forms - Interface for linking multiple email addresses and addresses to an account

In a web application I am building, I need to allow users to link multiple email addresses and addresses to their account.

The requirements are:

• Users can add and remove email addresses and addresses linked to their account.


• Users will need to set 1 email address and 1 address as their primary email/address.


• Adding addresses to the application is ENTIRELY optional, but the user must have at least 1 email address linked to the account (user log in using any of the linked email addresses).


• Adding and removing emails/addresses should be as quick as possible and having too many "pages" in the process is undesirable.


• Progressive enhancement is to be used. While we can easily create very rich and friendly experiences with the use of Javascript, an acceptable solution also needs to be avaliable for those without javascript.

Initially, I thought this would be something quite straight-forward and to simply use an "add/remove" control:

^{download bmml source – Wireframes created with Balsamiq Mockups}

The interface for editing addresses is exactly the same, except instead of 1 text field, we have multiple text fields and dropdowns representing a control for editing addresses.

Some apparent problems I have noticed:

Email addresses

• Do people ever need to edit an email address? For example, in Facebook, the currently linked addresses are not displayed in text fields and are just displayed as links:


• In my mock up, it is easy to mistakenly click the "make this primary" and "remove buttons".


• However, it is quite easy to mass edit and add new email addresses.

Addresses

• As it currently stands, the user will see a page full of text fields representing current addresses, which may or may not be confusing.


• The benefit is that users can easily modify all currently addresses and add and remove addresses all at once.


• Amazon has a similiar interface, but their add/edit address form is on an entirely seperate page:


• Unlinke Amazon, I do not need to allow users to set whether the address appears in the drop down or to link a payment method with the address.

Given these set of requirements and the pros/cons I have outlined, is there anyway to improve upon the interface to enhance the user experience? Or am I looking at the wrong approach and should be looking at a totally different way to do this?

Answer

I think the Facebook solution you presented is a better solution than your mockup for the following reasons:

1. As you mentioned, users shouldn't ever need to edit their email address; they will have received a confirmation link to that address, and so the email cannot be reasonably edited after the fact


2. The Facebook option makes it very easy to see which is the current primary email address, whereas your mockup doesn't make that very clear

For reference, here's how TripIt solves this same problem:

…and here's how LinkedIn does it:

I don't have many useful tips for physical addresses, sadly (Amazon was my first thought, as in your post).

I do have one reference implementation, this one from a service called comGateway that provides re-shipping products from the US overseas (e.g. for retailers that don't ship overseas):

They call this list your "address book" which I don't really agree with (to me, my address book is full of other people's addresses), and you'll notice they don't offer the ability to select a "primary" address; every shipment requires you to pick explicitly from the set of addresses you've provided.

feedback - Mockup review process

Possible Duplicate:
How can we improve the internal wireframe review?

I am trying to understand what the best practices are for

1. sharing mockups with clients online and


2. capturing feedback on the mockup from them

Ideally, I would prefer to have them comment/provider their input on the mockup screens. Better yet, it would be great if I can collaborative participate in the session.

I request your input on the process you use and works for you.

Is there a name for this line-based halftone style?

I'm wondering what you would call the style/technique of the picture above? It looks similar to linocut, and is halftone but neither of those terms are specific enough.

I'd love some advice on how to apply such an effect to a photo in Illustrator or Photoshop as well (can't google it yet because I'm not sure what it's called)

Answer

It's a style meant to emulate old engravings (look at the portraits on american paper money for an example). Traditionally it was done by an engraver, cutting into the plates.

The example above appears to be done via a PhotoShop filter. There's several on the market that can do that. It's often a form of a halftoning filter.

color - Intuitive colour pickers for non-expert users?

Does anyone have examples of favourite colour pickers (as UI elements, not dedicated color-picking apps or sites) for common, 'everyday' colours - not for RGB or HSL values?

I find traditional colour wheels really unintuitive for common colours - hard for people who don't understand colour theory to know how to pick black, white, or grey:

I quite like Polyvore's:

But what I'd really like to see is one that combines colour and words in some attractive way - Polyvore's squares are so small they work best for people with good eyesight on high-res, bright screens.

I know the concept of 'everyday' colours is problematic, but the UX requirements are:

• let users select colours without understanding how HSL etc work


• let users distinguish between light and dark versions of common colours


• be distinguishable on a mobile, non-retina screen.

stochastic processes - Show that $E[B_t|mathscr{F}_s] = B_s$ for $B_t = W_t^3 - 3 t W_t$

Given prob space $(\Omega, \mathscr{F}, P)$ and a Wiener process $(W_t)_{t \geq 0}$, define filtration $\mathscr{F}_t = \sigma(W_u : u \leq t)$

Let $(B_t)_{t \geq 0}$ where $B_t = W_t^3 - 3tW_t$. Show that $E[B_t|\mathscr{F}_s] = B_s$ whenever $s < t$.

I think this all comes down to manipulation since there are martingales somewhere

My attempt:

Splitting up into $E[W_t^3|\mathscr{F}_s] - 3E[tW_t|\mathscr{F}_s]$ doesn't do anything since those guys aren't martingales? So, I tried splitting it up into:

$E[W_t(W_t^2 - 3t)|\mathscr{F}_s]$

$= E[W_t(W_t^2 - t -2 t)|\mathscr{F}_s]$

$= E[W_t(W_t^2 - t) -2 tW_t)|\mathscr{F}_s]$

$= E[W_t(W_t^2 - t)|\mathscr{F}_s] -2E[ tW_t|\mathscr{F}_s]$

$W_t$ is not $\mathscr{F}_s$-measurable, so we can't take that out...

$tW_{1/t}$ is Brownian and thus a martingale, but I don't know about $tW_t$...

$cW_{t/c^2}$ is Brownian and thus a martingale, but I don't think we can set c = t...

Help please?

Answer

\begin{align*} E\Big(W_t^3-3tW_t \mid \mathcal{F}_s\Big) &= E\Big((W_t-W_s+W_s)^3-3t(W_t-W_s+W_s) \mid \mathcal{F}_s\Big) \\ &=E\Big((W_t-W_s)^3+W_s^3+3(W_t-W_s)^2W_s + 3 (W_t-W_s)W_s^2\\ &\qquad \qquad -3t(W_t-W_s)-3tW_s \mid \mathcal{F}_s\Big) \\ &=E\Big((W_t-W_s)^3\Big) + W_s^3+3W_sE\Big((W_t-W_s)^2\Big)\\ &\qquad \qquad + 3W_s^2 E(W_t-W_s)-3tE(W_t-W_s)-3tW_s\\ &=W_s^3+3W_s (t-s)-3tW_s\\ &=W_s^3 -3sW_s, \end{align*} by noting that \begin{align*} E\Big((W_t-W_s)^3\Big) = E(W_t-W_s) =0, \end{align*} and \begin{align*} E\Big((W_t-W_s)^2\Big) = t-s. \end{align*}

arbitrage - If I am very fast (less than 10 microseconds latency) what would be the first strategy to execute?

Let's assume I found the holy grail of low-latency trading (which I didn't). For educational purposes, what would be the first strategy I would direct my trading code?

Answer

Being very fast within a single datacenter is not as valuable as having the fastest line between two datacenters. So being able to write a very fast program wouldn't be the holy grail of trading anyway (it would be to instantaneously transport information between e.g. NJ and Chicago using quantum entanglement or something.)

That said, if you found an imaginary way to write a program that has zero latency, I would point it toward capturing arbitrage opportunities available within a single datacenter. One example is that on exchanges that list both futures and options on those futures, pure arbitrage opportunities can be available to whoever is fastest to capture them (i.e. violations of put-call parity and variations on that).

options - SPX/VIX Implied Beta Calculation

In https://globalmarkets.bnpparibas.com/r/Volatility_Express_20171128.pdf?t=BG3REXwMP3NZJRN7wY5Vt&stream=true, it states that

3M VIX/SPX implied Beta = (VIX 3M IVOL*VIX 3M futures)/SPX 3M IVOL

How is the RHS derived?