UNSW PSYC3001 Research Methods 3 Assignment 2 – T1 2023 Dr Melanie Gleitzman & Dr Sonny Li
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School of Psychology
PSYC3001 – Research Methods 3 – T1 2023
Assignment 2
This assignment is due by 11pm AEST Monday April 17, 2023 (Week 10) and is worth 20% of your
final course mark. Submit your assignment to the Assignment 2 Submission Turnitin link on
Moodle in the Assignments section.
Please note:
• Assignments submitted after 11pm AEST Monday April 17, 2023 will incur a late penalty of
5% per day late. Assignments will not be accepted five working days after the deadline.
Feedback and comments may not be provided for late assignments.
• Special consideration requests to waive a late penalty are to be made online. Please See
https://student.unsw.edu.au/special-consideration.
• Marked assignments will be available from Turnitin after 10 working days from the
submission deadline. Late assignments will not be accepted under any circumstances once
assignments have been returned to students.
For this Exercise, your task is to:
1. Design a two factor between-subjects randomised experiment with two levels on one factor
and four levels on the other factor (i.e., a 2 × 4 design), and with at least 10 observations per
cell.
• Both factors should involve random assignment (i.e., factors should be chosen that allow
for participants to be randomly allocated to one of the J × K cells in the design).
• The dependent variable should be a continuous measure (with at least interval scale
properties). It can be a made-up measure or one referenced in the literature, either way
it should be a plausible measure.
• The design should allow for the examination of questions of interest to researchers in
some area of psychology.
2. Having designed the experiment (i.e., having decided on the nature of the factors and
levels), plan an appropriate set of contrasts for each factor (appropriate for your 2 x 4
factorial design).
• Your planned contrasts should include A and B main effect contrasts and AB product
interaction contrasts (appropriate for a standard factorial analysis; do not include
simple effect contrasts in your analysis). Your planned AB contrasts should be the
product of the A contrast with each B contrast.
• To satisfy the requirements above, you should make sure that each level of Factor B is
compared to one or more other levels of Factor B at least once within your set of B
main effect contrasts.
3. Make up a plausible set of raw data (scores obtained by participants on the dependent
variable), so that you have n observations in each of the JK cells of your design.
• Do not use data sets and research examples from PSYC3001 course materials. You are
being asked to make up your own design and data for this Exercise.
UNSW PSYC3001 Research Methods 3 Assignment 2 – T1 2023 Dr Melanie Gleitzman & Dr Sonny Li
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4. Carry out a planned standard factorial contrasts analysis, controlling the familywise error
rate at α = .05.
• Analyse your data using the PSY statistical program. Base your analysis on tests and raw
confidence intervals.
• In order to make your confidence interval inference more meaningful you should
propose a minimum difference in dependent variable units of theoretical or practical
importance.
• Your analysis must produce at least one significant main effect contrast and at least
one significant interaction contrast. What happens to the other contrasts is up to you.
Whatever the outcome, the results should be plausible.
• It is up to you as to whether or not each confidence interval corresponding to a
significant contrast establishes a theoretical/practical important effect.
NOTE 1: You may find that you need to modify the data in order to achieve the results you are
looking for. A very large F ratio for an individual contrast would usually indicate that MSE (mean
square error) is implausibly small, given the pattern of differences between means. For the
purpose of this exercise, an F of 100 or greater will be regarded as implausible.
NOTE 2: As you are asked to make CI inferences for your contrasts, this precludes including trend
contrasts in your analysis.
Write up of the Exercise (this is what you submit to Turnitin as a single document)
You should submit to Turnitin a single document that includes all of the following (in this order):
i. Your name and student ID number
ii. A brief description and rationale for the design, clearly stating the independent and
dependent variables and how these are to be operationalised.
iii. An account of the planned analysis, including a rationale for the planned contrasts chosen
for the analysis (i.e., why have you included these contrasts, in particular?)
iv. A clearly labelled table of A, B and AB contrast coefficients, identifying which contrasts are
included in your analysis (and make clear which levels of Factor A and Factor B each of the
JK coefficients refers to).
v. A summary of the data (including a clearly labelled table of means and plot of cell means).
vi. A summary of the outcome of your contrast analysis (both tests and raw confidence
intervals). State the decision rule used for tests. Include the PSY summary table and
formatted PSY confidence interval table (edited from PSY output to produce a single table
for A, B and AB contrasts).
Provide a concise interpretation for your contrast analysis (what does it all mean?). Your
interpretation should include directional and confidence interval inference.
vii. Appendix – include a copy of your PSY input file(s), and complete (unedited) PSY output
file(s) at the end of your assignment (as an Appendix). Include PSY output for each run
through PSY. Do not delete any part of the PSY output. Hint – paste PSY output into your
Word doc as Courier 10pt font. This will make sure the output has the correct spacing.
NOTE: Your Assignment cannot be marked unless your PSY analyses can be verified.
UNSW PSYC3001 Research Methods 3 Assignment 2 – T1 2023 Dr Melanie Gleitzman & Dr Sonny Li
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Make sure all your tables and graphs are clearly labelled.
Include in your report:
• table of contrast coefficients
• a table of cell means
• plot of cell means
• contrasts Summary table (as produced by PSY)
• Raw CIs table (edited from PSY output to produce a single table for A, B and AB
contrasts)
IMPORTANT – It is your responsibility to make sure you upload the correct document to the
Turnitin link (with the correct PSY input and output files included in the Appendix).
Note that no resubmission will be allowed after the deadline.
Length: The written part of your report (excluding tables and graphs and Appendix) should be no
more than about eight typed pages (1½ spacing).
Evaluation: Reports will be evaluated on the basis of:
• Rationale of the design. (Do your two factors make sense in combination with each other?
Are the levels of each factor sensible and appropriate to your research question?)
• Clear description of variables. (How is the DV measured? How are the factors and factor
levels operationalised?)
• Rationale for your planned contrasts.
• Plausibility of the data (Are the cell means and within-cells variability plausible, given the
nature of the DV and factors?)
• Correct execution of the planned contrasts analysis. Correct decision rule for tests? Have
CIs been correctly generated?
• Clarity and conciseness of the interpretation of the contrasts analysis.
Rambling or lengthy reports will not be highly regarded. You do not need to include a long
introduction or a literature review. If you wish to refer to one or two key references in the course
of showing the relevance of the design to (say) a theory, then by all means do so, but in most cases
this should not be necessary. Provide enough background information to enable the reader to
understand the logic of the design and how the variables were operationalised, but no more than
this.
How to Avoid Plagiarism and Student Misconduct
Do not use designs and data sets referred to in the PSYC3001 course materials (if you do, you may
receive a mark of 0).
The data for this Exercise should come from you (no other source). However, for inspiration in
choosing variables, you may refer to other Psychology courses or the psychology literature.
You are reminded that the work you submit must be your own and should not be the work of
another student (past or present) or any other person.
UNSW PSYC3001 Research Methods 3 Assignment 2 – T1 2023 Dr Melanie Gleitzman & Dr Sonny Li
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The best way to avoid plagiarism is not to put yourself in a situation where it may occur. Do not give
another student access to your assignment. Do not ask for another student’s assignment (“just to
have a look at how it is done”). Do not pay someone else to write your assignment and don’t
purchase and/or download an assignment from the internet and submit it as your own (both of
these actions will be considered serious student misconduct and could lead to you being excluded
from University).
Severe penalties (including failure in the course) may be imposed on students found guilty of
plagiarism and student misconduct.
You are encouraged to consult the University’s webpages on Academic Integrity and Plagiarism
https://student.unsw.edu.au/plagiarism for clarification of University policies and the
consequences for students who are caught plagiarising the assignment.
In particular, you should be aware that the University considers collusion to be one of the more
serious forms of plagiarism, and paying another person to complete your assignment is serious
student misconduct. The likely outcome for collusion is a 0 mark for the assignment, and the likely
outcome for serious student misconduct is failing the course (with the possibility of academic
exclusion).
For this assessment task, you may not use Generative AI. If the use of generative AI such as ChatGPT
is detected, it will be regarded as serious academic misconduct and subject to the standard
penalties, which may include 00FL, suspension and exclusion.