reinforcement (the break) and when
responding starts it is constant at a high rate until reinforcement is delivered.
3) What is a PR schedule and describe how it might be used in an applied setting. (4 pts) PR is a
progressive ratio schedule where there is a series of fixed ratios that are systematically increased
usually after each reinforcement delivery. The highest ratio that the organism is able to complete is
called the break point. In applied settings these schedules are often used to test reinforcer
effectiveness (efficacy). Greater reinforcer efficacy will support higher break points. This can be
used in comparing drug effects, choosing which foods are most reinforcing, and/or which objects
will be most reinforcing.
4) When explaining the effects of reinforcement on rate of response there is a molecular orientation
and a molar orientation. What terms do each involve and how does each approach an explanation
to steady state response patterns? (4 pts) Molecular: IRT (inter response time) is the term for the
operant and the main unit of the analysis. Ratio schedules differentially reinforce short IRTs so you
have fast responding at high rates. Interval schedules differentially reinforce longer IRTs (if
Psyc 5055 Foundations of Behavior Analysis
Fall 2014
Class 5 Exam
organism responds slowly they still get the same amount of reinforcement then if they respond
quickly because the interval must pass before the response is reinforced). Molar: IRI (inter
reinforcement interval) is the term for the main unit of the analysis. Ratio schedules will produce a
shorter IRI with rapid responding (more reinforcers per hour) so they support higher rates. Interval
schedules have an IRI controlled by the interval length not the responses (as long as they make the
one response after the interval ends) so slower responding is reinforced. The rate will slow until
reinforcers are missed (waits too long after the interval has ended) so when reinforcer deliveries
per hour decrease below the scheduled value, responding increases to keep the reinforcement rate
as high as the interval schedule will allow.
5) Describe the experimental conditions that produced the effects Nevin referred to as “behavioral
momentum” in 1974. (4 pts) Two VI schedules, one very rich in reinforcement (frequent
reinforcers) and one very learn (infrequent reinforcers) alternate with time period in between with
nothing. Next introduce an interrupter (free food between the schedules or extinction in both
schedules or prefeeding before the session). The responding on the high reinforcement schedule is
less effected than the responding on the low reinforcement schedule. It has more “mass” and thus
more “momentum” to keep going longer when faced with disruptors.
a) How is this concept being applied today in applied work? (2 pts) This is useful in applied
settings to keep behavior going when disrupters are present (like less reinforcement). If we can
get behavior up to habit strength, the individual will continue with the appropriate behavior
during periods when the environmental support for this behavior is weak or the response effort
increases. For example we provide frequent reinforcement for complying with easy requests
and then when we make a request the client has failed to comply with in the past (the disrupter)
they are more likely to comply because “compliance behavior” has momentum.
6) From the Baum chapter, briefly give his main explanatory points related to “purpose as function”
(2 pts), “purpose as cause” (2 pts) and “purpose as feelings” (2 pts)
a) Purpose as function: The outcome of an act is its purpose. For example, the purpose of your
study behavior is getting 100% on the exam. This is a descriptive way to talk about purpose and
probably closest to a true scientific analysis because it emphasizes effects.
b) Purpose as cause: You should include his points about how we talk about future events as
causes for current behavior but since the future can’t “cause” the present we must invent a
present cause which is typically some hypothetical mental event (for example “I am driving to
the store because I have the intention of getting the seasoning I need for the meal I am cooking
this evening”. The invention is the “intention” as the cause of the driving.)
c) Purpose as feelings: You need to say something about feelings as self-reports about the future,
the past and as by-products of public situations. They occur at the right time to be used as a
cause. For example, a mentalist might say “I got the ice cream because I felt like it”. Baum
would say “I feel like I have in the past when getting ice cream was reinforced” (a reference to
feelings as self-reports of past contingencies). This means you could predict that you are more
likely to get ice cream in the future when certain feelings are noticed and that ice cream
reinforcement produces certain feeling as by-products.
7) What did Lowe discover about fixed interval scallops with different aged children and what was
his explanation for his findings? (4 pts) In almost all of the nonhuman animal studies, fixed interval
schedules produced a fixed interval scallop response pattern but with humans this pattern was the
exception rather than the rule. Lowe and his colleagues thought that with verbal humans their
language mediated the effects of the schedule to produce other patterns. Since the nonhuman
animals don't have language their patterns were due solely to the schedule. Lowe tested this with
preverbal humans and found fixed interval scallops similar to the nonhuman subjects. He reasoned
that the human learning history with other schedules and their verbal behavior combined to
Psyc 5055 Foundations of Behavior Analysis
Fall 2014
Class 5 Exam
produce the response patterns lacking the fixed interval scallop. There is some rat research which
showed that rats with an immediate history on variable ratio schedules did not show the fixed
interval scallop when switched to FI schedules.
************************* Bonus Points (answer with response pad) ********************
1) Online farming games often require the player to return after a certain amount of time to collect
their crop. If the player fails to check their crop within a specified amount of time after it is ready
for harvest will die and no longer “pay” when harvested. This is an example of:
a) limited hold
b) postreinforcement pause
c) break-and-run responding
d) behavioral momentum
2) The critical measure on progressive-ratio (PR) schedules is typically:
a) the rate of responding
b) the frequency of responding
c) the length of the postreinforcement pause
d) the breakpoint where the organism fails to complete the requirement
3) Mechner’s notation used in behavioral analysis describes ___________.
a) the consequence, not the response
b) the behavior of the organisms, not what the experimenter does
c) the response, not the consequence
d) what the experimenter does, not the behavior of the organisms
4) Infrequent reinforcement generates responding that is persistent, which is called the:
a) postreinforcement pause
b) molar maximizing
c) partial reinforcement effect
d) intermittent resistance