PS4653: Research Methods and Statistics for Clinical Psychologists – CG4982: Research Methods in Counselling and Psychotherapy

PS4653: Research Methods and Statistics for Clinical Psychologists –
CG4982: Research Methods in Counselling and Psychotherapy

PS4653: Research Methods and Statistics for Clinical Psychologists –
CG4982: Research Methods in Counselling and Psychotherapy
Assignment Weighting = 60%
PS4700: Advanced Methods in Psychology
Research Design and Statistics Portfolio – Assignment Weighting = 40%

Section A: Factorial ANOVA and Interactions
Section B: Hierarchical Linear Regression
Assignment Deadline: 25th February 2022
– 16.59pm via Blackboard Link
Note: Please submit the assignment using the Blackboard submission link on your respective
module.
The assignment comprises two sections and assesses your understanding of quantitative
analyses (e.g. ANOVA & hierarchical regression). Please try to answer all questions – some of
these can be answered based on lecture materials and others require additional reading.
Engaging in additional reading will help to consolidate your understanding regarding this
assignment. Support your answers with references wherever possible. When presenting your
portfolio please label the two sections as indicated above and include the respective numbers for
questions. Present all your answers in a narrative – do not use bullet points otherwise marks
will be lost for that question. It is important to organise your time effectively in completing this
work to allow you to meet the deadline – and to gain support from staff during academic support
hours and taught sessions where needed. The questions will be easier to address once you have
engaged with the relevant lectures, the workshop and lecture tasks provided as well as additional
reading. You can use the taught sessions to raise questions that you may have about aspects of
the portfolio.
Section A carries 72 marks (42 marks for reporting values and 30 marks for interpretation).
Section B carries 28 marks (12 marks for reporting values and 16 marks for
interpretation/understanding). Marks are obtained for reporting descriptive information (means
and SDs) and statistics (ANOVA and regression values) – these marks are easier to obtain
than those requiring interpretation. For the questions that require interpretation/understanding,
more work will be required to gain these marks and additional reading will be key for these
questions.
Section A: Reporting Results – 42 marks (See Questions 1 – 3 & 5 & 8).
Section A: Interpretation – 30 marks (see Questions 4, 6, 7 & 9).
Section B: Reporting Results – 12 marks (see Questions 1 – 2).
Section B: Interpretation – 16 marks (see Questions 3, 4 & 5).
Note that you will receive an overall grade for the assignment, but the breakdown here should
guide you in how we assign marks.
Section A: Factorial ANOVA and Interactions
1. The SPSS data on Moodle are from a study that examined sentence reading times.
Sentences were either short (8 words per sentence) or long (15 words per sentence). The
second factor was space information – sentences either contained a space between each
word or the spaces were removed between the words. Sentence reading times were
recorded in milliseconds. Participants read the sentences under all conditions. All
participants completed a measure of spelling and vocabulary knowledge to explore the
effects of these two-between-participants variables on sentence reading times.
Conduct a three-way Factorial ANOVA on the data provided (see Moodle for SPSS
data file) using your two within-participants factors and include spelling group
(good versus poor spellers) as your grouping variable. You need to present an APA
formatted table of means and standard deviations showing the values for all levels of all
factors. Include a table number and a meaningful title and show consistency in reporting
decimal places. You can round up to two decimal places if you prefer or report to three
decimal places. See the example table on the lecture slides and Table 1 on this handout
for format. [100 words].
Table 1
Means (ms) and standard deviations (in parentheses) for target present and absent trials for
letters and digits in low and high working memory groups
Trial Types Letters Digits
Low Working Memory
Target Present Trials
Target Absent Trials
High Working Memory
Target Present Trials
Target Absent Trials
Note: This table is an example of how you should format the table for Question 1. You can copy
and paste this into your assignment to ensure that you have followed the correct format in line
with APA guidelines. The table title will need to be amended to fit in with the factors and levels
of the study described in Question 1 and heading names will need to be changed.
2. Report the results from the ANOVA you have conducted in a succinct narrative. Describe
the ANOVA conducted using the correct design notation and make it clear whether the
factors are between or within-participant factors. You must report the results for all effects
(3 main effects and 4 interactions) and ensure that they are all accurate to enable you
able to gain maximum marks for this question. Report the F ratio, degrees of freedom,
MSE, p value and effect size for all effects. Marks will be lost if reported as bullet points
– check lecture slides if you are unsure about the reporting. Please follow convention
when reporting p values – report p as either p < .001 (less than .001) or state the
exact p value. [250 words].
3. Introduce and present a table of means and means differences to show the descriptive
information for the space information x sentence length interaction. Follow the format
and example used in the lecture (e.g., arrange means from lowest to highest along
vertical and horizontal axis; compute mean differences for the comparisons
involved in the interaction). Conduct the Tukey HSD test by hand showing your
calculations in an Appendix and use this information to indicate the significant
comparisons in your table of means/mean differences (use an asterisk if they reach
significance). Report the results of your comparisons – you should refer to each
comparison along with the correct Tukey and p value for each effect. You should
interpret the direction of effects. [150 words].
4. Summarise the space information x sentence length interaction and use the
appropriate descriptive information to support your interpretation (e.g., means and/or
mean differences). [250 words].
5. Using the same SPSS data file on Moodle, conduct a three-way Factorial ANOVA using
the same within-participants factors, but this time enter vocabulary group (good
versus poor vocabulary) as your between-participants factor. Once you have
inspected your output, conduct the appropriate t-tests to follow up your highest order
significant interaction. Ensure you make it clear what type of tests you have conducted
(independent/paired t-tests) and the comparison that each t-test refers to along with a
statement of direction (you can use means and SDs to support this). [150 words].
6. Summarise the highest order interaction and use the appropriate descriptive information
to support your interpretation (e.g., means and/or mean differences). [250 words].
7. Summarise the descriptive data provided in Appendix A – you should outline whether
any of the patterns are consistent with an interaction and note your reasons for this.
You will want to use the respective means to support your answer. [350 words].
8. Produce an APA formatted Figure to display the data presented in Appendix A. [100
words].
9. Provide a brief discussion of the importance of power calculations when designing
experimental studies. This should include comments related to underpowered and
overpowered studies and be supported with evidence from the literature. You might
consider Type I and Type II errors in your answer. [300 words].
Section B: Hierarchical Linear Regression
The SPSS data file on Moodle includes variables from a study on problem gambling
(criterion) measured using a self-report inventory. Several predictors of problem gambling
were explored including age, emotion regulation, impulsivity, polydrug use and working
memory. (see Appendix A). Participants also completed a measure of full-scale IQ.
1. Conduct a hierarchical multiple regression analysis to explore the impact of the
predictors on problem gambling. Enter problem gambling as the criterion, and on step
1 enter impulsivity, emotion regulation and age as predictors. On step 2, enter working
memory and polydrug use as predictors and then enter FSIQ as the predictor on your final
step (step 3). You must enter the predictors as stated. Report the results in a
narrative (this should include an introduction to the analysis – stating the criterion and
predictors entered). Ensure that you report the results from the ANOVA model for all
steps of the analysis and comment on the percentage of variance explained as well
as the F change statistics and extra variance explained on subsequent steps.
Include the beta values for all models. [400 words].
2. Present an APA formatted table to show the B, SE of B and Beta values for your data.
Remember to number the table and to provide an appropriate/meaningful table title.
[150 words].
3. Provide an interpretation of your results – explain what beta values represent and
interpret the beta values for your results for all steps of the analysis (see lecture
slides). What do the beta values show for this study? [250 words].
4. Supporting your answer with references, provide a brief discussion of Cook’s distance
and hat values. Explain what these terms mean and why they are important to consider
in regression analysis. [300 words].
5. Explain the difference between hierarchical and stepwise regression and outline the
strengths and limitations of these analyses. You should support your answer with
references. [300 words].
Note: All work is marked in line with our assessment and moderation procedures to ensure
consistency across markers, and only returned once the moderation process is complete. All
grades are provisional until confirmed at the exam board.
Appendix A: Descriptive Data – Question 7
A psychologist conducted a study to investigate differences in sustained attention among
adolescents and adults diagnosed with attention deficit hyperactivity disorder (ADHD) relative to
a control group. Ninety participants (n = 30 in each group) completed a sustained attention task
on three separate occasions (Day 1, Day 2, Day 3) in which they responded with a button press
to digits appearing on a computer screen. Participants were instructed to withhold their
response when the digit was accompanied by an asterisk. Response times were recorded
along with accuracy scores (proportion of trials in which they successfully withheld a response).
The data from their response times are presented in Table 1. A 3 (group) x 3 (time) mixed
ANOVA was conducted to establish if sustained attention performance changed over time as a
function of group. Table 1 displays the means for sustained attention response times for all
groups for Day 1, Day 2, Day 3.
Table 1. Mean response times (ms) as a function of group and time.
Group Day 1 Day 2 Day 3
ADHD Adolescents 500 460 458
ADHD Adults 400 390 388
Controls (No ADHD) 340 280 240
Appendix B: Summary of Measures used for Regression
Table 3. Summary of measures
Variable Name Measure Score
Problem gambling
(criterion)
Self-report High score shows more
evidence of problem
gambling
Impulsivity (predictor) Self-report Higher score shows higher
impulsivity
Age (predictor)
Emotion regulation
(predictor)
Self-report Higher score shows better
emotion regulation
Polydrug use (predictor) Self-report Higher score shows more
incidents of drug use
Working Memory
(predictor)
Digit Span
(forward/backward)
Accuracy score = higher
score shows better
performance
Full-Scale IQ WASI Standard score