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Comment by ozgooen | Hacker News Reader

I wasn't expecting this to go on hnews yet, but happy to take any questions!

Hey, I tried to send you something through Intercom on the site, but something was broken and it wouldn't send. Here's what I tried to write:

Cool idea. Found this from a @worrydream tweet. Some comments after playing with it for a few minutes:

* A bit disappointing that I can only have uniform or Gaussian distributions. At minimum I'd like a binary distribution (coin flip, probably biased coin flip). A lot of things I would want to model need this (e.g., will we close this sale? will we close this investor? that kind of thing.)

* I'm really confused by the arbitrary two-letter codes assigned to things for formulas. Makes the formulas impossible to read. Why not just use the names I give to the cells, or something derived from the names?

Really nice start though! I'm co-founder & CEO of fieldbook.com, another spreadsheet-like tool, so I love information tools and anything that expands the mind's capacity. Best of luck and let me know how I can help!

Sorry to hear about Intercom, will investigate shortly. I heard someone else had a similar issue.

In response to your points:

- Other distribution types are the #1 most requested feature at this time. Binary distributions are possible using functions instead of the built in distributions, though obviously not intuitive. It's built using math.js, which has several random functions of different kinds. (In this case, you could use '=randomInt(0,1)' to produce a coin flip.

http://getguesstimate.com/models/365

- The arbitrary two-letter codes were simply the easiest thing to begin with. I started with something derived from the names, but this presented problems with cells with empty names, especially ones that started empty and later become non-empty. Excel has a pretty sophisticated model for referencing cells. For the sake of getting something shipped, I started with a very simple one. Definitely an area to improve.

- I'd love to talk sometime. I'm also in SF, will send you an email. Thanks for the advice!

Cool, thanks! Yeah, it was not obvious you could create new distribution types with random functions. I didn't look at functions too closely because I didn't expect distributions to be there. Makes sense, though, thanks!

Re the two-letter codes, I totally get doing the simple thing just to launch and get it out there. We face a similar problem in Fieldbook, by the way. Would be happy to explain how our solution works sometime.

I just looked at Fieldbook. The user-interface work you've done is fantastic. I'll save you from shamelessness. Here's a link to the promotional video for anyone who's interested: https://www.youtube.com/watch?v=Qw5f6Qptufc

Give me beta access! I want to play with this thing.

Wow! The developer tools are amazing too: https://www.youtube.com/watch?v=stwlaJGeLoM

Thanks! We were on Show HN not long ago, if you use the link there you can get beta access now: https://news.ycombinator.com/item?id=10752570

Any plans to add different probability distributions? I do this kind of analysis by hand for things like project timelines and cost estimates, but I model each variable with a double triangular distribution (http://www.mhnederlof.nl/doubletriangular.html). You provide a best case, worst case, and then the most likely case. The distribution approximates the long tails on many kinds of distributions.

Definitely. I haven't yet had a request to do a double triangular distribution, that looks really interesting.

It will be a bit of a challenge to make it intuitive, but I'm sure I'll figure out something.

Just so you know, right now there is a second distribution, uniform. You can access it by clicking the 'normal' icon in a normal distribution, where a short list is shown below.

I just made an issue on github, but the uniform distribution looks wonky at the right endpoint.

Much of that is because the react histogram library I used. There are a bunch of issues with it. I definitely intend to replace it with something much better. If any of you recommend tools or libraries for that, I'd be very appreciative.

+1 for more distribution shapes, specifically power law, combinations of power and normal (Which you might want to consider for your soft-attack-long-tail variables over triangular, if the edge between triangles causes you artifacts), and distributions based on empirical collections.

I do the same thing as cpitman, try to figure project times and costs using the same best, worst, most likely. It would be nice to have it automated so when the PHB looks at the numbers they just don't pick the "best case" because we have the "best team". 50 nodes would be plenty, I can roll up tasks into a bigger task set.

I worked on a while for a product to do this. It foundered on the stony shores of my unfamiliarity with angular, which was the sexy new thing at the time.

Have you seen or were you at all inspired by Analytica from Lumina Decision Systems (http://www.lumina.com/why-analytica)? It's been around for about twenty years and is often used in the field of policy analysis when you need you to quantify messy things like human lives in dollars in the face of massive uncertainties.

Also, Oracle Crystal Ball.

This is awesome! Have you heard of Augur? It's a decentalized prediction market: http://augur.net I wonder if the guys there would be interested in this.

Definitely, keeping a close eye. Have long been interested in prediction markets. It would be nice to tie data from them and the Good Judgement project into tools like Guesstimate so people could make forecasts using other strong forecasts.

Pulling data from prediction markets into Guesstimate is an exciting idea. A few thoughts:

* Prediction markets are usually for binary outcomes. I imagine the most useful role of binary variables in Guesstimate would be to mix two different distributions. "If Clinton wins, student debt in 2018 will look like distribution A; if Sanders wins, student debt in 2018 will look like distribution B".

* I'm not sure how Augur (or any other market) reports likelihoods, but it's good to keep in mind that market prices do NOT generally reflect any sort of average belief. See https://www.aeaweb.org/assa/2006/0106_1015_0703.pdf.

That makes sense. It would be very useful to see estimates of how well Presidential candidates would do if they got elected.

In the future, one idea would be to keep track of people's metric estimates in Guesstimate, and later score and rank them on how well they do. So if Charles always reports a 90% confidence interval that's far too optimistic, we could help adjust it automatically next time. This would also allow us to aggregate different opinions directly, essentially being like a mini prediction challenge. This would be a ways off though, and it really depends on what direction the product goes.

The guy who's work was originally the basis for Augur has some interesting things to say about that project (and is working on his own implementation of a Bitcoin-based prediction market): http://www.truthcoin.info/faq/

I love the tool and tweeted about it yesterday. It's brilliant, I love it, excited to try some more complex probabilistic distributions.

Only request would be to allow for private spreadsheets. I can download and run the code locally but this would help many people who are less tech savvy.

Great product - looking forward to seeing how it evolves!

It's nice to see a web app with keyboard support, just please don't highjack the keys if any modifier keys are held down, these are usually for the browser, alt+left to go back as example.

<3 this! Are there any plans for some type of export utility, e.g. some type of JSON serialization of a finished model?

That's definitely on the agenda. Curious, what are you interested in a JSON serialization for?

Oh, it wouldn't have to be that format in particular, I was just guessing how you might represent the worksheet in some useful, repurpose-able manner.

I love the simplicity. Overall, a fantastic product.

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