Section A carries 72 marks (42 marks for reporting values and 30 marks for interpretation).
Section A: Reporting Results – 42 marks (See Questions 1 – 3 & 5 & 8).
Section A: Interpretation – 30 marks (see Questions 4, 6, 7 & 9).
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
- The SPSS data on blackboard 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 Blackboard 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 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.
- 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].
- 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].
- 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].
- Using the same SPSS data file on Blackboard, 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].
- Summarise the highest order interaction and use the appropriate descriptive information to support your interpretation (e.g., means and/or mean differences). [250 words].
- 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].
- Produce an APA formatted Figure to display the data presented in Appendix A. [100 words].
- 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].
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 |
