Consider the fact that, if you live in a city, birds are essentially the only wildlife that you meet during your day.
Depending on where you live, you might come several species without even trying. In Vancouver, on my short 10 minute walk to work, I have a good chance to see rock doves, crows, mallars, wigeons, hooded mergansers (if I'm lucky), house sparrows, song sparrows, red-winged black birds, white-crowned sparrows, bushtits, black-capped chickadees, northern flickers, and the mother-of-all-honkers: Canada geese.
Birds and letters are everywhere—art of nature and man.
Letter forms, on the other hand, are the art that is also everywhere. Every typeface is an artistic expression.
Regardless where you live, sadly, you are likely to come across mutants like Comic Sans, Arial and Times New Roman. Hideous creatures from the shallows. Try to find Gotham, Gill Sans, Frutiger, or Garamond.
Mnemonics of bird songs help you remember the call and recognize the bird. It's so much easier to think "Quick, three beers!" — the call of the Olive-sided flycatcher — rather than "Chirp, chirp, chirp."
The mnemonic captures the cadence and repetition scheme of the song.
For example, if you listen to the white-throated sparrow you can't help but think that this little guy is trying to tell us something.
French Zonotrichia albicollis: Baisse ta jupe, Philomène, Philomène, Philomène. How differently we hear!
—Madelaine Lemieux (via Twitter)
Dear sweet Canada Canada Canada.
White-throated Sparrow (Zonotrichia albicollis)
American Goldfinch (Spinus tristis)
Here here. Come right here, dear.
Baltimore Oriole (Icterus galbula)
Who cooks for you?
Barred Owl (Strix varia)
Fire fire. Where where? Here here! See it, see it.
Indigo Bunting (Passerina cyanea)
Clear. Wick, wick, wick.
Northern Flicker (Colaptes auratus)
Quick, three beers!
Olive-sided Flycatcher (Contopus cooperi)
Where are you? Here I am.
Red-eyed Vireo (Vireo olivaceus)
Chubby chubby cheeks. Chubby cheeks.
Ruby-crowned kinglet (Regulus calendula)
Black-capped chickadee (Poecile atricapillus)
See me, pretty, pretty me.
White-crowned sparrow (Zonotrichia leucophrys)
If you love birds and typography, these posters are for you.
The mnemonic for the bird's song is presented on a background that proportionally presents the bird's plumage colors.
If you explore the posters, you just might find the bird too.
Quantile regression explores the effect of one or more predictors on quantiles of the response. It can answer questions such as "What is the weight of 90% of individuals of a given height?"
Unlike in traditional mean regression methods, no assumptions about the distribution of the response are required, which makes it practical, robust and amenable to skewed distributions.
Quantile regression is also very useful when extremes are interesting or when the response variance varies with the predictors.
Das, K., Krzywinski, M. & Altman, N. (2019) Points of significance: Quantile regression. Nature Methods 16:451–452.
Altman, N. & Krzywinski, M. (2015) Points of significance: Simple linear regression. Nature Methods 12:999–1000.
Outliers can degrade the fit of linear regression models when the estimation is performed using the ordinary least squares. The impact of outliers can be mitigated with methods that provide robust inference and greater reliability in the presence of anomalous values.
We discuss MM-estimation and show how it can be used to keep your fitting sane and reliable.
Greco, L., Luta, G., Krzywinski, M. & Altman, N. (2019) Points of significance: Analyzing outliers: Robust methods to the rescue. Nature Methods 16:275–276.
Altman, N. & Krzywinski, M. (2016) Points of significance: Analyzing outliers: Influential or nuisance. Nature Methods 13:281–282.
Two-level factorial experiments, in which all combinations of multiple factor levels are used, efficiently estimate factor effects and detect interactions—desirable statistical qualities that can provide deep insight into a system.
They offer two benefits over the widely used one-factor-at-a-time (OFAT) experiments: efficiency and ability to detect interactions.
Since the number of factor combinations can quickly increase, one approach is to model only some of the factorial effects using empirically-validated assumptions of effect sparsity and effect hierarchy. Effect sparsity tells us that in factorial experiments most of the factorial terms are likely to be unimportant. Effect hierarchy tells us that low-order terms (e.g. main effects) tend to be larger than higher-order terms (e.g. two-factor or three-factor interactions).
Smucker, B., Krzywinski, M. & Altman, N. (2019) Points of significance: Two-level factorial experiments Nature Methods 16:211–212.
Krzywinski, M. & Altman, N. (2014) Points of significance: Designing comparative experiments.. Nature Methods 11:597–598.
Celebrate `\pi` Day (March 14th) and set out on an exploration explore accents unknown (to you)!
This year is purely typographical, with something for everyone. Hundreds of digits and hundreds of languages.
A special kids' edition merges math with color and fat fonts.