The precision-recall tag has no wiki summary.
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Unusual Precision-Recall Curve
Looking at precision-recall curves to evaluate an information retrieval system. Typically, these are done with a set of samples, with what users have picked out of a set of given items.
I have an ...
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1answer
22 views
Comparison of two classifiers based on prec/recall/F1 only?
For two classifiers h1 and h2 I have the precision, recall and F1 score as a percentage (along with the original labeled dataset tested on). If I had access to which samples each classifier classified ...
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Precision, Recall and area under ROC curve as sample size increases
The following is a question from an exam paper on evaluating the performance of search engines. To this day I looked in my text book and literally close to 50 web pages and I can't
find one convincing ...
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Calculating margin of error for precision and recall
I commonly calculate the precision and recall for information pulled from text but I'm not sure how to calculate the margin of error for those precision and recall values.
So for example, if I have a ...
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15 views
How to combine multiple recall-precision curves
I am trying to evaluate an object detection algorithm, I have 8 scenes over which I run a detector for a particular object, giving me 8 PR curves. I want to combine these in to one curve, however the ...
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9 views
Recall Precision curve, precision jumps at high recall [duplicate]
I am trying to plot a recall-precision curve for an object detection algorithm. In order to detect objects, I create a vote-map (2D histogram) in which object centres are voted for.
I then filter ...
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1answer
174 views
How to calculate recall-precision curves
I am trying to plot a recall-precision curve for an object detection algorithm. In order to detect objects, I create a vote-map (2D histogram) in which object centres are voted for.
I then filter ...
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92 views
How to compute precision for a multiclass problem?
I have a question about calculating precision on a multiclass problem. If the true positives of some actual class is 0, and its false negatives is also 0, then how to calculate its recall? In this ...
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1answer
197 views
calculating recall and precision confusion
I got 100 text, 9 labeled as + and 91 labeled as -. My classifier predicted, 45 as + and 55 as -
So I have been asking myself this question. Out of 45+ predicted text, how many are actually +: answer ...
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2answers
783 views
how to calculate precision and recall for multiclass classification using confusion matrix?
all, I wonder how to compute the precision and recall using confusion matrix for multi-class classification problem. In specific, one data can only be assigned with most probable class/label.
I like ...
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3answers
74 views
better precision worse recall
is it possible for an algorithm A to have a better precision but worse recall (or better recall but worse precision) than another algorithm B?
Although I know that precision and recall are different ...
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1answer
235 views
Precision - Recall: Graphical Representation
I'm a little bit confused with precision recall. I read some papers about recommender systems, where in the one paper they have a graphical representation and in the other papers they don't (they just ...
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125 views
Summary statistics of the precision-recall curve
From what I understand, one can use the AUC of the ROC curve as a summary statistic of the full curve.
Q1. Are there any similar summary statistics that one can use on a single precision-recall ...
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1answer
88 views
Significance test for classification systems
I have several classification systems which I want to compare. The way I evaluate each one of them is using precision, recall and f-score. I want to compare the performance of every two of them using ...
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1answer
498 views
How to interpret F-measure values?
I would like to know how to interpret a difference of f-measure values. I know that f-measure is a balanced mean between precision and recall, but I am asking about the practical meaning of a ...
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1answer
203 views
Weighted average of precision (or recall) of all classes?
How to compute the global precision given the precision calculated for each class? Is it just the average over classes precisions? When I use Weka the global precision is not computed as the average ...
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1answer
401 views
Precision and recall in a multi-class classification system?
Having looked at Wikipedia and looked around here, I'm still not clear how to identify the true positives, true negatives, false positives and false negatives in the multi-label classification problem ...
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3answers
299 views
Regarding precision and recall for the highly unbalanced validation data set [duplicate]
Possible Duplicate:
Optimising for Precision-Recall curves under class imbalance
I built a classification model and tested it against a validation data set. The positive set is composed of ...
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65 views
How to modify RankBoost to maximize area under recall-precision curve instead of AUC?
Using the WeakLearn algorithm from the original RankBoost paper, how do you set the optimal threshold to maximize AU-RPC (instead of AUC)? And, once that threshold is set, how do you calculate the ...
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2answers
1k views
Calculating precision and recall in R
Suppose I'm building a logistic regression classifier that predicts whether someone is married or single. (1 = married, 0 = single) I want to choose a point on the precision-recall curve that gives me ...
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3answers
127 views
What impact does increasing the training data have on the overall system accuracy?
Can someone summarize for me with possible examples, at what situations increasing the training data improves the overall system?
When do we detect that adding more training data could possibly ...
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2answers
182 views
Improving recall in a neural network
I built a neural net in Octave to predict if products are a match or not using a number of features. The net has 8 input features, 1 hidden layer with 8 nodes and outputs either match or no match. I ...
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2answers
131 views
Generalization and recall
I have some questions regarding generalization and recall:
It usually hear that a good classifier should "generalize" from the training data. Is that true?
I feel(?) that a "general" classifier ...
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1answer
184 views
Evaluating recommender systems with (implicit) binary ratings only
I'm analyzing a set of news articles and user libraries. User library is the set of news articles shared by one user. Obviously, the rating is 1 (the article is in user's library) and 0, otherwise. I ...
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1answer
277 views
Does it make sense to measure recall in recommender systems?
Assume I've built a recommender system that (given say movie rankings or whatever of many users) will produce a list of 10 recommended movies for each user to watch.
Imagine that I also have some ...
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1answer
322 views
Precision recall curve for nearest neighbor classifier
I am evaluating a multi class classifier. As precision and recall are only defined for binary classification I want to create precision recall curves for every class by separating one class from all ...
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0answers
121 views
Plot precision recall using a vector of ranks
I have developed a predictor which scores a datapoint, x on how likely it is to belong to a particular class, C. The higher the score the more likely it is that the datapoint belongs to the class.
...
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1answer
544 views
Optimising for Precision-Recall curves under class imbalance
I have a classification task where I have a number of predictors (one of which is the most informative), and I am using the MARS model to construct my classifier (I am interested in any simple model, ...
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3answers
5k views
How to compute precision/recall for multiclass-multilabel classification?
I'm wondering how to calculate precision and recall measures for multiclass multilabel classification, i.e. classification where there are more than two labels, and where each instance can have ...
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2answers
263 views
How to generalize precision, recall and F-score to non-classification problem?
I am working on a problem to predict a value between 0 and 1. The data is skewed, so that only 18% of the values are greater than 0.
I implemented a machine learning system, and what is happening is ...
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2answers
1k views
Increasing number of features results in accuracy drop but prec/recall increase
I am new to Machine Learning. At the moment I am using a Naive Bayes (NB) classifier to classify small texts in 3 classes as positive, negative or neutral, using NLTK and python.
After conducting ...
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1answer
144 views
What are other good ways of finding out the degree of similarity between lists?
I have a ground truth list, call it A, and I have different methods for generating lists that should be somewhat similar..
I want to decide which method of these generates a list that is most similar ...
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1answer
731 views
How to calculate 11 point interpolated standard recall precision? [closed]
I am actually not sure about the recall = 0 and recall = 1. I am trying to draw the recall vs precision curve. Interpolation is taking the max precision between two standard recall level.
I am ...
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2answers
216 views
How to sample clustering to estimate precision and recall?
There is a system containing $N$ clusters and in each cluster there are some elements. The clusters' sizes varies dramatically and most of the clusters are singletons.
I need to know the precision ...
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1answer
703 views
Precision and recall for clustering?
Im confused about calculating precision and recall for clustering mentioned in this paper (last paragraph of column 1 on page 5).
Suppose, if we are given with resultant cluster indicator matrix ...
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647 views
Evaluating and combining methods based on ROC and PR curves
I am evaluating and combining a few binary classification models. I am using the ROC and PR curves to evaluate their performance. The problem I am having is that as I try to improve the method, I am ...
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3answers
871 views
Calculating AUPR in R
It is easy to find a package calculating area under ROC, but is there a package that calculates the area under precision-recall curve?
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1answer
108 views
What are the correct edge case values of precision and recall and how to integrate them into cross validation?
I'm doing 10-fold cross validation on a dataset. But in some folds there are edge cases that the denominator in precision-recall calculation is zero (tp + fp =0).
What are the correct values for ...
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107 views
Why doesn't recall take into account true negatives?
Why doesn't recall take into account true negatives? In experiments where true negatives are just as important as true positives, is their a comparable metric that does take it into account?
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407 views
Should the mean precision and recall be weighted?
I have a bunch of experiments in which I am calculating precision and recall. I want to present a mean precision and recall for these experiments. Should these values be weighted by anything?
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1answer
500 views
What are correct values for precision and recall when the denominators equal 0?
Precision is defined as:
p = true positives / (true positives + false positives)
What is the value of precision if (true positives + false positives) = 0? Is it just undefined?
Same question ...
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2answers
575 views
How to choose a good operation point from precision recall curves?
Is there any standard method to determine an "optimal" operation point on a precision recall curve? (i.e., determining the point on the curve that offers a good trade-off between precision and recall)
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2k views
ROC vs precision-and-recall curves
I understand the formal differences between them, what I want to know is when it is more relevant to use one vs. the other.
Do they always provide complementary insight about the performance of a ...
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4answers
1k views
What are correct values for precision and recall in edge cases?
Precision is defined as:
p = true positives / (true positives + false positives)
Is it correct that, as true positives and ...
