2023-11-27 PSYC3900 Lab Exam 2

PSYC3900 Bitton Fall 2023 Lab Exam 2 Statistical Analyses Q1 – Before determining the impact of omega-3 levels on the cognitive abilities of young birds, you should confirm that their access to landfills indeed influences fatty acids level in their blood. Using the most complete model, determine if omega-3 fatty acids are influenced by the distance of nests from landfills, and their location (urban vs rural). A) Evaluate the assumptions you can with analyses under the ‘Regression’ tab in jamovi (no need to evaluate outliers for this question). If a statistical test for the assumption is available, reproduce the output AND report its result in a complete sentence. If only a figure can be produced to evaluate the assumption, reproduce that figure AND report its result in (a) complete sentence(s). B) Do not reduce the model, report the results from the omnibus test using (a) complete sentence(s). In this sentence, report the proportion of variance explained by the complete model, and include the test statistic (with appropriate degrees of freedom) and p-value for each term. Reproduce (copy/paste) your omnibus table. C) Produce the figure that best demonstrates the relationships between omega-3 fatty acids as a function of distance and location. D) What inferences can you make from your statistical results based on the trends observed in the figure? /14 Q2 – Your next step is to investigate if various measures can predict if the young crows succeeded in solving the puzzle box. Specifically, you are interested in determining if the mother ’s age and cognitive abilities, in addition to the young crow’s age and omega -3 fatty acid blood levels can predict success at solving the puzzle box. You decide to use the appropriate test, without interactions. A) Before you look at your model, evaluate the relationships between the independent measures. Report the results in (a) full sentence(s) that includes the appropriate test statistics and p-values. Reproduce the appropriate table(s) of results and the associated figure(s). B) Build the model to predict puzzle box solving success, and test the assumptions you can (using only statistics) within the test menu. No need to evaluate outliers for this question. Report your evaluation of the assumptions in a complete sentence with appropriate test statistic(s). Reproduce the appropriate table(s). C) Reduce the model until only significant terms are included. Report the results using a complete sentence. In this sentence, report the proportion of variance explained by the final model, and include the test statistic(s) (with appropriate degrees of freedom) and p-value for each term. Reproduce the table with model fit and coefficients. D) Produce the figure that best demonstrates the relationships between the puzzle box solving success and the terms included in the final model. E) Discuss in a sentence or two how good the final model is at classifying (predicting) the puzzle solving abilities of the young crows. Reproduce the appropriate table(s). F) What kind of inferences regarding the impact of landfills on cognitive ability can you draw from these results? Discuss in one or two sentences. /22 Q3 – Finally, you are interested in determining what influences the size of the young crow’s frontal cortex. As predictors, you are interested in the distance from a landfill, the location (rural or urban areas), the age of the young crow, and the blood concentration of omega-3 fatty acids. The model you are interested in testing does not include any interaction. A) Evaluate the assumptions you can with analyses under the ‘Regression’ tab in jamovi (no need to evaluate outliers for this question). If a statistical test for the assumption is available, reproduce the output AND report its result in a complete sentence. If only a figure can be produced to evaluate the assumption, reproduce that figure AND report its result in (a) complete sentence(s). B) Reduce the model until only significant terms are included, and