Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

Evaluation & Calculate Top-N Accuracy: Top 1 and Top 5

I have come across few (Machine learning-classification problem) journal papers mentioned about evaluate accuracy with Top-N approach. Data was show that Top 1 accuracy = 42.5%, and Top-5 accuracy = 72.5% in the same training, testing condition. I wonder how to calculate this percentage of top-1 and top-5?

Can some one show me example and steps to calculate this?

Thanks

like image 819
D_9268 Avatar asked Jun 07 '16 00:06

D_9268


People also ask

What do mean by evaluation?

Evaluation is a process that critically examines a program. It involves collecting and analyzing information about a program's activities, characteristics, and outcomes. Its purpose is to make judgments about a program, to improve its effectiveness, and/or to inform programming decisions (Patton, 1987).

What is an example of a evaluation?

Evaluate definition An example of evaluate is when a teacher reviews a paper in order to give it a grade. (math.) To find the numerical value of; express in numbers. To determine the importance, effectiveness, or worth of; assess.

What are the 3 types of evaluation?

The main types of evaluation are process, impact, outcome and summative evaluation. Before you are able to measure the effectiveness of your project, you need to determine if the project is being run as intended and if it is reaching the intended audience.


1 Answers

Top-1 accuracy is the conventional accuracy: the model answer (the one with highest probability) must be exactly the expected answer.

Top-5 accuracy means that any of your model 5 highest probability answers must match the expected answer.

For instance, let's say you're applying machine learning to object recognition using a neural network. A picture of a cat is shown, and these are the outputs of your neural network:

  • Tiger: 0.4
  • Dog: 0.3
  • Cat: 0.1
  • Lynx: 0.09
  • Lion: 0.08
  • Bird: 0.02
  • Bear: 0.01

Using top-1 accuracy, you count this output as wrong, because it predicted a tiger.

Using top-5 accuracy, you count this output as correct, because cat is among the top-5 guesses.

like image 132
rcpinto Avatar answered Oct 22 '22 21:10

rcpinto