The Fundamentals of Predictive Analytics - Data Science Wednesday - YouTube

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hello and welcome back to data science Wednesday my name is Tessa Jones and I'm
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a data scientist with decisive data and today we're going to talk about
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predictive analytics and what it can do for you
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predictive analytics fits into the spectrum of analytics that we've talked
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about before starting with descriptive which is the most basic of the analytics
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it is basically just cleaning relating summarizing and visualizing your data
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really getting to the questions about what's happening in my business and then
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there's diagnostic which is really getting down to why things are happening
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what's causing my revenue to decline or to increase how are things related
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things like that so if you've got a good base in both of these then we're ready
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to move into predictive analytics which is gonna dive into what's gonna happen
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in the future which is super powerful if you're a business person and you want to
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be able to make good business questions if you have at least an idea of what
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might happen in the future your your answers are already gonna be a little
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bit better so let's dive in so let's go with an example cuz that just makes it
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easier to kind of flow through what's actually happening here so let's pretend
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that we are grocery store owners and if we're already talking about predictive
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analytics you should have a pretty good grasp on descriptive and predictive and
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diagnostic analytics so you probably already have a decent dashboard that
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really tells you what's happening in your business right now so something
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like this where you have you know something here that tells you revenue by
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different departments like foods meats or foods and pastry or how your sales
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changes by product or overtime things like that so you have an idea of what's
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happening in your business but now you really want to know what's going to
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happen in my business so one really common question is how many of a given
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product am I going to sell for every store because this can really give you
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quite answer questions around how you're going to support supply chain processes
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or how you're going to manage the profits that you're going to have things
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like that so the first thing we need to do is talk about what happened
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past we really can't do anything or predict very easily unless we know or at
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least have an idea of what's happened in the past so here we have three lines in
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black that represent basically historical data each line here is one
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year worth of sales for a given product and then the green line here is the
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current year and here's today and if we build a predictive model it's going to
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tell us what's going to happen for the rest of the year so if this is all set
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up and we build a model basically we mix this information with all the data
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that's really clean and well-organized we mash it together with a bunch of
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mathematics and coding and basically we pop out some results and it shows up in
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a visual like this where you have these are the cells that we have had and these
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are the cells that we think we're going to have so a business person can look at
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this chart and say wow we need to put a lot more products to this store because
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I see sales are going to increase or our profit margins are going to be way
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higher than we thought so we can start a new program things like that you can
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really start to get innovative with your business decisions so let's pretend
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we've built this model and it's been running for a year and now we want to
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know how well is this model actually performing so down here we have a chart
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that shows in black what we actually sold and then in green what we thought
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we were going to sell and we see that there's some a couple of pretty big
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misses right here we sold way more than we thought we would which leaves risk to
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you know missing out on inventory or here we predicted we would sell more way
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more than we did so both of these are kind of misses and so we need to go back
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and look at the data and understand what assumptions we we applied that we're
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maybe a little bit wrong or applied incorrectly or look at the data maybe we
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weren't accounting for something and we kind of reorganize that and incorporate
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it into the model and then we redeploy it and then the then we have a better
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model this cycle can you know happen a couple times or it can happen many
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it really depends on the data it really depends on the objective it depends on a
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lot of different things but we do try to minimize the number of times that we're
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having to iterate through this before we can have a really sound predictive model
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so that's predictive analytics in a nutshell basically once you have a solid
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foundation of descriptive and diagnostic analytics we can really start pushing
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forward with predictive analytics and then next week we're going to start
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talking about prescriptive analytics which really gets to the questions of
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okay now that we know what's happening in the future what do we do about it I'm
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Tessa Jones and that's a reindeer