On Tue, 5 Dec 2000 the anonymous correspondent
"[EMAIL PROTECTED]" wrote:
> Where can I find authoritative data on the undervotes observed in the
> various counties in Florida for the Presidential Election?
>
> My students have suggested that a t-test should be applied determine
> the level
On Sat, 9 Dec 2000 [EMAIL PROTECTED] wrote:
> Since the vote difference between Bush and Gore falls within the margin
> of error for the counting process, ...
Is it, indeed? How do you define "margin of error" for this process?
> ... declaring the winner is mathematically indeterminable ...
On Sun, 17 Dec 2000, xprot wrote:
> What are the odds against rolling a pair of dice 6 separate times, and
> not rolling a 7, 11, or any doubles?
Without thinking about it too hard, I make the probability of this event
about 0.052. (I may be wrong; I muffed it the first time through.)
If you
On Sat, 23 Dec 2000, Jake wrote, inter alia:
> P.S. Canada handcounted thirteen million votes in 2.5 hours. We look
> like idiots.
Yes, well, perhaps we are. There appears not to be much in the
way of counter-evidence, and there may be some debate over what counts
;-) as evidence..
Two comments:
(1) If the coins are numbered (on the non-zero side) 1, 2, 4, 8, ...
then each possible total occurs exactly once. If Derek's coins are
labelled 0 and X (X = 1, 2, 3, ...), these new coins are labelled 0 and
2^(X-1). I don't know if this observation is helpful, since I don't
Jim, a few comments in addition to those made by other respondents:
On Mon, 15 Jan 2001, Jim Kroger wrote in part:
> I'm doing a two-way, 2X2 ANOVA. Suppose I have 20 subjects, and each has
> 25 observations of the following types:
>
> drug1-doseA (25 for each subject)
> drug1-doseB ( " )
> dru
A quibble, and a question (or maybe several, of each), Rich:
On Thu, 25 Jan 2001, Rich Ulrich wrote, inter alia:
> By the way, if you have Pre-Post on one measure, you
> almost need to plot the points on a well-labeled graph
> (what is max, what is min?) before you BEGIN to draw
> conclusions
On Sun, 28 Jan 2001, Veeral Patel wrote in part:
> Out of curiousty i decided to write a small prog to perform the A-D test in
> matlab for the gumbel distribution. Obtaining the gumbel parameters is easy.
> however the difficulty is in the actual A-D computation formula as stated by
> Stephens(1
On Fri, 26 Jan 2001, Rich Ulrich quoted me:
> DB: > What most people who use "ordinal" and "disordinal" seem to mean
> > is a plot of the cell means (or of regression lines), with no
> > adjustment for main effects: so, a display that includes the
> > interaction AND the main effects. I take
On Mon, 29 Jan 2001, Chris wrote in part:
> My current job requires me to analyze margins from the sales of various
> products and provide an average for each during the quarter. I am using a
> very large sample of all product sales by month. (Margin, i.e. not markup.
> For those not familiar, ma
On Tue, 30 Jan 2001, Kathleen Bloom wrote:
> If you have unequal n's, and want to determine linear parameters, you can
> develop new coefficients by taking the normal unweighted coefficients
> (e.g., -1, 0, +1, for three group design) and the formula:
> n1(X1) + n2(X2) + n3(X3)/ n1+n2+n3 w
A quick reply. Looks somewhat like the second course ("Intermediate
Statistics and Research Design") I taught for some years at OISE,
Toronto, which was (and is) the Graduate Department of Education for
the University of Toronto. Ask for more later if you want...
On Tue, 20 Feb 2001, Lise De
Perhaps jthis is too superficial -- no time to think more deeply just
now. But I suspect the difference between your two scenarios below is
that with exactly 5 computers to deal with (i.e., population size = 5)
you are sampling without replacement (which is only sensible, for the
background s
On Wed, 28 Feb 2001, Mike Granaas wrote in part (and 2 paragraphs of
descriptive prose quoted at the end):
> ... is there some method that will allow him to get the prediction
> equation he wants?
Probably the best approach is the multilevel (aka hierarchical) modelling
advocated by previous
On Thu, 22 Mar 2001, Paul R Swank wrote:
> I prefer the ocular test myself.
Were you referring to the intraocular traumatic test?
(It strikes you between the eyes.)
-- Don.
Donald
On Sat, 28 Apr 2001 [EMAIL PROTECTED] wrote:
> I just joined the listserv. Our professor is giving us extra credit if
> we join an email list re: stats. I was able to pull up one of his
> messages from last year. Pretty cool. Have a great day!
You might ask him whether additional extra cre
On Fri, 4 May 2001, Alan McLean wrote:
> Can anyone tell me what is the distribution of the ratio of sample
> variances when the ratio of population variances is not 1, but some
> specified other number?
Depends. If the two samples on which the variances are based are
_independent_, s^2(1)/s^2
In response to Doug Sawyer's post:
> >I am trying to locate a journal article or textbook that addresses
> >whether or not exam quesitons can be normalized, when the questions
> >are grouped differently. For example, could a question bank be
> >developed where any subset of questions could be
On Fri, 22 Jun 2001, Marc Esser wrote:
> After a closer look at the trials which I want to summarize, I noticed
> that not the means are reported, but the medians.
> Do you have an idea how to calculate an effect size with this
> information, e.g. median change of hospitalization time.
> The p-
On Sat, 7 Jul 2001, David Schaefer wrote:
> My Stats professor is having us run some correlations and what not
> through SPSS. She has asked us to transform some raw scores to
> z-scores for a reading achievement test. The commands she has asked
> us to type in the syntax editor is:
>
On Tue, 10 Jul 2001, Alex Yu wrote:
> I am trying to understand Triangular coordinates -- a kind of graph
> which combines four dimensions into 2D
You meant, "condenses four dimensions into 3D", didn't you? Your
subsequent description indicates three dimensions all together, two
of them use
On 13 Jul 2001, Jonty Tuffin wrote:
> Hi, I'm trying to represent the data of a simple bar graph as a single,
> curved line. How do I do this?
See Chapter 5 of Draper & Smith, Applied Regression Analysis (2nd ed.),
and references therein. They deal explicitly only with representing a
functio
On Sun, 15 Jul 2001, Melady Preece wrote:
> I have done a paired t-test on a measure of self-esteem before and
> after a six-week group intervention.
>
> There is a significant difference (in the right direction!) between
> the means using a paired t-test, p=.009. The effect size is .29 if I
On Tue, 17 Jul 2001, Cantor wrote:
> Does anybody know where I can find program on the website which [can]
> compare two texts/articles and settle whether or not they are similar
> assuming any significant level.
Sorry, Cantor: this is not possible, in general.
One can discover whether two
Hi, Ivan.
I think your problem may not be so simple as you've described it.
But to begin with the simplest: In terms of area in mm^2, simply
multiplying length x width, all of the ultrasound (US) samples except one
have smaller areas than any of the high-speed drill (AR) samples; 6 of
Hi, Dennis!
Yes, as you point out, most elementary textbooks treat only SRS
types of samples. But while (as you also point out) some more realistic
sampling methods entail larger sampling variance than SRS, some of them
have _smaller_ variance -- notably, stratified designs when the st
The answers to your questions depend heavily on structural information
that you almost certainly don't have, else one would not bother to have
arranged a voting process. But consider two very different cases:
A. Voters are absolutely indifferent to candidates: that is, all the
candidates a
On Wed, 25 Jul 2001, Dennis Roberts wrote (edited):
> For a class I used an example from moore and mccabe, a 2 factor anova
> with 4 levels of factor A, 4 levels of factor B, a completely
> randomized design, n=10 in each of the 16 cells.
> Now, after the data are [conveniently arrayed], it i
Use the table twice -- for P(0 I did not try to examine your work thoroughly but at the very beginning
> I try to count P(z1 changed. What about z2?
in response to "EAKIN MARK E" <[EMAIL PROTECTED]>, who had written:
> > I have just finished creating an ASP web page that will help students
>
If you don't happen to have a convenient r <--> Z conversion table
handy, it may be helpful to know, for step 1. below, that
Z = 0.5 log((1+r)/(1-r)) or, equivalently,
Z = tanh^(-1)r = the hyperbolic arctangent of r.
("log" is the natural logarithm.)
It follows that, given a
On Fri, 27 Jul 2001, Nadine Wells wrote in part:
> Does anyone know what the power link function does in SAS? [...] when
> I plot the equation based on the parameter estimates, the model doesn't
> seem to look like I want it to. [...] I am trying to get SAS to run a
> model that resembles e
Some clarification would help. See below.
On Wed, 1 Aug 2001, Teen Assessment Project wrote:
> I have an overall sample of 5000+ from 40+ different towns and 6
> different grades.
In approximately equal numbers per town/grade, or not?
Are all 6 grades (which grades?) represented in each t
On 31 Jul 2001, ToM wrote:
> what is the opposite of a log?[logarithm]
An antilog [properly, antilogarithm]. Equivalently, 10 to that power
(if, as in your example, you are taking logarithms to the base 10); or
e to that power (if you are taking natural logarithms), which is also
called
On Mon, 6 Aug 2001, Philip Ackerman wrote:
>I am looking through a introductory statistics book, and I have a
> question regarding the binomial distribution. Is this distribution a
> sampling distribution?
The short answer is "Yes". That is, the binomial distribution
b(k;n,p) des
On 14 Aug 2001, Nolan Madson wrote:
> I have a data set of answers to questions on employee performance.
> The answers available are:
>
> Exceeded Expectations
> Met Expectations
> Did Not Meet Expectations
>
> The answers can be assigned weights [that is, scores -- DFB]
> of 3,2,1 (Exceeded,
On Wed, 15 Aug 2001, Silvert, Henry wrote:
> I would like to add that with this kind of data
[three ordered categories per item, scored {3,2,1}]
> we use the median instead of the average.
I cannot resist pointing out two things:
(1) At the level of individual items, the median of th
On 16 Aug 2001, John Uebersax asked for software "that produces
publication quality Venn diagrams":
> I want something to summarize and communicate to non-statisticians
> (e.g., physicians) the overlap between two sets (such as patients who
> have Major Depression those who receive antidepressa
One approach: (I assume that by "residual" you mean (O-E)/sqrt(E) for
each cell of a two-way frequency table, where O=observed frequency and
E=expected frequency under the null hypothesis). For the several (or
the single) largest residual(s), report O and E as proportions (of total
N). Expr
On Wed, 15 Aug 2001, Melady Preece wrote in part [edited]:
> ... about a project I am about [to] begin. The goal is to use a
> variety of individual predictors (IQ, previous work experience,
> education, personality) to develop a model to predict "success" after
> a vocational rehabilitation
On 21 Aug 2001, RFerreira wrote [edited]:
> The formula [for] the Standard Deviation, SD=((x-mean)^2/(n-1))^0.5,
> can be applied to any data set. [With] that value we know two things
> about the set: mean and SD. With these two values we can have one
> powerful intuitive use to them: The
On 21 Aug 2001, Atul wrote:
> How do we calculate the adjusted r-square when the error degrees of
> freedom are zero ? (Or in other words, number of samples is equal to
> the number of regression terms including the constant.)
> Such a situation leads to a zero in the denominator in the expres
On Sun, 26 Aug 2001 [EMAIL PROTECTED] wrote:
> I have trouble to solve this probability problem. Hope get help here.
>
> There is N balls, Pick up M1 balls with replacement from them.
> what is the expected value of different balls we pick up?
"Expected value" of what characteristic of the ba
On Tue, 28 Aug 2001, Dennis Roberts wrote in part:
> however ... the "flagging" of "outliers" is totally arbitrary ... i
> see no rationale for saying that if a data point is 1.5 IQRs away from
> some point ... that there is something significant about that
If the data are normally distributed
On Sat, 8 Sep 2001, Magenta wrote in part:
(responding to Rich Ulrich's remark:)
> > Michelle, I hope that you now know that you got tangled up in
> > hypothetical illustrations which you now regret.
>
> Sure do, I think that if you redid it so that the scale was now:
>
> don't agree
On Thu, 13 Sep 2001, Paul R. Swank wrote in part:
> Dennis said
>
> other than being able to say that the experimental group ... ON AVERAGE ...
> had a mean that was about 1.11 times (control group sd units) larger than
> the control group mean, which is purely DESCRIPTIVE ... what can you say
Hi, Carol. I'm taking the liberty of posting this to the Edstat
(statistical education) list as well as the Minitab list.
On Fri, 21 Sep 2001, Carol DiGiorgio wrote:
> My question is: I would like to run 2-way ANOVA on my data.
> Unfortunately it doesn't meet the assumptions of normality or
On Sun, 30 Sep 2001, John Jackson wrote:
> Here is my solution using figures which are self-explanatory:
>
> Sample Size Determination
>
> pi = 50% central area 0.99
> confid level= 99% 2 tail area 0.5
> sa
Turns out the method I originally suggested is unnecessarily cumbersome.
A more elegant method is described below.
On Sat, 29 Sep 2001, Donald Burrill wrote in part:
> COPY c1-c35 to c41-c75; # Always retain the original data
> OMIT c1 = '*';
On Wed, 24 Oct 2001, Rich Ulrich wrote in part:
> It has been my impression (from google) that CA is more popular
> in European journals than in the US, so there might be better
> sites out there in a language I don't read.
("CA" = correspondence analysis,
ou en francais analyse des correspo
In reviewing some not-yet-deleted email, I came across this one, and have
no record of its error(s) having been corrected.
On Sat, 29 Sep 2001, John Jackson wrote:
> How do describe the data that does not reside in the area
> described by the confidence interval?
>
> For example, you have a tw
On Sun, 28 Oct 2001, Melady Preece wrote:
> Hi. I want to compare the percentage of correct identifications (taste
> test) to the percentage that would be correct by chance 50%? (only two
> items being tasted). Can I use a t-test to compare the percentages?
> What would I use for the s.d. f
On Wed, 31 Oct 2001, Glen Barnett wrote, in response to my comment:
> > On Sun, 28 Oct 2001, Melady Preece wrote:
> >
MP> Hi. I want to compare the percentage of correct identifications (taste
MP> test) to the percentage that would be correct by chance 50%? (only two
MP> items being tasted). C
On Thu, 1 Nov 2001, Chia C Chong wrote:
> I am a beginner in the statistical analysis and hypothesis. I have 2
> variables (A and B) from an experiment that was observed for a certain
> period time. I need to form a statistical model that will model these
> two variables.
Seems to me you're
On 3 Nov 2001, Gilbert wrote:
> If I have a density function defined as:
>
> f(x)=(1/4)x 0<=x<=2
> f(x)=-(1/4)x + 1 2 f(x)=0 elsewhere
>
> (so the density function is a triangle of height (1/2))
>
> how do I find the distribution
You persist in repeating your original request in your original phrasing,
with no elaboration(s) that might resolve the ambiguities therein.
On Sat, 10 Nov 2001, Mark T wrote:
> On Fri, 09 Nov 2001 Rich Ulrich <[EMAIL PROTECTED]> wrote:
>
> > On Thu, 8 Nov 2001 Mark T <[EMAIL PROTECTED]> wro
On 12 Nov 2001, Niko Tiliopoulos wrote:
> I am acting as the stats advisor for my unit in the psychology
> department of the University of Edinburgh, UK. Last week a colleague
> of mine presented me with the following issue, and I am not quite sure
> how to respond:
>
> She is running a psych
On Tue, 13 Nov 2001, Wendy (alias Eric Duton?) wrote:
> When applying multiple regression on timeseries data, should I check
> (similarly to ARIMA-models) for unit roots in the dependent variable
> and the predictor variables and perform the necessary differencing
>
> OR
>
> could I simply st
On Wed, 14 Nov 2001, Alan McLean wrote in part:
> Herman Rubin wrote:
> >
> > A good exam would be one which someone who has merely
> > memorized the book would fail, and one who understands
> > the concepts but has forgotten all the formulas would
> > do extremely well on.
>
> Since to underst
> > On Tue, 13 Nov 2001, Wendy (alias Eric Duton?) wrote:
> >
> > > When applying multiple regression on timeseries data, should I check
> > > (similarly to ARIMA-models) for unit roots in the dependent variable
>
> > > and the predictor variables and perform the necessary differencing
> > >
>
On 17 Nov 2001, Myles Gartland wrote:
> In an F distribution, the critical value for the lower tail is the
> reciprocal of the the critical value of the upper tail (with the
> degrees of freedom switched).
>
> Why? I understand how to calculate it, but do not get why the math
> works.
Essentia
On 20 Nov 2001, J. Peter Leeds wrote:
> I'm working on a formula for measuring decision making skill and am
> trying to estimate the probability that a person of known skill can
> distinguish among different response option contrasts and avoid a type
> II error.
One effective
I second Dennis' question. While indeed "MINITAB recognizes the missing
values", what it does with them depends on the procedure being used:
e.g., for CORRelation it uses all cases for which each pair of variables
is complete ("pairwise deletion of missing data"), and therefore, for a
data set l
On Fri, 28 Sep 2001, John Jackson wrote in part:
> My formula is a rearrangement of the confidence interval formula shown
> below for ascertaining the maximum error.
E = Z(a/2) x SD/SQRT N
> The issue is you want to solve for N, but you have no standard
> deviation value.
On Sat, 24 Nov 2001, L.C. wrote:
> Thanks for the reply!
>
> As for the iid, it's reasonable to believe the questions could be
> drawn from some population. Why not the answers?
If the questions are selected in accordance with some table of
specifications, they are not from _a_ population,
On Tue, 27 Nov 2001, Thom Baguley wrote in part:
> Donald Burrill wrote:
> >
> > On Fri, 23 Nov 2001, L.C. wrote:
> >
> > > The question got me thinking about this problem as a
> > > multiple comparison problem. Exam scores are typically
> > >
> William B. Ware <[EMAIL PROTECTED]> wrote:
> >Anyway, more to the point... the "add one" is an old argument based on
> >the notion of "real limits." Suppose the range of scores is 50 to
> >89. It was argued that 50 really goes down to 49.5 and 89 really
> >goes up to 89.5. Thus the range
"The story is about six students who ... The instructor ... tells them
to report the next day for an exam with only one question. If they all
get it right they all pass. They were seated at corners of the room and
could not communicate."
Must have been an interesting room, with six corners
On Fri, 12 Oct 2001, Desmond Cheung (of Simon Fraser University,
Vancouver, BC) wrote:
> Is there any mathematical analysis to find how much the two peaks stand
> out from the other data?
Hard to answer, not knowing where you're coming from with the question.
Any answer depends on the model
On 1 Dec 2001, jenny wrote:
> What should I do with the missing values in my data. I need to
> perform a t test of two samples to test the mean difference between
> them.
> How should I handle them in S-Plus or SAS?
1. What do S-Plus and/or SAS do with missing values by default?
(All
On Sun, 9 Dec 2001, Ronny Richardson wrote in part:
> Bluman has a figure (2, page 333) that is supposed to show the student
> "When to Use the z or t Distribution." I have seen a similar figure in
> several different textbooks.
So have I, sometimes as a diagram or flow chart, sometimes in par
On Fri, 14 Dec 2001, Wuensch, Karl L wrote:
> I came across a table of costume jewelry at a department store with a
> sign that said "150% off. " I asked them how much they would pay me to
> take it all off of their hands. I had to explain to them what 150%
> meant, and they then explained t
On Thu, 20 Dec 2001, Johannes Hartig wrote:
> Does anyone know the original applications
> or the "meaning" of the "S"-function in SPSS?
> I know the function itself:
> Y = e**(b0 + (b1/t)) or
> ln(Y) = b0 + (b1/t)
> and I know how the curve looks like, but I am wondering in which
> fields of re
On Sat, 22 Dec 2001, Ralph Noble asked:
> How would you have done this?
>
> A local newspaper asked its readers to rank the year's Top 10 news stories
> by completing a ballot form. There were 10 choices on all but one ballot
> (i.e. local news, sports news, business news, etc.), and you had to
On 24 Dec 2001, Carol Burris wrote:
> I am a doctoral student who wants to use student performance on a
> criterion test, a state Regents exam, as a dependent variable in a
> quasi-experimental study. The effects of previous achievement can be
> controlled for using a standardized test, the Io
On Tue, 11 Dec 2001, Vadim and Oxana Marmer wrote:
> besides, who needs those tables? we have computers now, don't we?
> I was told that there were tables for logarithms once. I have not seen
> one in my life. Is not it the same kind of stuff?
If you _want_ to see one, you have no farther to go
On Fri, 28 Dec 2001, Petrus Nel wrote:
> I require some advice regarding the following: One set of variables is
> the grades obtained by students for different high school subjects
> (i.e. the symbols candidates obtained such as A, B, C, D, etc. for each
> subject). The other set of variables
On Wed, 26 Dec 2001 [EMAIL PROTECTED] wrote (edited):
> > > I came across a table of costume jewelry at a department store with
> > > a sign that said "150% off. " I asked them how much they would
> > > pay me to take it all off of their hands. I had to explain to them
> > > what 150% meant,
[Stan: Please observe that this is copied to edstat. -- Don.]
On Sat, 29 Dec 2001, Stan Brown wrote:
> I think I've got some sort of mental block on the following point.
> Can someone explain this to me, plainly and simply, please?
>
> Let me start with a sample problem, NOT created by me:
On Sun, 30 Dec 2001, Stan Brown wrote in part:
> A. G. McDowell <[EMAIL PROTECTED]> wrote:
> >The significance value associated with the one-tailed test will always
> >be half the significance value associated with the two-tailed test,
>
> For means, yes. Not for proportions, I think.
Oh? W
In trying to clear out my e-mail inbox, I came across this post, for
which there seemed not to have been any responses.
On Fri, 2 Feb 2001, Caroline Brown wrote:
> I have an analysis problem, which I am researching solutions to, and
> David Howell of UVM suggested I mail the query to you.
>
101 - 180 of 180 matches
Mail list logo
