Investigating Age and Speed of Information Processing Assignment

Assignment Task

1. Dr. Wise wants to know if people are slower in information processing as they get older. Illustrate this relationship between AGE and ‘Speed of information processing’ (SPEED) with a scatterplot with a line that illustrates the relationship (.25). Report this scatterplot, as a in APA format (.25), and describe the relationship (e.g., linear or not (.25), and the direction (.25) of the relationship). (Total 1 mark) (No Jamovi output required as this is used in )

2. Check if the observed relationship in Q1 is statistically significant or not by running a simple regression of AGE predicting SPEED (.25). Report on the result (.25), in APA format (.25), in terms of the F test and the amount of variance explained (i.e., R2 ) (.25). 

The Independent variable is Speed of Information Processing and the Dependent variable is Age. The relationship between the variables shows a moderate linear relation along with a negative direction.

A simple regression analysis was conducted to examine the relationship between age and speed. The F test showed that the relationship between age and speed is statistically significant (F = 157.94, p < .05). Additionally, the amount of variance explained by age in predicting speed was found to be R 2 = 0.44.

3. Say another researcher comes across your reported finding and wants to determine the sample size required to detect this effect (i.e., your zero-order correlation) with a power of .80. Calculate the minimum sample size required to replicate this finding in a future study if working out by hand or use the Excel spreadsheet from Tutorial 2 (Correlation) to show what formula was used. Assume α of .05). 

4. Produce a residual plot of the analysis in Q2. Report on your visual assessment of the presence of outliers (i.e., influential cases) and the criteria you have used in this visual assessment (.5 mark). Then determine if any data points are considered outliers based on the Mahalanobis distance equation. To do this, please use the code within the ‘Outlier code for assignment’ word doc. in the Assessment 2 resources folder on the LMS. The process to run the analysis is outlined in the simple regression tutorial) (.5 mark). 

5. Re-run the regression (AGE predicting SPEED) without these outliers (.25) and explain how the equation has changed, in APA format(.25), in terms of number of outliers excluded (.25), the change in sample size, F test result and the amount of variance explained (R2 ) (.25).

6. When looking at the subtest of information processing speed (SPEED), Dr Wise does not believe that ‘information processing speed’ would be predicted by the WAIS verbal subscales (v1 to v5). To test her conjecture, perform a standard multiple regression of v1 to v5 predicting SPEED (.25). Report on your findings, in APA format (.25), in terms of the F test and the amount of variance explained (i.e., R2 ) and then, in plain language, report if the results supported Dr Wise’s hunch or not (.50). 

7. Test if the Symbol Search subtest is a test of non-verbal ability by performing a standard multiple regression of p1 to p5 predicting SPEED (.50). Report the results in APA format (.50). Explain why you agree, or disagree, with Dr Wise’s opinion that the non-verbal data (p1 to p5) do not predict performance on the measure of information processing speed (SPEED). 

8. Produce a table of the multiple regression results (i.e., r, sr, β, t, p) of Q7, in APA format(.50). Report on how you determined which subtests were significant predictors of SPEED (.25) and comment on the relative contributions of these significant predictors (.25).

9. Looking at correlations and semi-partial correlations in Q8, explain why some performance subscales could be related individually with SPEED, but are not related when considered within a set of predictors of SPEED

10. Lastly, Dr Wise wants to examine if the performance subscales still significantly predicted SPEED, after controlling for age differences. Conduct this hierarchical regression (.50) and report the results (.50) in APA format (.50).

This Science has been solved by our PhD Experts at My Uni Paper.