1. Announcement:
05-10-2017
Views:
1,895
Page 39 of 54 First ... 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 Last
Threads 2281 to 2340 of 3193

# Forum: Statistical Research

Statistical theory and methodology. Mathematical statistics. Parametric inference. Nonparametric inference.

1. ### Sticky: Proof of the day

In this thread we post one (or more if you can't wait) proof a day. I'll start by proving the that V=\sigma^2(X'X)^{-1} in the linear...

• Replies: 14
• Views: 18,751
10-11-2014, 12:02 PM
1. ### What is study population in Statistics?

this is a question that i have to answer * you have been requested to design a study to determine the prevelence of hypertention in my area. 1....

• Replies: 1
• Views: 9,845
09-20-2011, 08:50 AM
2. ### fixed or random factor for ANOVA

I've had a discussion with a colleague over the proper way to analyse results of an experiment. We tested the performance of 6 subjects in a...

• Replies: 1
• Views: 3,085
09-19-2011, 08:12 PM
3. ### Comparing two distributions using random drawing.

Hi all, So this is going to be a bit of a silly question: but one i've been pondering for ages. So say i've used a t-test and found two groups...

• Replies: 7
• Views: 3,935
09-18-2011, 08:11 AM
4. ### Sample, population on Facebook

Hello everyone, i need help verifying if my method is correct or if you can find any problems with it, and if you can i would like you to propose...

• Replies: 9
• Views: 2,956
09-16-2011, 05:36 AM
5. ### Best test to use?

Hi Everyone, I am trying to design a medical study and having difficult for teh best to use, in summary: Stage 1: Patients are classified into...

• Replies: 0
• Views: 1,637
09-15-2011, 06:02 PM
6. ### How to calculate credibility interval limits

Hi everyone. My name is Choi. I'm working on detecting drug adverse reaction signals using health insurance data. I have a problem in getting...

• Replies: 2
• Views: 5,424
09-14-2011, 09:32 PM
7. ### paired or unpaired T-Test or even some other test?

Hello there, I am trying to help out some students of medicine who are writing at their phd-thesis in germany. they have data from several...

• Replies: 7
• Views: 3,640
09-14-2011, 07:18 PM
8. ### Bayesian Variable Transformation (solve for PDF)

Hi I'm struggling with where to start for this variable transformation problem. X~Bin(N,p) so that p(X=x) = (N choose x) * (p^x) * (1-p)^(N-x) ...

• Replies: 2
• Views: 2,192
09-14-2011, 06:11 PM
9. ### multiple levels of indepenent variable

I have three x variables (a,b,c) and b is nested in a and c is nested in b. As you can imagine, there are over 100 levels of c and about 25 levels...

• Replies: 2
• Views: 2,112
09-14-2011, 02:56 PM
10. ### Choosing a test value for a one sample t-test

Hi all, I am trying to determine how best to test a hypothesis I have formulated. I am examining a new user interface that allows the user to...

• Replies: 11
• Views: 4,089
09-13-2011, 01:28 PM

So I'm trying to make my data match, in some ways, those used by the CDC (NCHS, specifically). In particular, I need to calculate age-adjusted...

• Replies: 0
• Views: 2,002
09-13-2011, 12:28 PM
12. ### Variance, means and clusters

I have a question for you, hopefully it's not too trivial, but I a'm not an expert :) I have the distribution, within a certain population, of a...

• Replies: 0
• Views: 1,831
09-13-2011, 10:44 AM
13. ### regression time series

Dear Members, I need to do time series analysis. I have retail sales data of a retail company since January 2006(every month). I need to forecast...

• Replies: 2
• Views: 2,181
09-12-2011, 10:00 PM
14. ### Within-Subjects for categorical data

Hello, I am struggling to find a suitable statistic test for one of my studies: I have 4 different conditions, and I want to test if my results...

• Replies: 0
• Views: 1,711
09-12-2011, 04:09 AM
15. ### Standard Errors of Exponential Smoothing Coefficients

Hello, I use SAS ETS to estimate a single exponential smoohting model. When i select the optimize option for the estimation of the smoothing...

• Replies: 0
• Views: 2,072
09-12-2011, 03:25 AM
16. ### non-parametric version of a two-factor repeated measure ANOVA

Hi everyone, I had planned to perform a two-factor repeated measure ANOVA on the data that I have, but the data that I am using is not normally...

• Replies: 4
• Views: 5,105
09-11-2011, 11:07 AM
17. ### Text book or article exposition on MLE (non-linear least squares) error analysis

I am looking for a rigorous mathematical development of non-linear least squares error analysis, specially the accuracy of the MLE estimate -- either...

• Replies: 0
• Views: 1,510
09-10-2011, 01:02 PM
18. ### Question about phi range in AR(1) process

Hello, Makridakis Forecasting text book says that phi should be restricted to -1<phi<1. I thought that this restriction should exist only if we...

• Replies: 4
• Views: 5,198
09-08-2011, 02:08 PM
19. ### Question about theta range in MA(1) processes

Hello, According to forecasting textbooks (e.g. Diebold, Makridakis etc) the theta coefficient in an MA(1) model should be between -1 and 1...

• Replies: 1
• Views: 4,035
BGM
09-08-2011, 08:45 AM
20. ### Shapiro-Wilk normality test: what is the null distribution

Hi everyone The Title says it all. I'd like to know what is the null distribution of the Shapiro-Wilk test statistic. I'm also curious to see it's...

• Replies: 4
• Views: 5,173
09-08-2011, 04:16 AM
21. ### single Likert scale question analysis

I work for a holiday company which uses a 7 grade Likert scale questionnaire to collect feedback from our guests. This is my first foray into...

• Replies: 2
• Views: 3,761
09-08-2011, 03:57 AM
22. ### different intercept with Multinomial vs Binomial Logistic?

I have run the same set of Xi on the same data, using both Multinomial and Binomial logistic regression via SPSS. (The outcome in both cases was...

• Replies: 0
• Views: 2,691
09-06-2011, 03:02 PM
23. ### Using "AIC per sample" to compare logistic regression models

I'm generating nested models using logistic regression and comparing them by AIC. One issue that arises is that not all samples have all...

• Replies: 1
• Views: 2,434
09-05-2011, 10:34 PM
24. ### test which of two models is better predictor -- but the two are correlated with each

Dear All -- Can anyone please please help me? I have a dichotomous dependent variable Y There are two alternative models for predicting Y The...

• Replies: 6
• Views: 3,490
09-02-2011, 06:46 PM
25. ### Using mean measures in ANOVA

Hi everyone, I'm a bit confused. I have conducted a within-subjects experiment to evaluate a new user interface. I have two independent variables:...

• Replies: 0
• Views: 1,553
09-01-2011, 03:52 PM
26. ### Fisher's exact test

I have always learned that if you have a contingency table that violates the chi square assumption of more than 20% of cells having expected count...

• Replies: 3
• Views: 8,908
09-01-2011, 02:02 PM
27. ### Normality Assumption

Say there is 100 observations, but these observations are equally broken into 2 genders and 5 cities. When creating a qq plot or just checking...

• Replies: 3
• Views: 2,439
09-01-2011, 01:39 PM
28. ### Ideas with paired data

Yesterday I was lucky enough to work with a statistician from another section in my division. He took me along on one of the consultations he...

• Replies: 5
• Views: 3,913
08-31-2011, 04:45 PM
29. ### Tails and QQ Plot

Does Anybody know if exists a formal proof about the well known properties of the qq plot? "families of symmetrical distributions with tails heavier...

• Replies: 0
• Views: 4,724
08-31-2011, 08:42 AM
30. ### non parametric hierarchical regression?

Hello, I have non parametric data and need to condcut a regression with covariates as well. I have tried to transform the data but still they are...

• Replies: 4
• Views: 5,563
08-30-2011, 03:43 PM
31. ### Request for help on deciding how to analyse some data

I have a group of students who have data for % Attendance before and % Attendance after These students can be split by various factors, depending...

• Replies: 2
• Views: 2,163
08-30-2011, 03:02 AM

Hello! This is probably rather basic, but I'd appreciate any input. The sample: I have survey responses from a sample of about 4000 German...

• Replies: 2
• Views: 2,321
08-30-2011, 03:00 AM
33. ### Repeated measure ANOVA shows a significant difference but not post-hoc analysis

Hi, I am kind of new to statistics and I did a comparison that I can't really digest its results. My participants rated the usefulness of 7...

• Replies: 2
• Views: 7,558
08-29-2011, 04:08 PM
34. ### DF and fishers vs. pearson's

Hallo everyone I'm having a mental block today, and having trouble getting my df value. So, here's a summary of my data to help: 32...

• Replies: 3
• Views: 2,606
08-29-2011, 12:04 PM
35. ### Best design for this experiment?

Hello all. I am having some trouble with my experiment and would be the best way to analyze the data. I have 4 different chemicals each at one...

• Replies: 16
• Views: 4,909
08-26-2011, 04:55 PM
36. ### Coding Data

I am examining the relationship between employee level of education and the severity of their disciplinary offenses. I coded education...

• Replies: 21
• Views: 5,737
08-26-2011, 09:30 AM
37. ### Power

Hi there, I need some help getting my head around this power concept. If there's a small but important effect, should you try and find it...

• Replies: 9
• Views: 2,424
08-25-2011, 08:35 PM
38. ### On what statistical significance test should I use

Hi everyone, First and foremost, my skills in statistics are quite basic so what I am about to ask may sound very stupid. That being said, here...

• Replies: 7
• Views: 2,263
08-24-2011, 01:33 PM

Hello I am conducting research into how behvaviour changes from year 1 to year 2 of study on a college course. I have provided students with a...

• Replies: 9
• Views: 5,104
08-23-2011, 07:58 PM
40. ### How do I report marginal means of a two-way unrelated ANOVA correctly? APA-style

Hello, after doing a two-way unrelated ANOVA (General Linear Model > Univariate) on SPSS, I am confused how to report the output correctly. My...

• Replies: 0
• Views: 6,531
08-21-2011, 05:46 PM
41. ### Accelerated Bootstrap - mediation

Howdy! :tup: Can anyone explain accelerated bootstrap to me? I've got it reported in a research report and I can't really figure it out. ...

• Replies: 2
• Views: 5,029
08-20-2011, 04:15 PM
42. ### Package testing using likert scale

We recently finished a survey using a likert scale to compare attributes of consumer packaging(sample question below). The same question was asked...

• Replies: 0
• Views: 2,488
08-19-2011, 04:44 PM
43. ### How to estimate two series covariance with unlined observed data?

Sorry if I use the wrong terminology. My problem is, suppose I have two time series, they change every day. However, I can only observe them...

• Replies: 1
• Views: 1,911
08-17-2011, 10:22 PM
44. ### Tool to suggest on sample selection

I have data which can be represented in a cube (3 dimension) and altogether number of instances(population) are very high. I want to select a fair...

• Replies: 1
• Views: 1,812
08-17-2011, 10:32 AM
45. ### Help!SEM fitting index all failed,tho reliability and validity test passed.Reason?!

Dear all brilliant members, I am a new analyzing thesis data. Im conducting a survey about people's behavior intention, but i came into a serious...

• Replies: 0
• Views: 1,609
08-17-2011, 07:17 AM
46. ### Was thinking Kendall's Tau but...(correlation)

Hey guys, I was wondering if you could help me out with this: I have seven sites along the west coast each with two types of data and several...

• Replies: 16
• Views: 6,148
08-15-2011, 08:06 PM
47. ### repeated measure

:shakehead Hey there, I'm a bit confused about what is meant with repeated measure, it is applicable only in a case when a drug or treatment is...

• Replies: 1
• Views: 1,570
08-15-2011, 12:27 PM
48. ### Bic

I am a graduate student who wants to learn more about the Bayesian information criterion (BIC) for a project I am working on. What do you think is...

• Replies: 0
• Views: 1,602
08-11-2011, 09:51 PM
49. ### R^2 in Shrinkage Estimators

I am just learning about Shrinkage Estimators. I was wondering how R^2 would be defined for this. I have googled a bit but did not really get...

• Replies: 1
• Views: 2,135
08-11-2011, 03:35 PM
50. ### Minimum Sample Size for a Survey

Hi guys, Here's a question I've been struggling with over the past week. My employer would like to perform a survey to gauge public opinion on a...

• Replies: 3
• Views: 2,685
08-11-2011, 02:21 PM
51. ### How do I determine the Correlation Coefficient from a best fitting equation.

I'm confused about how to determine the correlation coefficient after you find a linear regression line formula. I'm porting some linear...

• Replies: 0
• Views: 1,838
08-11-2011, 11:32 AM
52. ### panel data

Hey guys, I'm analyzing cash flows from companies. I have panel data lined up that includes 4 companies with 2 years worth of cash flows. Data is...

• Replies: 1
• Views: 1,750
08-10-2011, 04:52 PM
53. ### What test can I use to compare categorical and continuous variables?

Hello guys: I have two sets of data, actual outcome (live vs. dead), which is categorical, and a risk adjustment predicted outcome, which is...

• Replies: 14
• Views: 13,048
08-09-2011, 02:58 PM
54. ### Correlation Over Time

Hello, I have data regarding the number of blood cells, and the number of a certain protein associated with blood cells, from 15 blood samples at...

• Replies: 1
• Views: 3,270
08-09-2011, 01:57 PM
55. ### Equivalent to RMSE for logistic regression?

I understand that RMSE is a useful summary measure for assessing predictive power of regression model with continuous dependent Y. Is RMSE equally...

• Replies: 1
• Views: 6,481
08-09-2011, 10:54 AM
56. ### cross-validation of prognostic model (test-set method)

I am cross-validating a logistic regression model using the test-set approach, with 70% training data in the test set and 30% in the validation "set"...

• Replies: 0
• Views: 2,390
08-09-2011, 08:23 AM
57. ### Which Correlation is correct?

Hi there, I'm having a bit of a problem with the last bit of analysis for my thesis. I would like to compare wave exposure of sites along the U.S....

• Replies: 1
• Views: 1,377
08-09-2011, 12:07 AM
58. ### Analysis for MSc - multiple regression?

Hi everyone, I hope someone wouldn't mind checking I am on the right track with the stats for my MSc project (recovery times in reptiles...

• Replies: 1
• Views: 1,639
08-08-2011, 11:38 AM
59. ### Linear Mixed Models in SPSS for repeated measures

I'm having trouble formulating a model with Linear Mixed Models in SPSS. I'm trying to overcome the problem of related errors due to repeated...

• Replies: 13
• Views: 12,665
08-08-2011, 04:38 AM

Use this control to limit the display of threads to those newer than the specified time frame.

Allows you to choose the data by which the thread list will be sorted.

Note: when sorting by date, 'descending order' will show the newest results first.