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Questions tagged [precision]

Precision is about variability while (in contrast to precision), accuracy is about bias.

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Is it possible to estimate accuracy, precision and recall with the given data?

Background: I talked to my friend today and according to herm(him/her) I can calculate precision, recall and accuracy with the current information. Total instances T: 19,532. Instances belonging to ...
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Accuracy vs Precision: Can I use the Sphercity Assumption data in a meaningful way?

I understand that when conducting a repeated measures design with say one factor having three levels (Training: None, Standard, New Method), in the analysis you want the sphercity assumption to not be ...
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Precision vs. Accuracy when talking about MSE

This is more of a semantic question. I'm working on translating a work from French to English related to statistics. In French, there is only 1 word as far as I can tell to describe both bias and ...
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Acceptable Accuracy, Precision, Sensitivity, and Specificity Thresholds [duplicate]

Are there general rule of thumbs for acceptable accuracy, precision, sensitivity, and specificity values/thresholds in classification? I would imagine that this depends on different applications. I ...
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How to calculate ± deviation for precision and recall?

I found a precision and recall report table like as below Precision Recall .470±.009 .934±.013 .239±.010 .610±.013 I need the guidelines for ±.009 and ±.013 ...
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Highly unbalanced data set .Minority Class 1 %

I want to optimize precision and recall i.e f-score but I want to keep high precision . What are the possible ways of doing binary classification on such imbalanced data set [Minority class 1 %]. I'...
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28 views

accuracy and precision in regression vs classification

Are accuracy and precision the same things in regression and classification? In regression: accuracy is bias, and precision is inverse of variance. In classification: accuracy is correct prediction ...
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Calculating the number of true positives from a precision-recall curve

Using the below precision recall graph where recall is on x-axis and precision is on y-axis can I use this formula to calculate the number of predictions for a given precision, recall threshold ? ...
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Precision metric over a subset of classes?

I have a classification problem where I want to measure the precision over only a subset of classes. That is, for each time the model predicts a certain class within the subset, what is it’s precision?...
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130 views

The representation of F1-score on the Precision-Recall Curve

Is there a way to project the F1-score on the precision-recall curve for a such binary classifier? Is there a relationship between the area under the precision-recall curve and F1-score? ...
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which recall value to plot for same precision in PR curve?

Suppose, after sorting the true labels by the corresponding classifier scores, we obtain the following: $$[False, True, False, True, True, True, False, False],$$ which leads to the following points ...
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108 views

Rules of thumb for reporting precision for sample statistics

I'm curious about your thoughts on reporting precision for sample statistics. Are there good rules of thumb for this? For example, I'm reporting on $X$ and $Y$ which have $n$ samples. Statistics of ...
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117 views

Confidence in precision in the presence of few positives

I would like to report precision and recall for an existing binary classifier, which is a black box and which I cannot modify. I have a 1,000 test examples, sampled from a population of 100,000, and ...
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How do I call a forecast that is both accurate and precise?

How do I call a forecast (more precisely, a forecasting rule) that is both accurate and precise? Is there a word that expresses both properties combined? I do not mean the forecasting rule is perfect,...
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48 views

Half precision in batch normalization

Why is it a common practice to have single precision for batch normalization Even when the rest of the network is of half precision?
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71 views

How good is my recommender?

I implemented a recommender using tensorflow, based on e-commerce data. This recommender is predicting the next item a user will buy. I will judge the performance of my fitted model, by getting the ...
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After combining two sets of features, do we get averaged accuracy/recall/precision of two sets, or increased accuracy/recall/precision ?

I am working on IMDB review classification. With Tf-Idf and logistic regression, the f1-score is 0.87. With Doc2Vec and logistic regression, the f1-score is 0.8. When I concatenate the Tf-Idf matrix ...
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53 views

Effect size and power

I am a bit overwhelmed by all the information about effect sizes and power calculation here and I am not able to understand this. I have a protein from source A and B. They both highly correlate. ...
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187 views

Average of Precision and True negative rate as an accuracy metric

When attempting to construct a classifier for a somewhat imbalanced data set, I was led to the question of measuring the performance of the classifier. One of the first things I thought of was to take ...
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194 views

Choosing estimator based on Precision-Recall Curve

I hope you will help with this one. Below you see my Precision-Recall curves after performing 10-fold Stratified Cross Validation on my dataset. Note that my dataset is imbalanced that's why I'm ...
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307 views

Probability threshold and signal/noise ratio

I'm working on a classification problem in which the underlying signal to identify is very hard to find. I suppose that this is because the signal/noise ratio is very low. My questions are ...
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How would you validate a new test without a gold standard

Essentially: I am measuring a variable (continuous, unknown distribution) on a new assessment tool. There is no gold standard to compare to. I can take 2 measures per participant only. There is no ...
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How to account for imprecision of measurement used in clinical trial statistical testing?

Suppose an assessment used in a clinical trial is imprecise, i.e. given the same patient, two physician conclude different scores (but without bias). Also let's assume the level of imprecision is ...
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deduce variance from precision for bathymetry dataset

I mean to merge 2 gridded dataset of bathymetry using BLUE (Best Linear Unbiased Estimate). $merged = \frac{(\sigma_1^2 * dataset2 + \sigma_2^2 * dataset1)}{(sigma_1^2 + sigma_2^2)}$ I know the ...
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How to count precision and recall for multiclass classification which returns top-5 classes per test example

This is how testing looks like: There is 100 target classes The test set consists of 10K elements - each one of them is tagged by one target class The distribution of classes over test set is ...
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How to evaluate a Classifier model against the Ground Truth with missing labels?

I want to evaluate my classifier model (Facebook FastText) against the ground truth. My dataset has two labels let's say A and <...
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1answer
232 views

What exactly is the precision of an estimate?

What exactly determines the precision of an estimate (not estimator) from a finite, "real world" sample? I know there has been a similar question asked, but I think my question is different enough for ...
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59 views

How to decrease data precision correctly?

I have a set of experimental points with redundant precision: ...
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12k views

How to compute accuracy for multi class classification problem and how is accuracy equal to weighted precision?

Consider the example in this article http://text-analytics101.rxnlp.com/2014/10/computing-precision-and-recall-for.html Will accuracy be (30 + 60 + 80)/300? what is weighted precision?
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Measuring the size of a molecule with a ruler and enough independent measurements?

This question arose from the conversation on a previous question of mine. Also, I purposely came up with a ridiculous attention-grabbing title and question to facilitate the discussion more easily. I ...
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Why isn't instrumental/numerical precision classified as systematic error?

Sorry if my question is insultingly elementary, or if this isn't the right place to ask this. Though it's really just a matter of semantics, this question has been bugging me for quite some time. ...
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Are there parameters where a biased estimator is considered “better” than the unbiased estimator?

A perfect estimator would be accurate (unbiased) and precise (good estimation even with small samples). I never really thought of the question of precision but only the one of accuracy (as I did in ...
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1answer
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Network Equipment Availability and Significant Figures

looking for assistance in solving what I thought would be straightforward question but am struggling with. I monitor large numbers of Network gear including switches, routers and firewalls for ...
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Dirichlet-Regression: Indicator for variable fit in model comparison

I have a number of Dirichlet regression models with differing forms (log, linear, polynomial etc) over a dirichlet distribution of 6 variables/Groups. An examplary output for summary(fit) in r would ...
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Binary Classification: Is it possible to have high Precision for both classes and a bad overall Accuracy

I am trying to get my head around some results I recently obtained. I am looking at the Precision and overall Accuracy of two models on a classification task. Model A has better Precision than ...
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3k views

What is the difference between confidence intervals and precision?

I'm studying to be an auditor (CIA exam), but I do not have a statistics background and I'm very confused regarding the difference between confidence intervals and precision, then how they relate to ...
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379 views

Exactness of p-value in testing by simulation [duplicate]

When I use simulation to determine a p-value I am aware that the exactness of my p-value will be at most an estimate because I am using the scores of my sample and not my population, so that my ...
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454 views

Dice coefficient: what is the effect of a smoothing factor?

I've come across code to calculate a Dice coefficient in imaging segmentation, in which a "smoothing factor" was added to the formula, as below (pseudo-code): ...
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Meaning of Square Root of Covariance / Precision Matrices

Say $X \in \mathbb{R}^n$ is a random variable with covariance $\Sigma \in \mathbb{R}^{n\times n}$. By definition, entries of the covariance matrix are covariances: $$ \Sigma_{ij} = Cov( X_i,X_j). $$ ...
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Can you increase your number of significant digits by running multiple trials?

Suppose you have something you can easily measure many times but without the amount of resolution you need for an experiment. For example, if a reaction raises the temperature of a solution by 5 ...
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255 views

How to call the capture rate of the confidence interval

I have made a simulation study in order to evaluate the "efficiency" of a specific test method. I create some data and then I look whether the resulting CI of my my effect size estimate captures the ...
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2answers
788 views

Sample size Calculation for study with no prior information on proportion/sd

I came across to decide a sample size for a study. I searched online and looked into a bunch of formulas for different study design and objectives, and all of them need prior information from a ...
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1answer
58 views

Precision of Success

I have a setup where I am making X number of measurements over a particular time frame. These X measurements are success/failure measurements. For example, in the period of an hour I might get 422 ...
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1answer
6k views

What is the difference between accuracy and precision?

I read the material on the difference betweeen accuracy and precision, but it makes me feel confused. Can I define accuracy as: \begin{equation} accuracy=\frac{TruePositive+TrueNegative}{TruePositive+...
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What is an appropriate metric to optimize for when comparing different models for one-class classification?

Say I have a set of 100 positive and 1,000 unlabeled points. Among those unlabeled, some are presumably similar enough to the positives that they should belong to the positive class. Yet, if I ...
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2k views

How do you interpret the area under the precision-recall curve?

I recently learned of precision-recall curves as an alternative to ROC curves for testing the performance of a binary classification model. However, I don't know how to interpret the meaning of the ...
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1answer
130 views

R: Visualizing accuracy (inter-rater) on continuous data

Please excuse my english, I'm not a native speaker. So I'm running a test-retest scenario to determine accuracy of my measurements of continuous data (angles [deg] and length [mm]). I've calculated "...
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162 views

Increasing PR curve?

Usually PR curves are decreasing (like as precision decreases, recall increases). How would you justify/interpret an increasing precision recall curve? The only way I can explain this is that the ...
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41 views

How can I calculate ± estimate based on sample set?

Say I have a completely random sample of 25M weights of a population of 100M. Say the average weight of the 25M random sample is 150lbs with a standard deviation of 45lbs. How can I be more precise in ...
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260 views

Intrarater reliability test for a single subject?

I have repeatedly measured the volume of the brain of 1 subject in an MRI study. Measurements were acquired by the same rater (myself) on three separate occasions resulting in three measurements of ...