I have multiple independent variables that I want to stratify my sampling across, but the result would be way more strata than I can sample. Is there a way to stratify across different character states for each independent variable without creating strata for the interactions of each? Example inside. [more inside]
I've crossed a bunch of plants with one another, and now have a bunch of berries on those plants. Each berry can contain way more seeds than I have room to pot up and grow out individually, so I'm trying to find the point of diminishing returns, where potting up additional seedlings stops giving me new and interesting results, but my math background is inadequate. [more inside]
I want to know where gun owners tend to keep their guns. As I reason, there are only a few places that can be; (1) at home, (2) in their car or (3) on their person. Are there any statistics or studies that show where people keep their primary firearm - one they may say is mostly for protection as opposed to hunting or target practice (even though that firearm may be used interchangeably by some owners)?
I could use some help walking through this: I have Excel data that means more or less depending on where it comes from. When I'm working with it, presenting it, or thinking about it, I want to treat it differently depending on origin. Example within. [more inside]
Any ideas on where I can find a reasonably accurate estimate of the LGBT Youth population in the St. Louis metropolitan area? I've tried several things (listed inside) but keep coming up empty. [more inside]
I am considering leaving a tenure-track faculty position in Psychology in order to have a more normal life. I would be very grateful for suggestions on non-academic careers. More inside. [more inside]
I'm looking for some help cutting through the mix of crap that Google throws up and finding some quality free (or very inexpensive) resources for learning the statistical programming language R. [more inside]
I have a computer science background, but never got much formal training in statistics. I'm working more with data from psychological experiments and am interested in neural networks to model human behavior. I'm looking for two books (or maybe more): an intermediate book on statistics focused on applications in psychology and a basic book in modern neural networks. [more inside]
TA/Instructor looking for an easy way to plug in a list of grades and get statistical information back, preferably in chart form. I would like to see things like the mean, median, and standard deviation, and a visual representation of the the distribution. [more inside]
Please tell me the funniest statistics-related joke or jokes that you know. I give talks and run workshops about statistical concepts - broadly defined - to mixed audiences. Jokes will be used as ice-breakers. The ideal joke will be funny to everybody, and doubly funny to statisticians. [more inside]
We had a NCAA March Madness contest at work, where about 40 of us all filled out brackets on ESPN's site. One of us - the winner of our group - did very well and ended up ranked 6000th out of all 13 million ESPN brackets - top .05%. My question is, was this really statistically unlikely or, given that there were 40 of us, is it unsurprising one of us did that well (e.g., the birthday problem)? What mathematical tools would one use evaluate this question? Thanks!
Over the years as a researcher in the humanities and social sciences I have often made vague comments expressing an intuition, or perhaps a bias, that quantitative analysis and statistical models often made by e.g. economics, quantitative political science and other math-fetishistic disciplines miss or misrepresent truths about human behaviour and society, which are messier and less easy to quantify than these disciplines assume. I would like to be more able to talk about this in detail and with greater specificity of examples than I currently am. More below... [more inside]
Reading this article on the blue got me thinking about conditional probabilities, prediction and causality. I came up with an analytical framing of what I think the article is saying and would be grateful if stats/social science Mefites could tell me if it seems accurate or else set me right. [more inside]
I am looking for good and up to date websites for Chinese economic indicators. GPD, PPI, CES, Import/Export changes, shadow stats, etc. Preferably updated monthly. Does something like the Case Schiller index exists for China?
I've been doing data analysis for about 8 years, and I feel stuck. Where to next? [more inside]
How exactly do you score this Reactions to Research Participation Questionnaire Revised (RRPQ-R) form? I see some hints on the last page, but what steps would a researcher take to turn a stack of completed forms into data the proper way? I could take a guess but I'm curious to know the actual method. Google is seemingly empty of the answer. I do not think I have access to the sources on the last page.
Is there a standard statistics reference that I can buy for easy . . . reference? I'm looking for something that is more encylopedic than a textbook. It doesn't have to be an exhaustive resource, but one that contains most of the standard methods and practices, as well as decent explanations of the statistical theories behind them.
I'm thinking of starting a graduate program that requires rigorous training in statistics. It's been a LONG TIME since I've done any math at all, and even then, I wasn't great at it. Is this too ambitious? [more inside]
Family member (FM), mid-seventies, healthy (some mild arthritis), stubborn. Talked into getting blood work and doctor exam because of family history of kidney problems. Kidneys are great, everything is great, except his blood sugar levels. Doctor says "diabetic," FM very resistant to diagnosis, doctor unable to explain in a way he can understand. I'm the one he talks to most freely, so ... how do I explain this when I don't understand it very well myself? Seeking explanations, and sources if possible. [more inside]
I have the results of a survey, along with a couple of basic descriptive statistics. I'm trying to determine how they were calculated and my one semester of stats isn't holding up. Could you help? Details inside. [more inside]
I have a CSV with one column that contains User IDs. I need to make another CSV that counts how many times each User ID appears in the document, and output it to another CSV That has something like UID1 >> 3; UID4 >> 1; UID20 >> 0. There are thousands of User IDs, so I need to be able to set up a range for it to scan for. Is this possible with free software and not much programming expertise? [more inside]
I need to find out accurate information showing the quantity of university/tertiary/higher education students and lecturers, by age, for Australia and internationally. [more inside]
I have a research project involving about ~90 subjects in two (self-selected) groups. I have collected a number of variables about these subjects (from public sources), and now I would like to do some statistical tests to say whether these variables are significantly correlated with membership in one group or the other. How do I do this? I have a basic knowledge of R and access to Stata 14. [more inside]
I am dubious of a colleague’s assertions about statistics. [more inside]
I have a time series of data - number of "detections" per hour, over time. Each of these points also has two attributes associated with it, x and y. I also have a second time series of data which I expect to correlate with that number of detections per hour, but only with detections within certain combinations of those x and y values. I want to find what range of x and y values has the best correlation. [more inside]
Is there any research, discussions or statistics that link burnt out car bulbs to police stops, and then to either police shootings or anything related violent interactions between arrestees and police?
Galton's quincunx machine was a machine to demonstrate the bell curve. Are there any such machines for non-Gaussian probability distributions? [more inside]
This seems like an easy question but my math skills are underdeveloped, and I do not understand the answers I've found through Google. I would like to know how to appropriately average together standard deviations when all I have is the means, sample sizes, and standard deviations for two or more groups. [more inside]
Choosing a BUGS software package...one with a comprehensible manual or understandable tutorial to allow progress to continue on thesis. [more inside]
There is a statistic that gets thrown at all women trying to get pregnant stating that each month that you only have a 20% chance of getting pregnant assuming each partner is fertile and otherwise healthy. This seems super low (and depressing and discouraging) to me. What gives? [more inside]
Years ago my college roommate took a statistics course. In the textbook was a small, confounding cartoon that appeared to make no sense but was hilarious in its absurdity. I would like to know about that cartoon. [more inside]
I have to validate some input for a database, and I want to present the user with a mathematically accurate estimate of the percentage of data that they entered which may be invalid. The problem is that valid data looks like invalid data 10% of the time. [more inside]
I'm curious about how many Americans have been exposed to meditation and mindfulness, and to what degree. I've had a difficult time finding research about these and related statistics. Can anyone point me in the right direction?
I'm looking for something like the most popular/visited pages for each month (or week, or day) since Wikipedia's debut. I found the Top 25 list which would be perfect if it wasn't for the fact that it starts only in 2013. I'd like to go back as many year as possible. I combed through the statistics department but I can't find anything usable except for a couple of "Top N" pages for a single year. Most pages or sections refer to just little samples and examples. Thanks a lot for any hints Chris
I'm working with some multi-variable data (up to 12 factors per event, from a possible 28 factors) so far I've only seen it discussed as a combination of two factors. Is there a way to elegantly (or at least clearly) display inter-relations of more features? I realize 12 factors is a lot, so anything more than 2 factors would be an improvement. [more inside]
My question is about how to find someone who can appropriately choose a representative set of zip codes from a larger set. How could I get someone to choose, in an intellectually defensible way, a list of 30 to 50 zip codes that essentially represent my entire state? In other words, how could I come up with a list of 30 to 50 zip codes that economically/demographically are a representative subset of the entire state? [more inside]
Our company has decided to measure the jobs we do by assigning points to tasks. The problem here is that departments don’t do the same thing, or the same amount of things. What concerns me is that the company wants to publish a company-wide average, against which members in each department will be compared. [more inside]
Anyone familiar with proc phreg (Cox regression/survival analysis) in SAS who could help me figure out if my code is right? I'm new to survival analysis and my data are set up a little differently than the examples I'm seeing online so I'm not sure I'm doing it right. [more inside]
I am undertaking a fun statistical project, and I need help... [more inside]
I am a TA in an introductory college biology lab. Soon, I have to teach a class of mostly freshmen about t-tests and p-values in conjunction with a field experiment that they are conducting and on which they will have to write a report. I want to make sure I do this right—help me! [more inside]
So I was recently faced with a serious health care decision, and the people advising me strongly disagreed with each other, which made me realize something: I don't know enough science to make well-reasoned decisions for myself and my family. Help me figure out a DIY way to make up the gaps. [more inside]
My state has 709 zip codes. I want to draw reasonably well-grounded conclusions about the entire population of my state (having to do with insurance coverage and ACA subsidies, if you're interested). How many zip codes should I sample? [more inside]
I am looking for a resource that lists probability distributions and their common real-world applications. For example, I'd expect to see: Lognormal - daily returns in the stock market. Poisson - failure rates for mechanical equipment, ... [more inside]
If autism is diagnosed in 1 of 68 children, and there are 381 million people in the country, can I use these two facts to find out how many people in the US are autistic?
I have a statistics and/or probability question and the last time I took a statistics class Vanilla Ice and Andrew "Dice Clay" were multi-millionaires. I am not looking for a problem to be solved, I am asking what statistical technique should I use to determine if a time series of data is due to randomness or not. [more inside]
I recently came up with a statistical thought experiment from watching too many reality game shows, but I'm having trouble remembering how to solve a problem like this. Help me figure out this problem that's been bugging me (and by extension relearn some statistics I've forgotten). [more inside]
How do you calculate the probability of something when it's not as simple as "do it a bunch of times"? Specifics inside. [more inside]
Years ago I came across an introductory book on statistics that introduced the topic by means of a metaphor of a pile of sand (possibly dirt) dropped off in a front yard. As I recall, the author drew the parallel that statistics was the effort to describe the shape and size of the pile of sand. This is all that I can remember of the book (other than my wish that I'd bought it). Does this decription ring any bells?
I have 754 tickets in our development ticket system. All tickets are considered "minor" so they are not very disparate (you would not get one ticket with 4 hours, and another ticket of 4 days). Given that I have ~200 of these items estimate by hand, how can I generate estimates for the rest of the items? [more inside]
What formula do I need to determine the probability that a set of size N contains two elements, each appearing with a specific frequency? [more inside]