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Hiring: What makes you disqualify someone? by pg_gargleblaster in datascience

[–]__compactsupport__ 2 points3 points  (0 children)

Zeal for models. Modeling is a small part of what we do, and honestly is getting smaller. The majority of work is working with the data to get it into the right format.

I want to learn Data science, where should I start? by shivamsinha212 in datascience

[–]__compactsupport__ 0 points1 point  (0 children)

There is a more advanced book called elements of statistical learning, but it is much more dense. If you find ISLR too easy, try giving that a try.

Download python/R. Get familiar with data wrangling.

Does data scientist uses alot of math in their work everyday? by arjoeee in datascience

[–]__compactsupport__ 1 point2 points  (0 children)

OK interesting question.

I use linear algebra every day, sometimes all day, but I am not sitting there computing eigenvalues or anything. I have to understand the math being used by the libraries I use.

So on one hand, I do math like 95% of the time, but maybe 5% of the time I am actually calculating something. Does that make sense? There are two very different types of utilization of math.

PhD in a different field than undergrad? by califarmb in GradSchool

[–]__compactsupport__ 3 points4 points  (0 children)

Happens a lot. You can use the skills you learned in undergrad to supplement your work.

I want to learn Data science, where should I start? by shivamsinha212 in datascience

[–]__compactsupport__ 2 points3 points  (0 children)

Give Introduction to Statistical Learning with R a read. Let us know what you think of it.

Summer social events by uwo_alt in uwo

[–]__compactsupport__ 4 points5 points  (0 children)

London is a ghost town in the summer (compared to the fall/winter)

What is surprisingly useful to know as a data scientist? by __compactsupport__ in datascience

[–]__compactsupport__[S] 1 point2 points  (0 children)

I have some non-zero charisma in front of people and the ability to know what it is I am talking about without referencing slides.

But hey, play on your phone anyway. I don't care

What is surprisingly useful to know as a data scientist? by __compactsupport__ in datascience

[–]__compactsupport__[S] 5 points6 points  (0 children)

I am AWFUL at power point. I just default to white slides and black text.

Pedigree and Age in Data Science by olddata in datascience

[–]__compactsupport__ -4 points-3 points  (0 children)

Is there a question here, or are you just ranting?

Petition to change our motto to "Fuck PD" by chemenggoose in uwaterloo

[–]__compactsupport__ 47 points48 points  (0 children)

will increase our sex appeal

Well, we've got nowhere to go but up

Is statistics a worthwhile career choice? by [deleted] in statistics

[–]__compactsupport__ 2 points3 points  (0 children)

Not well, lol. Little behind on readings right now.

How do I calculate the correlation between an event and sales uplift? by tallen92 in statistics

[–]__compactsupport__ 0 points1 point  (0 children)

I'd like to say that what I have said only applies to online marketing. As you've noted, in person sales and historical data analysis (I would assume for the purpose of hypothesis generation) are different ball games. Maybe we were talking about different things without knowing it.

How do I calculate the correlation between an event and sales uplift? by tallen92 in statistics

[–]__compactsupport__ -6 points-5 points  (0 children)

Companies, however, do not tend to be okay with losing out on half their projected sales revenue so that they can do a true experiment.

If the business wanted to maximize profit they wouldn't hire someone to analyze the data. They would rely on experience and business knowledge to decide what to do. Observational methods exist for these sorts of problems, but if you have the opportunity to do an RCT to test these small adjustments, why wouldn't you? "Missing out on profits" sounds like "saving money" to me, which doesn't align with paying a salary and benefits to a dedicated analyst.

How do I calculate the correlation between an event and sales uplift? by tallen92 in statistics

[–]__compactsupport__ 0 points1 point  (0 children)

Then OP might as well generate random numbers because a large part of statistics is the design of the experiment, not just the analysis of the data.

How do I calculate the correlation between an event and sales uplift? by tallen92 in statistics

[–]__compactsupport__ 2 points3 points  (0 children)

You usually send some sort of promotional offer via email. If the control group does not receive the offer (or is not eligible to redeem the offer), then the event does not effect them.

Its different if you do a fire sale type event where everyone gets the offer. Then you would probably have to do some sort of time series analysis, as another redditor suggests.

How do I calculate the correlation between an event and sales uplift? by tallen92 in statistics

[–]__compactsupport__ 0 points1 point  (0 children)

perhaps this is different in companies with dedicated data analysis departments.

If OP was told to compute the correlation as a measure of the intervention, I highly highly doubt it. I've worked for these sorts of companies, lauding themselves as "data driven" while using sloppy (if not downright false) methods of analysis. My advice to anyone reading this comment who works for one of these places: get out now. You're better than that and you know it.

How do I calculate the correlation between an event and sales uplift? by tallen92 in statistics

[–]__compactsupport__ 24 points25 points  (0 children)

Don’t compute the correlation. I hate when managers tell you to do bad statistics.

If this were done correctly, you should have selected a target population from your customer base and randomly sampled from that population into test and control. You should have also measured the pre-intervention spend (I.e baseline).

Now, post measurement, you should have also measured the spend between the two groups. Assuming the spend has a nice distribution (almost assuredly it does not) you should perform a regression to test the effect of the intervention. This assumes that any change in mean spend was due to the intervention (which is probably false, but I don’t think they pay you enough to worry about that).

Is statistics a worthwhile career choice? by [deleted] in statistics

[–]__compactsupport__ 6 points7 points  (0 children)

Data Scientist by Day, PhD student by night.