evanmiller.org
Sample Size Calculator (Evan's Awesome A/B Tools)
http://www.evanmiller.org/ab-testing/sample-size.html
Evan's Awesome A/B Tools ( home. How many subjects are needed for an A/B test? Ndash; 13.2. The Minimum Detectable Effect is the smallest effect that will be detected (1-β)% of the time. Conversion rates in the gray area will not be distinguishable from the baseline. Statistical power 1−β:. Percent of the time the minimum effect size will be detected, assuming it exists. Significance level α:. Percent of the time a difference will be detected, assuming one does NOT exist.
evanmiller.org
A Taste of Rust
http://www.evanmiller.org/a-taste-of-rust.html
A Taste of Rust. May 14, 2015. Steve Klabnik has responded. To some of the issues I brought up here. It looks like I did not fully appreciate Rust’s optimization levels, among other things. When you’re done with this, go read his comments! The first etymology is an apocryphal IRC chat log. From the language’s creator. It is not made-up, at least not by me. Graydon I think I named it after fungi. rusts are amazing creatures. Graydon talk about over-engineered for survival. Jonanin what does that mean?
evanmiller.org
Evan's Awesome A/B Tools - sample size calculator, A/B test results, and more
http://www.evanmiller.org/ab-testing
Evan’s Awesome A/B Tools. Statistical calculators, ideal for planning. Read the full announcement ». Hellip;and if you like these, you'll love Wizard.
evanmiller.org
Ranking News Items With Upvotes
http://www.evanmiller.org/ranking-news-items-with-upvotes.html
Ranking News Items With Upvotes. July 14, 2015. As a follow-up to Deriving the Reddit Formula. Let's consider a social news website that lets users upvote items, but that doesn't permit them to downvote items. How can we infer the probability that a random user will upvote a story, given only the age of the story (t ) and the total number of upvotes (U )? Q = 1 - e {- lambda t} ]. This is one minus the (q ) from the previous model, which asked which fraction of users had. Seen a given story.). To form an...
evanmiller.org
Two-Sample T-Test (Evan's Awesome A/B Tools)
http://www.evanmiller.org/ab-testing/t-test.html
Evan's Awesome A/B Tools ( home. Does the average value differ across two groups? Confidence intervals and estimated difference. Sample 1 raw data:. Plusmn; 0.023. Plusmn; 0.031. SE = 0.023. Sample 2 raw data:. If the experiment is repeated many times, the confidence level is the percent of the time each sample's mean will fall within the confidence interval. It is also the percent of the time the hypothesis will be accepted (i.e., no difference detected), assuming the hypothesis is correct.
evanmiller.org
Swift Impressions
http://www.evanmiller.org/swift-impressions.html
June 4, 2014. Occasionally I have a good reason to pull an idea out of the queue and start writing a new computer program. Today marks one of those happy occasions. Apple announced a nifty new programming language called Swift. Hecate: The Hex Editor From Hell. Pronounced HECK-it, thanks for asking.). Anyway, I've been reading the Swift manual. At its core, the language is designed to eliminate bugs, but not in the academic way that, say, Haskell eliminates bugs by preventing normal people from writing c...
evanmiller.org
Deriving the Reddit Formula
http://www.evanmiller.org/deriving-the-reddit-formula.html
Deriving the Reddit Formula. July 13, 2015. A few things about Reddit's hot formula. Have always bothered me. The formula has obviously been a success when it comes to setting the Internet on fire, but I have to wonder:. Where do the seemingly arbitrary constants come from, and how do they effect the rankings? Why doesn't the current time appear in the calculation? Why is there a logarithm? What's with taking the absolute value of. When a Reddit visitor sees a story, she might have four reactions:. D = )...
evanmiller.org
Inferring Tweet Quality From Retweets
http://www.evanmiller.org/inferring-tweet-quality-from-retweets.html
Inferring Tweet Quality From Retweets. July 17, 2015. Here I want to develop a model to estimate a tweet's quality (percent of readers who will retweet it) that takes into account the passage of time, as well as retweeting behavior outside the author's immediate network. Can we come up with a formula for tweet quality using only the information that Twitter provides publicly? Modeling Tweets, Reads, and Retweets. Similar to Deriving the Reddit Formula. For clarity assume the original tweet occurred at ti...
evanmiller.org
Chi-Squared Test (Evan's Awesome A/B Tools)
http://www.evanmiller.org/ab-testing/chi-squared.html
Evan's Awesome A/B Tools ( home. Does the rate of success differ across two groups? Ndash; 13.4. Ndash; 13.2. If the experiment is repeated many times, the confidence level is the percent of the time each sample's success rate will fall within the reported confidence interval. It is also the percent of the time no difference will be detected between the two groups, assuming no difference exists. If you like this, check out Wizard. Mdash; the easy Mac statistics app.
evanmiller.org
Statistical Formulas For Programmers
http://www.evanmiller.org/statistical-formulas-for-programmers.html
Statistical Formulas For Programmers. DRAFT: May 19, 2013. Being able to apply statistics is like having a secret superpower. Where most people see averages, you see confidence intervals. When someone says “7 is greater than 5,” you declare that they're really the same. In a cacophony of noise, you hear a cry for help. Unfortunately, not enough programmers have this superpower. That's a shame, because the application of statistics can almost always enhance the display and interpretation of data. Conditio...
