Featured Research

from universities, journals, and other organizations

25 Years Of Conventional Evaluation Of Data Analysis Proves Worthless In Practice

Date:
September 5, 2008
Source:
Uppsala Universitet
Summary:
So-called ‘intelligent’ computer-based methods for classifying patient samples, for example, have been evaluated with the help of two methods that have completely dominated research for 25 years. Now Swedish researchers are revealing that this methodology is worthless when it comes to practical problems.

So-called ‘intelligent’ computer-based methods for classifying patient samples, for example, have been evaluated with the help of two methods that have completely dominated research for 25 years.

Now Swedish researchers at Uppsala University are revealing that this methodology is worthless when it comes to practical problems. The article is published in the journal Pattern Recognition Letters.

Today there is rapidly growing interest in ‘intelligent’ computer-based methods that use various classes of measurement signals, from different patient samples, for instance, to create a model for classifying new observations. This type of method is the basis for many technical applications, such as recognition of human speech, images, and fingerprints, and is now also beginning to attract new fields such as health care.

“Especially in applications in which faulty classification decisions can lead to catastrophic consequences, such as choosing the wrong form of therapy for treating cancer, it is extremely important to be able to make a reliable estimate of the performance of the classification model,” explains Mats Gustafsson, Professor of signal processing and medical bioinformatics at Uppsala University, who co-directed the new study together with Associate Professor Anders Isaksson.

To evaluate the performance of a classification model, one normally tests it on a number of trial examples that have never been involved in the design of the model. Unfortunately there are seldom tens of thousands of test examples available for this type of evaluation. In biomedicine, for instance, it is often expensive and difficult to collect the patient samples needed, especially if one wishes to analyze a rare disease. To solve this problem, many different methods have been proposed. Since the 1980s two methods have completely dominated research, namely, cross validation and resampling/bootstrapping.

“This has entailed that the performance assessment of virtually all new methods and applications reported in the scientific literature in the last 25 years has been carried out using one of these two methods,” says Mats Gustafsson.

In the new study, the Uppsala researchers use both theory and convincing computer simulations to show that this methodology is worthless in practice when the total number of examples is small in relation to the natural variation that exists among different observations. What is considered a small number depends in turn on what problem is being studied-­in other words, it is impossible to determine whether the number of examples is sufficient.

“Our main conclusion is that this methodology cannot be depended on at all, and that it therefore needs to be immediately replaces by Bayesian methods, for example, which can deliver reliable measures of the uncertainty that exists. Only then will multivariate analyses be in any position to be adopted in such critical applications as health care,” says Mats Gustafsson.


Story Source:

The above story is based on materials provided by Uppsala Universitet. Note: Materials may be edited for content and length.


Cite This Page:

Uppsala Universitet. "25 Years Of Conventional Evaluation Of Data Analysis Proves Worthless In Practice." ScienceDaily. ScienceDaily, 5 September 2008. <www.sciencedaily.com/releases/2008/09/080903101416.htm>.
Uppsala Universitet. (2008, September 5). 25 Years Of Conventional Evaluation Of Data Analysis Proves Worthless In Practice. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2008/09/080903101416.htm
Uppsala Universitet. "25 Years Of Conventional Evaluation Of Data Analysis Proves Worthless In Practice." ScienceDaily. www.sciencedaily.com/releases/2008/09/080903101416.htm (accessed August 21, 2014).

Share This




More Computers & Math News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Families Can Now Ask Twitter To Remove Photos Of Deceased

Families Can Now Ask Twitter To Remove Photos Of Deceased

Newsy (Aug. 20, 2014) — In the wake of a high-profile harassment case, Twitter says family members can ask for photos of dying or dead relatives to be taken down. Video provided by Newsy
Powered by NewsLook.com
Ballmer Leaves Microsoft's Board, Has Advice For Nadella

Ballmer Leaves Microsoft's Board, Has Advice For Nadella

Newsy (Aug. 19, 2014) — In a letter to Microsoft CEO Satya Nadella, Ballmer said he's leaving the board of directors and offered tips on how the company can be successful. Video provided by Newsy
Powered by NewsLook.com
What Google Can Gain From Special Accounts For Children

What Google Can Gain From Special Accounts For Children

Newsy (Aug. 19, 2014) — Google will reportedly offer official accounts for children younger than 13 years old. Video provided by Newsy
Powered by NewsLook.com
Breakingviews: Ebola's Economic Impact Could Eclipse SARS

Breakingviews: Ebola's Economic Impact Could Eclipse SARS

Reuters - Business Video Online (Aug. 18, 2014) — The virus ravaging Africa has yet to spread elsewhere. Yet Asia’s SARS crisis in 2003 showed how changes to behaviour can hurt the economy more than the actual disease, says Breakingviews' Una Galani. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins