1. 851-0585-04L – Modeling and Simulating Social Systems with MATLAB
L – Modeling and Simulating Social Systems with MATLAB
Lecture 8 – Scientific Writing and Presentation of Results
Giovanni Luca Ciampaglia, Stefano Balietti and Karsten Donnay
Chair of Sociology, in particular of Modeling and Simulation
© ETH Zürich |
© ETH Zürich |

2. Lesson 8 - Contents Scientific writing. (*) Research questions.
Lesson 8 - Contents
Scientific writing. (*)
Research questions.
Interpretation of results.
Tips on visualization of results.
* thanks to Heiko Rauhut and Volker Grimm for providing content

3. Scientific Writing Clear, easy to read, concise, and precise.
Avoid metaphors; use examples instead.
Keep sentences short
Main purpose: communicate your work so that others can replicate it, modify it and object to it.
It is still a form of creative writing!
Create a narrative

4. The Hour Glass Structure

5. What are your research questions?
In the introduction of your reports, clearly specify the research questions, e.g.:
How does crime influence population growth?
Will the outcome change if mechanism A is changed to mechanism B in the model? How?
Are the results of the model reproducible if the complicated function f(x)=exp(x+y)+y2 is replaced by the simpler g(x)=x+y ?
In the “Results” section come back to your research questions.

6. Interpretation of Results
Interpretation of Results
Remember: Correlation does not imply causation
Do not over-interpret your results
Propose an underlying mechanism
xkcd.com/552

7. Correlation vs. Causality
Correlation: corrcoef(A,B) =
Causality: A correlates with B, but how does the causality look like? A C A B B A B A B

8. Visualization of Results
Visualization of Results
Graphical formats: use PDF or EPS in the print version. JPG (better PNG) just for quick visualizations
Increase the font sizes for readability: set(gca, ‘FontSize’, 16);
ALWAYS use labels on axes: xlabel(‘Time (s)’, ‘FontSize’, 16); ylabel(‘Number of Agents’, ‘FontSize’, 16);

9. Visualization of Results (2)
Visualization of Results (2)
Put a box around the figure: box on
Show grid: grid on
Use thicker lines: plot(x, y, ‘LineWidth’, 2);
Set axis limits: xlim(x0, x0); ylim(y0, y0);

10.
Example
As an example: Let us say that we have a project about simulating happiness of agents.
We have the result of 10 different simulation runs in y, and the corresponding time vector in x.
x = t0:dt:t1; y = [happiness values from simulation 1; happiness values from simulation 2; happiness values from simulation 10];

19. Phase Diagrams
To show how the result depend on two different parameters, phase diagrams can be used:
D. Helbing and W. Yu, PNAS (2009)

20.
Create Videos
It is helpful to illustrate your simulations with videos during your presentation:

21.
Project Report
Have a look at last year’s projects to make sure that you don’t repeat the same results!
Use the report template.
Try to explain your results well, as well as explaining your motivation behind the project.
If you have any problems or concerns with your projects, we are here to help you!

22. Final checklist A typical scientific report should include: Title
Abstract
Introduction
Materials / Methods
Results
Discussion
References
Appendix (if needed)
ReportTemplate.zip

23. Presentation schedule
Project presentation 15’ + 5’ (for Q&A)
3 days available:
Mon 13th 5 – 7 p.m. (6 slots)
Thu 16th 10 a.m. – 1 p.m. (9 slots)
Mon 20th 5 – 7 p.m. (6 slots)
Due date: Midnight of 2 days before your slot
Late submissions get ½ point automatic penalty
Submission by
Put [MATLAB] in the subject line!