Name: __________________
ID: _____________________
Lecture Instructor: __________________
Section: _____________________
PSYCH 3320: Caffeine Lab Report Marking Guide
Kwantlen Polytechnic University
Psychology lab
Introduction (5 pts):
1: The task used in your experiment was used to assess cognitive functioning within a specific domain. What domain of
cognition was this task supposed to assess (1 pt)? Do you think this task is a valid measure of cognition within this
domain? Explain why/why not (1 pt)!
Many answer are acceptable for this section. Depending on the task chosen for the report, different domains of cognition
will be assessed. Some potential choices are summarized as paraphrased from the lab worksheet

Speed of information processing and fine motor control through a typing speed test

Planning and problem solving through the tower of Hanoi problem

Visual attention and processing speed through a visual search test

Impulse control and reaction time through the go/no-go task
Other domains are acceptable as long as they correspond well to the dependent variables for each task. For full marks,
the chosen domain can be explained by describing why cognition in this domain can be operationalized using each task.
Alternatively, students may choose to critique the task and argue that it does NOT do a good job of assessing cognition
within X domain.
2: The experiment you participated in had an independent variable (i.e. a factor that was altered between two or more
conditions to test the effect of something) as well as at least one dependent variable (a factor that was not manipulated,
but rather, was measured to determine the effect of changes in the independent variable). In this experiment, what was
the independent variable? (1 pt) What was/were the dependent variable/s? (2 pts) Please state the independent
variable in a way that encompasses ALL of the different experimental conditions resulting from changes in the
independent variable. Also, please be as specific and detailed and possible when defining your dependent variable/s (i.e.
it/they should be exactly what was measured in the experiment).
For all tasks, the independent variable is the same – how much caffeine each participant consumes when reattempting
the task for a second time (0 mg, 100 mg, 200 mg, or 300 mg).
The dependent variables are different for each task, but each task has two independent variables:

Speed Typing Task:
o
Difference in typing speed (words per minute) between first attempt (no caffeine) and second attempt
(variable amount of caffeine consumed 1 hour prior)
o
Difference in total number of typing errors made between first attempt (no caffeine) and second
attempt (variable amount of caffeine consumed 1 hour prior)

Tower of Hanoi Problem:
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o
Difference in total amount of time (seconds) required to move all of the rings in the correct order to the
correct peg between first attempt (no caffeine) and second attempt (variable amount of caffeine
consumed 1 hour prior)
o
Difference in number of moves required to move all of the rings in the correct order to the correct peg
between first attempt (no caffeine) and second attempt (variable amount of caffeine consumed 1 hour
prior)

Visual Search Test:
o
Difference in average reaction time (milleseconds) between first attempt (no caffeine) and second
attempt (variable amount of caffeine consumed 1 hour prior)
o
Difference in accuracy (expressed as a decimal value) between first attempt (no caffeine) and second
attempt (variable amount of caffeine consumed 1 hour prior)

Go/No-Go Task:
o
Difference in average reaction time (milleseconds) between first attempt (no caffeine) and second
attempt (variable amount of caffeine consumed 1 hour prior)
o
Difference in percent correct responses to green circular stimuli between first attempt (no caffeine)
and second attempt (variable amount of caffeine consumed 1 hour prior)
Answers which have the correct measures for the dependent variable but fail to acknowledge that the dependent
variables are difference scores will only receive 1 out of 2 points.
Results (8 pts):
1: The results for the experiment you are reporting on should be presented in the form of a bar graph. For each dependent
variable studied, you should provide a separate graph! Tutorial videos for graphing data using Microsoft Excel can be
found at: https://www.kpu.ca/arts/psychology/bscpsychlab
Each graph should include the following:


A title which accurately describes the graphed data (1 pt)
Descriptive x and y axis titles which, respectively, allow readers to understand which data belongs to
which experimental condition, as well as the meaning of any numerical data presented (1 pt)

Bar columns corresponding to mean values of the dependent variable for each condition (1 pt)

A written/verbal summary of the results, including exact mean values obtained by students from the class
for each condition (1 pt)
Marking criteria for each graph is self-explanatory. See above. There should be two graphs included – one for
each dependent variable (each task measured two different dependent variables).
Discussion and Critical Thinking Questions (11 pts):
1: Based on the results graphed in the previous section, how would you characterize the effect observed in this
experiment (2 pts)? If there are multiple dependent variables, be sure to discuss the effects of each dependent variable
Kwantlen Polytechnic University- Psychology Lab
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separately. Also, your characterization should make reference to specific variables, and discuss the both the
presence/absence and direction of any observed effects.
Correct answers will vary depending results obtained by the class for each task.
2: Using a literature source as support, please provide a biological explanation for the effects that you
characterized (3 pts). Your literature source should be from a peer-reviewed journal, and should NOT be one of the four
articles already cited in the lab worksheet (although they may be a useful starting point for you to conduct your research).
A well-written explanation should include a concise summary of the literature material, a correctly formatted APA 6
style in-text citation, and a logical biological explanation that uses the information from your literature source to account
for our experimental results. For more resources on using APA 6 formatting, see the following

KPU Library Website: http://libguides.kpu.ca/apa

Purdue Online Writing Lab: https://owl.english.purdue.edu/owl/resource/560/02/
This is a challenging question. Many responses are possible depending on the sources used, results obtained, and
explanations offered. The assignment description offers a good framework of the three elements which should be present
in this answer – (1) a brief summary of the literature source (or part of the literature source relevant to the author’s
explanation), (2) an APA 6 in-text citation, and (3) a biological explanation for the results observed. If all of these
elements are present and well-executed, full marks will be awarded. If any of these elements are present but are executed
with some problems, partial marks will be awarded for that element.
3: When participants were assigned to experimental conditions, those who did not ordinarily consume caffeine for
various reasons (e.g. health concerns, religious obligations, et al.) were sorted into Group 1 (which re-attempted each
computerized task after consuming no caffeine). Assuming people usually develop a tolerance to caffeine’s cognitive
effects within any cognitive domain over time, how would this methodological choice most likely affect our
experimental results? Why would this be the case? (2 pts).
If we assume that people usually develop a tolerance to caffeine’s cognitive effects within any domain, then this (ethically
sound) methodological choice would most likely REDUCE the magnitude of any cognitive effects of caffeine we observe
(assuming any exist). Tolerance refers to the phenomenon where chronic use of a psychoactive substance over time
reduces the intensity of that substance’s effects. In this experiment, caffeine-naïve participants would likely experience
more dramatic caffeine-induced changes in cognition compared to chronic caffeine users (because caffeine-naïve
participants haven’t built up a tolerance to caffeine’s effects).. However, these potentially dramatic caffeine-induced
changes in cognition can’t be observed in our experiment if caffeine-naïve users aren’t reattempting each task after
drinking coffee.
4: During the initial testing period, we did not measure or control the amount of caffeine consumed by participants prior
to class. Explain how this would this affect our ability to draw conclusions from our experiment and why this is
the case. If this experiment were to be repeated, what would be a methodological improvement that would solve
this issue? Explain how it would work (2 pts).
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The validity of the experiment relies on the assumption that there was, in fact, no caffeine consumed prior to the initial
testing phase for all of the tasks. However, since we didn’t measure or restrict caffeine intake prior to this testing phase,
we could be wrong in assuming that we are truly measuring the difference between each participant’s cognitive
performance in a caffeinated vs. non-caffeinated state. It may even be the case that some participants (particularly avid
caffeine drinkers) could have lower blood caffeine levels during the experimental re-attempt than they did during the
initial testing phase. Many methodological changes could fix this problem. One idea: a pre-screening questionnaire
eliminating potential participants who have consumed caffeine in the last 24 hours. Another idea: giving participants the
instructions for each experiment ahead of time before the initial testing phase so that they have time to restrict caffeine
consumption prior to completing the task for the first time. Many ideas are acceptable.
5: A pharmaceutical manufacturer is exploring the idea of selling different drugs which closely resemble the structure of
caffeine. One scientist presents the following three molecules as potential candidates
Molecule A
Molecule B
Molecule C
Based on your knowledge of caffeine, rank these three molecules in terms of how quickly they will be absorbed
after ingestion from 1 (absorbed the fastest) to 3 (absorbed the slowest). Justify your rankings (2 pts).
Molecule A = 2, Molecule B = 3, Molecule C = 1. As molecules becoming more non-polar (or more hydrophobic), they
will cross through lipid bilayers more easily, and thus be absorbed more quickly. As is highlighted in the lab worksheet,
bonds between nitrogen (N) and hydrogen (H) are more polarized than bonds between nitrogen (N) and methyl groups
(CH3), so for every N-H bonds replaced with a N-CH3 bond, an otherwise similar molecule becomes less polar, and is
thus absorbed more quickly from the digestive tract. Molecule B is xanthine, which has three N-H bonds, thus making it
the most polar and slowest absorbed molecule in this group. Molecule A has 2 N-H bonds and 1 N-CH3 bond, thus
making it slightly less polar and more quickly absorbed than xanthine. Molecule C has 1 N-H bonds and 2 N-CH3 bonds,
thus making it the least polar and most quickly absorbed of these three molecules.
6: FOR OPTIONAL BONUS MARKS, describe a new research question you could answer using the same task
you are reporting on (2 BONUS pts). For full credit, your response should (1) highlight the constructs being explored
in your research question, and (2) describe how each construct could be operationalized through a study design – be sure
to specify how you will measure any possible effects.
Many answers are possible as long as they include a decipherable research question, multiple conditions, and a good
description of how the results will be measured.
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Reference Section (1 pt):
Please include a properly-formatted APA 6 style reference section for the journal article you included earlier in the
discussion section. The KPU library website has APA resources available for you if you are experiencing confusion in
dealing with APA formatting. http://libguides.kpu.ca/apa
Full marks will be awarded for a correctly formatted APA 6 style citation. Formatting mistakes will result in the loss of
partial marks.
Writing Quality (3 pts):
The report should be written in clear, concise language (be as specific and detailed as possible) and free of grammatical
errors.
3 pts = The report contains few errors and is very easy to read and understand
2 pts = The report contains some errors throughout, which leads to some confusion for the reader. Clearer and more
specific language could improve comprehension
1 pt = the report contains many errors throughout and is extremely difficult to read. Incorrect or nonspecific terminology
is used. The report feels like a preliminary draft
0 pt = the report is unreadable and generally does not contain enough understandable content to convey any information
about the experiment to the reader
Data Submission/Lab Participation (12 pts):
You will receive (6 pts) for submitting data collected in-class (only data submissions from the original class period will
receive points) and an addition (6 pts) for submitting data from your at-home experimental re-attempt on time (students
who submit experimental re-attempt data after the July 6th due date will receive no points). Participation is very
important, since it improves the quality of the data for every student writing this report!
Total (40 pts):
Please note that lab reports should be submitted as word documents via email to BSc.psychlab@kpu.ca by 11:59 pm on
Wednesday July 16th at the very latest. Lab reports submitted later than this time will receive a 4-point deduction from
the final grade out of 40 for each late day. Please be sure to include your full name, student number, and course section in
the final submitted document (reports missing any one of these three vital pieces of information will receive a 1-point
deduction, regardless of whether this information is included in the email body or file name).
Finally, as insurance that your email has been received by the lab, I highly encourage you to include a read receipt
request from all submissions sent from outlook – this ensures you will be notified when your submission is received. In
the interest of fairness to students who complete the assignment on-time, submissions which do not reach the lab email
before the due date will still be considered late, even if the lateness is due to technological errors (message sending
failure, submission to an incorrect email address, etc.) rather than delayed completion of the work. If possible, please
complete the assignment early to leave time for potential technical issues (should they arise).
While I encourage you to collaborate and share ideas, each student must submit a separate lab report written in their own
words. Good luck! We are looking forward to reading your insightful interpretations and analysis!
Kwantlen Polytechnic University- Psychology Lab
Created: Summer 2014
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