T-61.271 Visualization project description
11. Comparing MDS methods

Autumn 2004

Read the project description carefully. Questions and comments can be sent to

General information

The purpose of the project work is to get hands on experience and deeper understanding on one specific area of the course. At the same time you will be forced to think on some of the more general issues that are confronted every time a visualization method is developed or used.

To complete the project you will probably need information that has not been discussed on the lectures or in the exercises. Most of the time relevant information can be easily found on the web, course books or in some cases references to articles will be given. If you have problems finding information on the subject please contact the lecturer or the assistant for hints and guidance.

The project work will be valid for one year after the original deadline.

General requirements

specific requirements

The goal of this project is to analyze how different MDS methods preserve the features of a known data set.

To pass the following should be done

  1. Use different MDS methods to project a data set
    ( http://www.cis.hut.fi/Opinnot/T-61.271/world_cart.dat ) on to a 2-dimensional plane. The data set contains the locations of the countries of the world in 3D coordinates. At least Sammon's mapping, basic metric MDS, non metric MDS, one other variation of metric MDS and PCA should be compared. You may also use some other suitable data set.

  2. Analyze the results. What kind of errors the different methods produced, what features were best preserved, which method worked best and why. What is the intrinsic dimensionality of the data? Do MDS and PCA agree? Are there any clusters in the data? If yes, how can you describe them? Are there meaningful directions on the visualization (2D-projection)?

    The report should describe the analyzes that you have made, the results and your thoughts on the methods uses.

Submitting the project work

The project work should be submitted by email to:


Tapani Raiko 2004-12-21