Course Organization & Course Organization & FormatFormat

Visualization IIVisualization IIMSIM 842, CS 795/895MSIM 842, CS 795/895

Instructor:Instructor:Jessica CrouchJessica Crouch

VisualizationVisualization

““A picture is worth a thousand A picture is worth a thousand words”words”

Visual communication can be Visual communication can be

very effectivevery effective

very efficientvery efficient if done wellif done well

Visual communication can be Visual communication can be

worthlessworthless if done poorlyif done poorly

Some visualizations are Some visualizations are more appealing and more appealing and informative than othersinformative than others

Course ContentCourse Content

The question:The question:– How can we design algorithms that How can we design algorithms that

produce produce informative, intuitive,informative, intuitive, graphical graphical representations of representations of datadata??

– No single answer exists (obviously)No single answer exists (obviously)

– Best design depends on Best design depends on Type of informationType of information What the user needs to learn from the What the user needs to learn from the

visualizationvisualization Efficiency considerationsEfficiency considerations

Assumption / Pre-Assumption / Pre-RequisiteRequisite Everyone here knows a bit about Everyone here knows a bit about

graphicsgraphics and has some experience and has some experience with graphics programming (OpenGL)with graphics programming (OpenGL)

What is the difference between What is the difference between graphics and visualization?graphics and visualization?

We’ll focus on We’ll focus on designing designing visualizations and visualizations and we’ll assume you have enough background in we’ll assume you have enough background in graphics to implement a design. graphics to implement a design.

– Background knowledge of graphics is important Background knowledge of graphics is important because issues of computational efficiency must be because issues of computational efficiency must be considered.considered.

– We could dream up NP-Complete algorithms that We could dream up NP-Complete algorithms that would produce lovely visualizations but would be would produce lovely visualizations but would be useless from a practical standpoint.useless from a practical standpoint.

– If a visualization needs to be interactive, If a visualization needs to be interactive, understanding how the graphics pipeline works is understanding how the graphics pipeline works is especially vital.especially vital.

Assumption / Pre-Assumption / Pre-RequisiteRequisite

Types of InformationTypes of Information

How should this course be organized?How should this course be organized?

Could categorize according to application Could categorize according to application area:area:– MedicalMedical– NetworksNetworks– OceanographicOceanographic– AstronomicalAstronomical– TransportationTransportation– Structural engineeringStructural engineering– Fluid mechanicsFluid mechanics– Etc.Etc.

Types of InformationTypes of Information

Often it is more useful to categorize Often it is more useful to categorize based on fundamental characteristics of based on fundamental characteristics of the datathe data

– DimensionalityDimensionality Inherent spatial coordinates?Inherent spatial coordinates? Time varying?Time varying? Scalar, vector, tensor properties?Scalar, vector, tensor properties?

– Sparse vs. denseSparse vs. dense

– Discrete vs. continuousDiscrete vs. continuous

Types of InformationTypes of Information

Visualization algorithms and techniques Visualization algorithms and techniques generalizegeneralize across application areas across application areas– Ex: Scalar fields can be visualized using color Ex: Scalar fields can be visualized using color

mappingmapping Works for temperature distribution over surface of Works for temperature distribution over surface of

the earth, for distribution of radiation over a slice of the earth, for distribution of radiation over a slice of the brain, and for the brain, and for lotslots of other applications of other applications

Course OrganizationCourse Organization

Visualization topics are roughly grouped Visualization topics are roughly grouped by data type by data type (with a couple exceptions)(with a couple exceptions)

Syllabus & tentative schedule are onlineSyllabus & tentative schedule are online

Assigned readings are online tooAssigned readings are online too– We’re reading We’re reading research papersresearch papers rather than a rather than a

textbooktextbook– Most classes will consist of a presentation Most classes will consist of a presentation

and discussion of 2 research papersand discussion of 2 research papers

Course FormatCourse Format

This is a Ph.D. level courseThis is a Ph.D. level course– No higher level courses in visualization are offered at No higher level courses in visualization are offered at

ODUODU– Objective is to familiarize you with up-to-date Objective is to familiarize you with up-to-date

visualization researchvisualization research– Focus will be on Focus will be on currentcurrent researchresearch

Will provide an opportunity for you toWill provide an opportunity for you to– Learn what is currently going on in the field of Learn what is currently going on in the field of

visualizationvisualization– Practice presenting research (even if someone else’s…)Practice presenting research (even if someone else’s…)

You need this for conferences, defense, jobs, etc.You need this for conferences, defense, jobs, etc.– Critically evaluating research workCritically evaluating research work

You’ll have to review other people’s papers and grant You’ll have to review other people’s papers and grant proposals, and you’ll need to know what to expect when proposals, and you’ll need to know what to expect when other people review your workother people review your work

Paper presentationsPaper presentations

Each student will present Each student will present two paperstwo papers during the during the semestersemester

First task: peruse the papers online and prioritize First task: peruse the papers online and prioritize them according to which ones you would prefer to them according to which ones you would prefer to presentpresent

Email me (jrcrouch@cs.odu.edu) your preferences Email me (jrcrouch@cs.odu.edu) your preferences by Sunday night.by Sunday night. In your email represent each In your email represent each paper using the letter labels given on the schedule.paper using the letter labels given on the schedule.

On Monday I will make assignments satisfying as On Monday I will make assignments satisfying as many preferences as possible and post the many preferences as possible and post the presentation schedule online.presentation schedule online.

First two presenters then have 9 days to prepare.First two presenters then have 9 days to prepare.

Course FormatCourse Format

Look at the website:Look at the website:www.cs.odu.edu/~jrcrouch/courses/msim842-s0www.cs.odu.edu/~jrcrouch/courses/msim842-s077

Write down username, password.Write down username, password.

How to prepare your How to prepare your presentationspresentations Read the paperRead the paper Read background material to clarify Read background material to clarify

anything in the paper that you don’t fully anything in the paper that you don’t fully understandunderstand– Look up some of the references from the end Look up some of the references from the end

of the paperof the paper– Use textbooks and other sources as Use textbooks and other sources as

necessarynecessary

Prepare a PowerPoint or pdf presentation Prepare a PowerPoint or pdf presentation and lecture to explain the paperand lecture to explain the paper– Send me your presentation file by 5pm Send me your presentation file by 5pm

Tuesday before your Wed. presentation.Tuesday before your Wed. presentation.

Presentation Presentation organizationorganization

Follow this Follow this general outlinegeneral outline when when preparing your presentation:preparing your presentation:

– ProblemProblem

– MotivationMotivation

– ApproachApproach

– EvaluationEvaluation

– ConclusionConclusion

– QuestionsQuestions

ProblemProblem

What problem does this work solve?What problem does this work solve?– Describe how the problem developedDescribe how the problem developed– If possible, tell the problem’s “story”If possible, tell the problem’s “story”

Ex., “New MRI technology was developed that reports Ex., “New MRI technology was developed that reports medically significant tensor data. Previous MRI data medically significant tensor data. Previous MRI data was scalar valued, so new methods for communicating was scalar valued, so new methods for communicating the structure of the tensor field in the brain needed to the structure of the tensor field in the brain needed to be developed. This paper describes a method for be developed. This paper describes a method for visualizing two dimensional tensors over the brain visualizing two dimensional tensors over the brain volume.”volume.”

– Give appropriate definitions of any new terms or Give appropriate definitions of any new terms or acronymsacronyms

This part should be interesting and attention This part should be interesting and attention grabbing (while remaining relevant)grabbing (while remaining relevant)

MotivationMotivation

Why is the problem important?Why is the problem important?– Examples of applications that would benefit Examples of applications that would benefit

from a solutionfrom a solution– Examples of people who might be able to Examples of people who might be able to

use a good solutionuse a good solution– Would a good solutionWould a good solution

Save lives?Save lives? Save money?Save money? Help scientists make new discoveries?Help scientists make new discoveries? Improve education?Improve education?

Tell us why should we care about this Tell us why should we care about this work.work.

ApproachApproach

Teach us how this visualization Teach us how this visualization method worksmethod works– Provide background information wherever Provide background information wherever

necessarynecessary– Go slowGo slow– Don’t skip stepsDon’t skip steps– Be explicit, give examplesBe explicit, give examples– Include illustrations from the paper and Include illustrations from the paper and

other sourcesother sources

This is the longest, most detailed part This is the longest, most detailed part of the presentationof the presentation

EvaluationEvaluation

How is the performance of this How is the performance of this visualization measured?visualization measured?– If a validation experiment was performed, If a validation experiment was performed,

explain how it worked: inputs, outputs, explain how it worked: inputs, outputs, comparisonscomparisons

Summarize the results of the Summarize the results of the evaluationevaluation– Put in context, given the what competing Put in context, given the what competing

visualization methods might dovisualization methods might do

ConclusionConclusion

In what situations would this method be In what situations would this method be ideal?ideal?

In what situations would this method In what situations would this method perform poorly?perform poorly?

Are the visualizations effective from a Are the visualizations effective from a human perception standpoint?human perception standpoint?

Is the method efficient from a computation Is the method efficient from a computation standpoint?standpoint?

Is additional work needed? If so, what?Is additional work needed? If so, what? This is the critical thinking part.This is the critical thinking part.

QuestionsQuestions

Bring 3-5 questions for the classBring 3-5 questions for the class– Ask us questions that require us to Ask us questions that require us to

thoroughly understand the paper in thoroughly understand the paper in order to answer.order to answer.

– Ask us questions that make us Ask us questions that make us consider the work critically and consider the work critically and stimulate discussion.stimulate discussion.

When you are not When you are not presentingpresenting Read the papers carefully before classRead the papers carefully before class

– Understand the basic objective and methods usedUnderstand the basic objective and methods used– Jot down questions regarding anything that is unclearJot down questions regarding anything that is unclear– Make note of what you think the main strengths and Make note of what you think the main strengths and

weaknesses of the work areweaknesses of the work are

Participate in class discussion of paperParticipate in class discussion of paper

Provide an honest and constructive evaluation of Provide an honest and constructive evaluation of your peers’ presentationsyour peers’ presentations– See form on course websiteSee form on course website– Fill out and give to me (or email me) after classFill out and give to me (or email me) after class– I will provide anonymous feedback to presentersI will provide anonymous feedback to presenters

Respond to feedbackRespond to feedback

No one will present two papers on No one will present two papers on the same day.the same day.

Please respond to Please respond to recommendations you receive on recommendations you receive on your first presentation when you your first presentation when you prepare your second prepare your second presentation.presentation.