1. Announcement:
05-10-2017
Views:
1,909
Page 52 of 54 First ... 2 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 Last
Threads 3061 to 3120 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: 18,766
10-11-2014, 12:02 PM
1. ### Repeated measurements are negatively correlated

I have a set of data on 9 subjects. A measurement is taken every week for 10 consecutive weeks. Say I would like to compare the measurements taken on...

• Replies: 0
• Views: 2,326
01-20-2009, 03:07 AM
2. ### Randomization in an experiment

Hi, everyone. I know randomization is basically to help guarantee that the experiment at hand doesn't systematically favor any condition over...

• Replies: 0
• Views: 3,574
01-19-2009, 12:19 AM
3. ### How to do this power study?

Suppose I have a function f(x) = { 0 if 0 =< x < 0.5 { Beta=0.5 if 0.5 =< x =< 1 y = f(x) +...

• Replies: 0
• Views: 3,037
SVM
01-17-2009, 11:22 PM
4. ### Comparing Improvement Between Groups - Best Approach?

Perhaps this is an easy issue, but I wanted to throw it out anyway. I'm working on a dataset where there are two groups, both having pre- and...

• Replies: 3
• Views: 4,066
01-14-2009, 10:27 PM
5. ### Alternative to two-sample t-test when proportions are SMALL (<0.001)

Hi, I'm looking for an alternative to the two-sample (independent) t-test for equality of proportions. The two-sample t-statistic only holds...

• Replies: 0
• Views: 4,341
01-14-2009, 04:15 PM
6. ### Tricky running mean and standard deviation problem

Hi, I have a pretty tricky problem that I can't seem to solve. The basic problem can be expressed as follows: - I have a stream of data (in my...

• Replies: 8
• Views: 10,062
01-13-2009, 06:00 PM
7. ### Multivariate Statistics: Which is appropriate PCA, DFA, MANCOVA?

Hello there, I am trying to determine which multivariate statistical techniques are most appropriate to address my biological questions and type...

• Replies: 0
• Views: 5,247
01-12-2009, 04:15 PM
8. ### Power Analysis for SURVEY data

I am doing secondary data analysis on survey data that has a clustered, complex random design. I am using STATA 9.0. For the Power analysis do I use...

• Replies: 0
• Views: 4,112
01-10-2009, 07:31 PM
9. ### Symmetry Model Categorical Data Analysis

Does ANYONE understand the symmetry model for categorical data analysis by Agresti? I have a Likert scale that places students into 4 categories. I...

• Replies: 1
• Views: 3,114
12-29-2008, 12:34 AM
10. ### "Maximally uncorrelated" representation for a covariance matrix

Hi, I have a question about the covariance matrix from a real-life study in particle physics. I am working on a non-linear fit of a...

• Replies: 0
• Views: 2,167
12-20-2008, 08:16 PM
11. ### Two groups & two

Hi Wondering if anyone can help with this one. Well, several really. I am planning to conduct a study examining how easy it is to use two...

• Replies: 0
• Views: 2,189
SML
12-18-2008, 02:00 PM
12. ### Instrumental Variable?

So i have a bunch of variables: religious beliefs (how religious you are) and religious participation (how often you go to church), and demographic...

• Replies: 1
• Views: 3,384
12-17-2008, 01:24 AM
13. ### Composite Scores - Approaches to Missing Data

I have some data from an assessment form that has 25 items, all on a 5-point scale. What I'm looking at is the sum of these items. For a few...

• Replies: 6
• Views: 6,621
12-12-2008, 09:43 AM
14. ### Product pricing question

Hello all. It's been a long time since I've been on this forum. Glad I was able to find it again. I'm afraid my stats experience is limited to...

• Replies: 0
• Views: 2,791
12-08-2008, 07:41 AM
15. ### jackknife

HI all, can some body pls let me know how can i do a jackknife regression. Actually i have done stepwise regression analysis and now i have to apply...

• Replies: 4
• Views: 7,948
12-06-2008, 06:30 PM
16. ### Manova outlier cutoff

I have been reading that Manova is very sensitive to outliers, particularly for small groups. One text I read suggests using 3.5 SD as a cutoff for...

• Replies: 5
• Views: 5,873
12-04-2008, 12:22 PM
17. ### Correlation

I have a list of vehicle models and a number of costs associated with them. For example: Mazda 1000.50 euro Peugeot 2000.23 euro Mazda...

• Replies: 12
• Views: 2,863
12-04-2008, 09:32 AM
18. ### Help with analysing data

I have submitted a questionnaire indicating respondants to give their ranking in accordance to their preferred weighting - for example if they gave...

• Replies: 2
• Views: 2,456
12-03-2008, 08:12 AM
19. ### Centering for interactions in multiple regression ??

This is an e-mail about our discussion. Can someone please help us. I cannot understand any reason to center the variables other than "well it just...

• Replies: 5
• Views: 25,878
12-01-2008, 06:50 PM
20. ### Effect of Culture on Scales

I am considering implementing a study asking respondents to rate several items on 1-10 scale. In America, I know the limitations of the scale. ...

• Replies: 0
• Views: 2,157
12-01-2008, 10:57 AM
21. ### 2 x 4 Factorial Design and contrasts...

Question... I have a 2 (gender) x 4 (Drug Dose) design Gender - Male - Female Dose - 200 - 400 - 600 - 800

• Replies: 2
• Views: 12,385
11-30-2008, 11:37 PM
22. ### Factor Analysis help--Senior Thesis

I am an undergraduate and working on my senior research project. I am doing a study of the construct validity of a critical thinking test using...

• Replies: 2
• Views: 3,941
11-30-2008, 07:50 AM
23. ### Is this a vaild data transformation method?

Hello Talkstats people, I am another hopeless case who needs some help with my dissertation statistics. Basically I am not sure if the method...

• Replies: 0
• Views: 4,453
11-26-2008, 09:49 AM
24. ### When are random variables random?

I have an environmental dataset in which a treatment was carried out on a series of plots (situated on the landscape) in duplicate. However the...

• Replies: 0
• Views: 3,539
11-26-2008, 09:34 AM
25. ### Random Variables and Correlation

I claim that if x is a normal distributed random variable, and y is a uniformly distributed random variable then x and y cannot have a correlation of...

• Replies: 11
• Views: 5,682
11-20-2008, 03:47 PM
26. ### website splits - sample sizes

Id like to do some research into website splits. As visitors arrive to one of our websites (lets call it id=123), the page will randomly deliever...

• Replies: 0
• Views: 2,109
11-19-2008, 08:47 PM
27. ### Survey analysis help: what tests to run?

I'm doing research investigating why South Korean students are reluctant to speak English in ESL classes. I've developed a survey with nine...

• Replies: 2
• Views: 5,540
11-19-2008, 05:28 AM
28. ### Hypothesis design

Hi, I have a question regarding hypothesis design. In other words, how to properly assign H0 and H1. For example, if I have statement: Some drug...

• Replies: 3
• Views: 3,321
11-19-2008, 12:31 AM
29. ### What are age effects?

Any thoughts? I've been asked to find these with some data I've been working with.

• Replies: 2
• Views: 2,364
11-18-2008, 10:33 AM
30. ### help with sequential type of tests in statistics for hyppothesis testing

my research topic is sequential type of tests in statistics for hyppothesis testing and i have been told to coollect atleast 20 sequential type...

• Replies: 0
• Views: 2,106
11-18-2008, 10:13 AM
31. ### Question on Log-Likelihood. Thanks in advance.

Question is: There are two lists of data, Y and X. Y is either 1 or 0, and X can be any number. And I have a logistic regression of Logit=B1*X, where...

• Replies: 2
• Views: 2,529
11-17-2008, 12:28 PM
32. ### non-parametric test for repeated measurement

Hello everyone, I would like to know if some non-parametric test is available to asses wether 2 samples come from the same distribution for repeated...

• Replies: 4
• Views: 5,383
11-17-2008, 04:34 AM

Alright, so honestly, I've actually looked up in both my textbooks as well as online tutorials for simplified explanations as to how I can solve the...

• Replies: 0
• Views: 2,271
11-17-2008, 12:18 AM
34. ### finding data trends

I have a dataset that includes four replicates of 7 different concentrations of pesticides applied to a plant. After exposure the number of offshoots...

• Replies: 2
• Views: 3,623
11-16-2008, 03:31 AM
35. ### How to model time-dependent covariate in random effect model?

I am using a random effect model to examine the effect of several covariates on the outcome variable over time. Some of the covariates are...

• Replies: 3
• Views: 9,835
11-14-2008, 06:37 PM
36. ### Pilot Study Numbers

What is an appropriate number of responses for a pilot study? I'm trying to find something in the literature to support the size. Specifically, since...

• Replies: 4
• Views: 14,284
11-11-2008, 01:27 PM
37. ### Factor Analysis Question

Hi everyone, I'm a Trainee Clinical Psychologist, not a statistician but we have research to do as part of our training so I'm hoping someone here...

• Replies: 5
• Views: 3,277
11-10-2008, 04:27 PM
38. ### doctoral research

I would like help with posting and or and analylzing the results of mail surveys on collaboration onto SPSS.

• Replies: 3
• Views: 2,584
11-10-2008, 02:13 AM
39. ### Help with thesis research on social bookmarking

Hi, I'm writing my thesis right now and I must admit that I underestimated the complexity of the required statistics a bit. My description is quite...

• Replies: 1
• Views: 2,689
11-07-2008, 09:54 PM
40. ### Age-Matching Groups Who Differ on Age

I have two groups of children, A and B. Group A is the treatment group and has an age range of 5-7 years old. Group B is the control group and has an...

• Replies: 4
• Views: 5,838
11-06-2008, 02:17 PM
41. ### Correlation/Regression using Aggregrated Data

Hi, This is something that I've been wondering about for some time now, but which I've never managed to find a formal reference for....

• Replies: 0
• Views: 3,211
10-30-2008, 07:44 AM
42. ### Poll: PCA, FA, CFA, latent variables, and making a scale.

Hi! I was wondering if anyone had any suggestions for me. I'm working with two datasets. One contains a population of cases (n=25) from 2005, and...

• Replies: 1
• Views: 4,345
10-28-2008, 12:13 PM
43. ### Principal components interpretation

I have principal components based on correlation matrix. Statistica PCA method report outputs not only factor loadings that depend on components'...

• Replies: 5
• Views: 3,933
10-24-2008, 04:26 AM
44. ### Two Stage Least Squares Regression

I am trying to test a model and have been advised that 2SLS is the appropriate method. I am using SPSS which has the 2SLS option. My problem is that...

• Replies: 0
• Views: 5,041
10-19-2008, 06:35 AM
45. ### Quick Question about Null Effects in ANOVAs

Hi all, I just have one quick question: I've been analysing a reasonably large experiment recently using a repeated-measures ANOVA (with a...

• Replies: 2
• Views: 3,329
10-19-2008, 06:06 AM
46. ### Expected Value of a Sample Range

The function for the expected value of a sample range is given on the following page. http://www.jmu.edu/docs/sasdoc/sashtml/qc/chapc/sect9.htm ...

• Replies: 7
• Views: 17,522
10-16-2008, 07:34 PM
47. ### Stat guidence for a research paper

I am currently in the process of writing up a small research paper, but I am quite rusty on my stats. I was wondering if anyone could recomend either...

• Replies: 1
• Views: 2,920
10-16-2008, 02:01 AM
48. ### Multivariate Analysis assistance needed

I have conducted a survey on online privacy sensitivity. Part of the survey used a previously-proven instrument to generate a Privacy Sensitivity...

• Replies: 4
• Views: 3,457
10-14-2008, 07:42 PM
49. ### Bayesian Logistic Regression

I have the following logistic regression problem I am trying to solve using bayesian approach. " We consider a logistic regression setting where...

• Replies: 0
• Views: 3,155
10-13-2008, 03:09 PM
50. ### concordance of two sets of data

here is my problem: for a set of genes i have an expected(predicted) phenotype and an observed phenotype. i need prove that the level of...

• Replies: 0
• Views: 3,386
10-13-2008, 12:29 PM
51. ### A Simple Meta-Analysis query

Hi All, I am working on my first meta-analysis project and this may sound silly, but I am having difficulty deciding which studies to include. ...

• Replies: 0
• Views: 2,454
10-10-2008, 04:50 AM
52. ### Interval Level

Could anybody help with game theory in accordance to penetrating a market? Thank you for your answers!

• Replies: 1
• Views: 2,892
10-08-2008, 02:11 PM
53. ### A nice easy one about Repeated Measures ANOVA

Hello! A basic question from a not-very-statistically-savvy person: I have data from 2 groups of patients who underwent knee replacement...

• Replies: 5
• Views: 6,505
10-07-2008, 01:00 PM

Hello I am working with a likert scale with response ranges from 1-5. A score of '3' indicates a neutral response. I want to calculate whether,...

• Replies: 5
• Views: 6,507
10-06-2008, 07:40 PM
55. ### which statistics to apply?

Purpose of my study is to understand better how the experimental lines I am using compare to the positive and negative controls under untreated or...

• Replies: 1
• Views: 2,499
10-06-2008, 09:15 AM
56. ### help choosing LDA situation to implement

Hey all, I am a comp sci grad student interested in pattern recognition, and have been told that LDA is a good place to start before moving into...

• Replies: 0
• Views: 2,454
10-06-2008, 01:00 AM
57. ### Urgent-Statistical Test comparing means of unknown distributions

Is there a non-parametric test with which one can reject the null hypothesis of an equal mean (μ1 = μ2) between two sample distributions, over an...

• Replies: 1
• Views: 5,069
10-04-2008, 02:40 PM
58. ### Looking for a better answer, if there is one (Puzzle)

I've worked out a solution to a problem, but I was wondering if there might be a better way to do this. I'm using a computer to calculate these...

• Replies: 1
• Views: 2,624
10-04-2008, 11:24 AM

Page 52 of 54 First ... 2 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 Last

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.