Earlier quoted context omitted.
Seems like you've put some solid work here. Who would you name your top competitors?
Maybe kaggle but different?
this has nothing to do with Kaggle, which is a competition platform
Guesstimate – A Spreadsheet for things that aren't certain
51–60 of 73 posts
Re: Guesstimate – A Spreadsheet for things that aren't certain
#52The mode of the distribution in the video appears to be zero. How is that possible?
I think technically the mode is one of the middle buckets, it looks slightly taller to me.
Anyways, it's a histogram, so the x-axis is split into buckets. The bar all the way on the left is likely some range of hours from 0 to whatever the bucket size is
Re: Guesstimate – A Spreadsheet for things that aren't certain
#53Does this permit Bayesian inference? e.g. looks like graphical probabilistic programming (hooking up various distributions and performing inference), except the key missing component is the ability to observe values for any given distribution beyond the prior.
> the key missing component is the ability to observe values
Spot on, it’d need to load some data on final predictions. Or, it could dump the model in a way that another software could use it.
I was thinking of the same thing.
Re: Guesstimate – A Spreadsheet for things that aren't certain
#54I saw this a couple of years ago, when it was just a project. Now that there's a price, how did you guys decide on a price? How did you find your first customers? For a broadly applicable tool, how did you know where to start looking?
Wouldn’t it be cool if they got it from their own spreadsheet?
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Re: Guesstimate – A Spreadsheet for things that aren't certain
#55Cofounder Here: Happy to see this on hnews again. Update: Matthew (the other cofounder) and I got Guesstimate to a stage we were happy with. After a good amount of work it seemed like several customers were pretty happy with it, but there weren't many obvious ways of making a ton more money on it, and we ran out of many of the most requested/obvious improvements. We're keeping it running, but it's not getting much mo…
Are you able to apply global correlations to all the variates? One of the triggers for the financial crisis in '08 was that the Monte Carlo pricers assumed the various risks were much less correlated than they actually were. For example, they largely assumed that it was unlikely for many mortgages or underlying MBS securities to simultaneously default (low correlation). This is how many AAA rated CDO securities ended…
I would really like to know the answer to the correlations question. It's essential for doing some of the things we do at our company.
Also, are we able to adjust the distribution of each variable?
EDIT: I think you can actually manually create correlations on sheet so it should be fine
Re: Guesstimate – A Spreadsheet for things that aren't certain
#56Cofounder Here: Happy to see this on hnews again. Update: Matthew (the other cofounder) and I got Guesstimate to a stage we were happy with. After a good amount of work it seemed like several customers were pretty happy with it, but there weren't many obvious ways of making a ton more money on it, and we ran out of many of the most requested/obvious improvements. We're keeping it running, but it's not getting much mo…
Are you able to apply global correlations to all the variates? One of the triggers for the financial crisis in '08 was that the Monte Carlo pricers assumed the various risks were much less correlated than they actually were. For example, they largely assumed that it was unlikely for many mortgages or underlying MBS securities to simultaneously default (low correlation). This is how many AAA rated CDO securities ended…
I'd definitely agree that correlations can be a really big deal, especially in very large models like that one.
Guesstimate doesn't currently allow for correlations as you're probably thinking of them. However, if two nodes are both functions of a third base node, then they will both be correlated with each other. You can use this to make somewhat hacky correlations in cases where there isn't a straightforward causal relationship.
Implementing non-causal correlations in an interface like this is definitely a significant challenge. It could introduce essentially another layer to the currently 2-dimensional grid. It's probably the feature I'd most like to add, but the cost was too high so far.
I think Guesstimate is really ideal for smaller models, or for the prototyping of larger models. However, if you are making multi-million dollar decisions with hundreds of variables and correlations, I suggest more heavyweight tools (either enterprise Excel plugins or probabilistic programming).
Re: Guesstimate – A Spreadsheet for things that aren't certain
#57I'm developing a similar open-source app for statistical modeling and inference in the browser: https://statsim.com. You can create probabilistic models and then infer their parameters using algorithms such as MCMC or Hamiltonian Monte Carlo. The app is still in beta but it might be useful. Some models: https://github.com/statsim/models
Re: Guesstimate – A Spreadsheet for things that aren't certain
#58Earlier quoted context omitted.
Are you able to apply global correlations to all the variates? One of the triggers for the financial crisis in '08 was that the Monte Carlo pricers assumed the various risks were much less correlated than they actually were. For example, they largely assumed that it was unlikely for many mortgages or underlying MBS securities to simultaneously default (low correlation). This is how many AAA rated CDO securities ended…
>any multivariate Monte Carlo analysis that doesn't show your sensitivity to correlation is essentially useless This rational is why this tool shouldn't be used for anything consequential -- like business decisions that can sink you company.
In my experience, many consequential business decisions aren't even made with probability distributions, let alone probabilistic models with realistic correlations. I would generally encourage people who are comfortable with more advanced probabilistic systems to use them.
Re: Guesstimate – A Spreadsheet for things that aren't certain
#59Earlier quoted context omitted.
Are you able to apply global correlations to all the variates? One of the triggers for the financial crisis in '08 was that the Monte Carlo pricers assumed the various risks were much less correlated than they actually were. For example, they largely assumed that it was unlikely for many mortgages or underlying MBS securities to simultaneously default (low correlation). This is how many AAA rated CDO securities ended…
I would really like to know the answer to the correlations question. It's essential for doing some of the things we do at our company. Also, are we able to adjust the distribution of each variable? EDIT: I think you can actually manually create correlations on sheet so it should be fine
You can choose from a few distributions (normal, lognormal, uniform) in the main editor, or you can type many others using the function editor. The sidebar describes all of them.
Re: Guesstimate – A Spreadsheet for things that aren't certain
#60Cofounder Here: Happy to see this on hnews again. Update: Matthew (the other cofounder) and I got Guesstimate to a stage we were happy with. After a good amount of work it seemed like several customers were pretty happy with it, but there weren't many obvious ways of making a ton more money on it, and we ran out of many of the most requested/obvious improvements. We're keeping it running, but it's not getting much mo…
Seems like you've put some solid work here. Who would you name your top competitors?
On the question of "what are other ways of doing MC analysis", there are two approaches.
The first is to use Excel apps like Oracle Crystal Ball or @Risk. These are aimed at business analysists. They're pretty expensive, but also quite powerful.
The other option is to use probabilistic programming languages. Stan and PYMC3 are probably the best now, but hopefully, some others will become much better in the next few years.
That said, this is a pretty small space. The main "business competitor" is probably people just using google sheets or Excel without distributions to make models.
Crystall Ball: https://www.oracle.com/applications/crystalball/ @Risk: https://www.palisade.com/risk/default.asp Stan: https://mc-stan.org/ PYMC3: https://docs.pymc.io